1. THE UNIVERSITY OF NEW SOUTH WALES
SCHOOL OF PHOTOVOLTAIC AND RENEWABLE ENERGY
ENGINEERING
Thermal analysis of a prefabricated building model
Naman Uppal
Bachelor of Engineering in Renewable Energy Engineering
Course Code: SOLA4911 Thesis Part B
Submission Date: June 2015
Supervisor: Associate Professor Alistair Sproul
Assessor: Dr. Santosh Shrestha
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Certificate of originality
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Date: 02/06/15
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I. Abstract
This thesis conducts a thermal analysis on the Hadrian Villa, an architecturally
designed two-bedroom residence that uses the Origination &U system. The &U
system is a prefabricated modular building model. The skeletal structure for the &U
design is made using lightweight fiber reinforced plastic. Heat transfer is a common
issue and concern for lightweight prefabricated housing, as is explored further in this
thesis. The main objective of this thesis is to understand how the Hadrian Villa will
perform in Australian climatic conditions and how low energy building techniques
can be implemented to reduce the thermal energy requirements for the design.
The analysis for this thesis is conducted in two sections. Firstly, preliminary
calculations are conducted to determine the thermal resistance of the wall panels.
These calculations indicate that the wall panels have an R-Value of 2.25m2
K/W to
2.57m2
K/W, varying according to the design choices of each face of the building.
Secondly, these values along with material and construction data are applied to the
AccuRate building software, to calculate the total thermal energy load of the building.
It is found that the basic Above Ground design has a base thermal energy load of
70.4MJ/m2
.annum, which is classified as below thermal performance standard
established by the BASIX thermal comfort protocol. Improvements are implemented
to increase the thermal efficiency of the design. Using low energy building
techniques, the building is improved to a minimum thermal energy load of
30.3MJ/m2
.annum. This brings the building clearly within thermal protocol
requirements of 39MJ/m2
.annum.
To determine where this model is applicable, the Hadrian Villa simulations are tested
across different cities of Australia using the AccuRate software. It is found that design
performs best in Sydney, Brisbane and Wollongong, with a minimum thermal energy
load achieved in Sydney, as a subtropical climate. The Hadrian Villa is found to
perform worst in Darwin.
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II. Acknowledgements
The author would like to acknowledge some of the people without whom this thesis
would not have been possible.
Firstly, the author would like to extend his sincere gratitude to the supervisor of this
thesis, Associate Professor Alistair Sproul (Lecturer and Postgraduate Coordinator,
University of New South Wales). His lectures on Low Energy Buildings are what
sparked the author’s interest in this area of study. Alistair’s readiness to work with
students and industry are what allowed the author to find a thesis that related to a real
world project. His consistent reminders for meetings, encouragement to explore new
and different ideas, vast theoretical and industry knowledge, combine with unending
humour and relaxed attitude are what pushed the author to carry on through each
stage of the thesis.
Secondly, the author would like to thank the team at Pidcock and Origination.
Caroline Pidcock (Director of Pidcock Sustainability + Architecture and Origination
Pty. Ltd.) and Fergal White (Associate Director of Pidcock Sustainability +
Architecture) were an immense help throughout the thesis. The author truly
appreciates them offering their office space and resources, regular time for meetings,
consistent feedback and inclusion of the author in office festivities. It was a pleasure
for the author to be a part of the &U project, and he wishes the greater team
maximum success in this venture.
Lastly but importantly, the author would like to extend a hearty appreciation to his
mentors, friends and family. To each of them who spent the time to understand the
thesis work, ensured the author kept calm and balanced and provided their love and
support, the author is indebted.
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1. Introduction
1.1 Area of study
Prefabricated modular building has become an increasingly popular option for both
the residential and commercial sector. Modular building relies on premade units;
building components such as walls, beams and floors or fixed rooms, which attach to
form entire floors or complete buildings (Retik and Warszawski, 1994). The
advantages of prefabricated systems are with respect to their ease of manufacture, in
controlled factories and warehouses. This allows them to be produced at any time of
the year with little to no interruption by weather or contractor coherence issues. This
reduces overall build time on site, and hence resource allocation can be more
efficiently managed.
The fundamental issue with prefabricated structures is the building material. They are
usually lightweight, integrated structures. This means they have little resistance to
heat transfer, making for thermal inefficient buildings. The challenge is to find
methods to increase the building’s thermal resistance to heat transfer, with additional
materials and design techniques.
1.2 Current state of affairs
Research in the field of prefabricated building is limited, as commercial interest has
come largely in the last 20 years (prefabAUS, 2015). There are examples of modern
prefabricated models being implemented during war periods and after (prefabAUS,
2015). However the reception of the building industry to develop prefabricated
models on a large scale has only been more recent (prefabAUS, 2015). Hence, there is
limited development on best design practices, and limiting prefabricated design
specific problems. This considered, there are large scale developers facilitating
projects for prefabricated housing, such as Sekisui House (prefabAUS, 2015).
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1.3 &U building system
The &U is a prefabricated building modular house design, developed by Origination
Pty. Ltd.. Using a series of interlocking wall panels, multiple designs can be created
in a multitude of locations to meet the needs of a client (Pidcock and Pidcock, 2011).
Designed with Fiber reinforced plastic, &U panels are lightweight and easy to install.
The panels are 140mm thick (see Figure 3-2), designed with an air gap between the
faces of the panels, which allows insulation, wiring and building structures to be run
through this space. House designs can vary from small villas (the model tested in this
thesis) to large houses and small apartment blocks. As the panels are modular, the
house is constructed like a jigsaw with multiple pieces. This can create an issue for air
gaps and thermal bridging. Lightweight construction also represents low thermal
mass. Thermal mass is traditionally keystone to good thermal performance of a
building. A method would need to be found to address both of these issues, and
develop and potential solutions. (Pidcock and Pidcock, 2011)
1.4 The Hadrian Villa
Inspired by the architectural style and setting of Hadria, Italy, the Hadrian Villa is one
of the Origination &U building designs, as developed by Pidcock Architecture +
Sustainability (Pidcock and Pidcock, 2011). The design consists of a central open
Kitchen Living and Dining (KLD), two bedrooms, a Laundry and Bathroom. In the
centre of the Hadrian Villa are two integrated water tanks, separating the bedrooms
and KLD. The north face of the Hadrian Villa leads the KLD to a shaded deck area.
The open floor plan and integrated roof space allow the Hadrian Villa to have ceiling
heights between 2400mm in the centre, to 3900mm along the perimeter. The reverse
racked roof allows for these high perimeter ceilings to incorporate high-level
windows, allowing more natural lighting into the building. The floor plan of the
building envelope spans a rectangular shape, 12720mm along the north and south
faces, and 9720mm along the east and west faces. The Hadrian Villa is being
designed as an above ground building, built on 400mm high stilts. For the purpose of
research and experimentation, it is also being tested with a concrete floor model. The
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Figures 1-1, 1-2, 1-3 and 1-4 below demonstrates the general design and floor plan of
the Hadrian Villa. Detailed images utilised for measurements are included in the
appendices.
Figure 1-1: Hadrian Villa North Face
Figure 1-2: Hadrian Villa East and West Face
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Figure 1-3: Hadrian Villa Kitchen Living Dining Area
Figure 1-4: Hadrian Villa Floor Plan
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1.5 Objectives of research
1.5.1 Thesis statement
To conduct a thermal analysis on an Origination &U prefabricated house design. This
thesis aims to find methods to increase the thermal efficiency of the building by
modifying and adding specific design techniques and materials.
1.5.2 Motivation
This thesis is focused on Low Energy Building concepts. It applies a theoretical
understand to practical design. The thesis will have a direct impact on the way things
work, making a positive contribution to societal development. This reflects the
author’s passion for engineering. It is important that engineers consider how best their
work can utilise the resources efficiently for the least impact solution to ongoing
issues. Housing and efficient use of energy are key in the adaption method for climate
change.
1.5.3 Thesis objectives
There are three established objectives of this thesis.
1. To determine the current heating and cooling load for the &U selected design.
2. To understand the effects of various building materials and techniques:
- Floor Structure
- Glazing
- Thermal Mass
- Water walls
- Phase Change Materials
- Insulation
- Thermal Bridges
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3. To test the performance of the given &U design in a range of climatic zones.
1.5.4 Thesis scope
By testing one specific &U design, the research shall determine the yearly cooling
and heating load by simulation in the AccuRate Software. From this understanding
improvements can be implemented as per the literature review and further simulations
conducted. This is in efforts for to influence Pidcock in affirmative decisions on how
they may finalise their designs.
1.5.5 Hypothesis
In implementing theoretically supported changes to the current design, significant
improvement in the thermal efficiency of the building can be expected. Changes
should have a collaborative affect, however impacts should be considered individually
too.
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2. Literature review
The literature review summarises findings of some key sources researched to
understand and develop the thesis work. The research is separated by the information
related to the thesis objectives.
2.1. Previous studies
Automated Design of Prefabricated Building (Retik and Warszawski, 1994)
Retik and Warszawski’s paper describes “a knowledge based system for the detailed
design of prefabricated building”. The automated system takes given input data from
an architectural design, and develops modular grids to represent individual floor and
wall elements. These grids can finally produce element drawing and costs.
Retik and Warszawski highlight two main types of prefabricated building: Planar
elements and Three-Dimensional spatial units. The Origination &U design utilises
planar elements building. This refers to units where walls and structures are made, not
entire rooms.
The advantages of this style of automated design include; use of an integrated
computer construction that saves work of manual drawing and cost estimation; an
“expert system” that can save human effort and enhance design quality; and a system
that requires less involved participants to develop and construct.
Disadvantages of an automated design include: a rigid design that is conformed to
rules and laws set in premade designs; difficulty in coordinating knowledge from
different design disciplines such as architectural knowledge, structural engineering &
industrial production technology; a computer driven manipulation of graphical
representation which is conformed strict rules; and different methods which at each
have some level of error, consequently sacrificing clarity for detail and vice versa.
The &U design avoids these issues as the prefabricated models are already applied to
formulated designs, as compared to entering a new design and finding a prefabricated
design for this model. Consumers are then however limited for choice.
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Exploring the zero energy house concept for Sydney (Bambrook et al., 2009)
Bambrook et al.’s paper explores the concept of a ‘zero energy house’, with
minimised heating and cooling loads on the building. Any energy requirements are
supplied by a photovoltaic thermal system annually. The building tested is modeled
using IDA Indoor Climate and Energy (IDA ICE) simulation program.
Bambrook et al. determine important aspects of low energy building to be “design
suited to climate, orientation, floor plan and dimensions, thermal mass, building
envelope construction and insulation, windows and shading, ventilation and
infiltration, and internal gains (due to occupants, lighting & appliances)”. These
provide some key ideas for some of the main concepts explored in the thermal
analysis of the &U design.
Bambrook et al. discuss the use of thermal mass. “For thermal mass to make a useful
contribution to a low energy house it should be located inside the building and be well
insulated from the outside”. This sustains a key consideration for how thermal mass
should be implemented in the &U house. “It is better to have a greater surface area of
thermal mass at 50mm thickness than a smaller surface area of thermal mass at
100mm thickness (Chiras 2002).” Bambrook et al. expresses that it will be key to
have as large an area of thermal mass present all through &U house, as compared to
high concentrations in specific areas. Experimental data showed that adding more
thermal mass will produce diminishing return; hence it would be important to
determine similar point of excess thermal mass for the &U house.
“The optimal insulation thickness with respect to space heating energy is obviously as
thick as possible”. For the &U house, as a lightweight construction material, more
insulation would yield better results. Pidcock are aiming to put at least 100mm of PIR
insulation. In Bambrook et al.’s experiments, greater insulation decreased the heating
load. However, insulation greater than 700mm thickness (in this example) and cooling
loads began to rise causes excessive heat to be retained. Hence it will be important
again to determine the ideal amount of insulation for the &U house.
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A Comparative Study of the Thermal Performance of Building Materials (Elias-Ozkan
et al., 2006)
Elias-Ozkan et al. reviews a range of building structures based on different materials
to find ideal thermally performing material in Sahmuratli, Turkey. Elias-Ozkan et al.
use Ecotect software for their thermal analysis and modeling. The paper also states
that building materials respond differently to different climatic conditions – similar to
Bambrook et al.. This verifies the importance of testing multiple locations for the &U
house to understand what thermal tools will be most useful in different climatic
conditions.
The experimentation and results depict that materials of a high thermal mass
experience less temperature fluctuation and lower heating and cooling loads. Again,
this reinforces that high thermal mass will significantly improve thermal performance
of &U house. Further, the prefabricated structure is lightweight and hence experiences
higher fluctuations, further proving the need for significant thermal mass. For the &U
design, this can be achieved with a “water wall” feature, and the use of phase change
materials.
Simulated and Measured Performance of an 8 star Rated House in Sydney (Copper
and Sproul, 2011)
Copper and Sproul compare measured heating and cooling loads for a specific house
compared to the experimental loads simulated through AccuRate and EnergyPlus
software. AccuRate and EnergyPlus showed largely similar result for thermal
analysis. Main differences appear in rooms not coupled to the outdoor environment.
Thus, a similar outcome potential for the &U house can be inferred. Specifically, use
of the Hadrian Villa with no internal only zones may produce a similar result; this is
not possible with the current design. Inherently, it is difficult to make an adjudication
on which modeling system is more accurate. After building, real collected data would
provide more clarity, at which point a better comparative analysis be conducted. For
now, either modeling software is applicable and valid.
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Copper and Sproul discuss considerations for thermal input energy and how it impacts
thermal mass in the building. EnergyPlus does allow user to input ground thermal
mass slab data. AccuRate has fixed system requirements for heated and cooled
thermal mass, and hence assumes a thermally charged mass at all times. This may
make EnergyPlus a more accurate analysis tool. It should be noted that there are other
limitations in utilising EnergyPlus compatible softwares in the method of applying a
model and specifying run data to provide relevant results. By experience, AccuRate
proves to be significantly easier to apply and use.
Simulation data compared to measured data show a significant variance. Importantly,
“AccuRate suggests that 2224 heating degree hours would be required, which is less
than half the amount of heating degree hours, 5126, as determined from the measured
sensor data”. However, EnergyPlus data would inherently show similar discrepancy,
so neither should be downplayed. The &U analysis should be conducted with
understanding that simulation software can be flawed.
Suitability of the Passivhaus Standard for Low-Energy Housing design in Australia
(White, 2013)
White “investigates the use of the Passivhaus Standard in Australia”, a German-
designed low energy building standards model. The paper has greater relevance to the
testing for &U house, as it “compares the external envelope U-values required, of a
reference apartment building in the various climate regions of Australia” to see how
well the German model could be applied here. This is valuable as it identifies issues
that could occur in the Australian environment. For the purpose of this thesis, the
relevant data comes from the profiling and research of theory for low energy building.
White’s review of precedent studies compared to Building code and Passivhaus
compliance requirements highlights that U-Value required of materials can be
significantly lower if building has airtight constructions. For the &U study, this may
be outside the scope due to limitations in feasibility of study.
Whites review of precedent studies compared to Building code and Passivhaus
compliant requirements highlights that U-Value required of materials can be
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significantly lower if building has airtight constructions. For the &U study, this may
be outside the scope due to limitations in feasibility of study.
White explains temperature profiles of major Australian cities:
o Darwin, tropical wet and dry climate. Reference building required no
heat energy due a high average mean temperature. Excessive insulation
not useful, use of triple glazing on windows had a detrimental affect –
efforts to keep heat from transferring into building envelope,
inadvertently kept internal heat gains inside the envelope.
o Alice Springs, hot desert climate. Reference building required high
heating and cooling energy. High levels of insulation required for this
climate. However excess insulation showed a diminishing return
(hence, there is a need to find optimal insulation in this climate).
o Perth, subtropical dry summer climate. Relatively low summer mean
ambient temperature. High levels of insulation not required for
building studied, however double-glazing of windows was able to
counteract heating and cooling energy demand.
o Sydney, humid subtropical climate. Relatively low mean ambient
temperature, with high humidity. No need for high levels of insulation,
did however implement triple glazing. Able to significant reduce
heating and cooling requirement.
o Melbourne, oceanic climate. Lowest mean ambient temperature, solar
irradiation and second lowest humidity of all climates tested. Hence,
reference building implemented both high levels of insulation and
double-glazing for reduction in heating and cooling loads.
The information of climatic response to thermal control materials will act as a guide
and comparison on what methods should be implemented to the &U design in order to
minimise heating and cooling loads in different climates. It should be noted that the
building tested in this paper is not for prefabricated lightweight construction. Further
research will need to be conducted to understand the differences this will have
specifically to the &U design.
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From the above research in the area of low energy buildings, some key ideas can be
articulated to guide this thesis’ research. There are certain materials and thermal
performance measures that are necessary to work with – insulation and thermal mass,
and further it will important to identify methods that work specifically well for
lightweight construction.
2.2 Thermal building design
2.2.1 Insulation
Thermal Mass and Thermoregulation: A study of Thermal Comfort in Temperate
Climate Residential Buildings (Parsons, 2011)
Parsons examines how thermal mass and other thermal regulation tools influence
thermal performance of buildings in Hobart. Parsons identifies that insulation is
primarily used to reduce heat flow: into buildings in summer and out of buildings in
winter. There are two main types of insulation: reflective and bulk. Reflective
insulation reduces thermal radiation back into the living space of a house, placed in
air space of house. Bulk insulation made of thermally resistive materials to prevent
heat transfer in and out of building envelope. Insulation also prevents moisture build
up in house, as well as blocking sound. It would be integral to understand how
insulation would perform in the given model.
Performance characteristics and practical applications of common building thermal
insulation materials (Al-Homoud, 2004)
Al-Homoud’s research presents the basic principles of thermal insulation, determining
performance characteristics of different types and where they should be implemented.
Al-Homoud identifies multiple benefits associated with use of insulation. Importantly,
Al-Homoud identifies the addition thermal comfort achieved with the use of
insulation, with less reliance on heating and cooling systems, sustaining an increase in
duration of thermal comfort indoors. Similar to Parsons, Al-Houmoud also identifies
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the ability for insulation to reduce the heat flow in and out of the building envelope,
hence improving periods of indoor thermal comfort.
The &U design would certainly benefit from the use of insulation. Al-Homoud’s and
Parson’s paper both identify that varying types of insulation available. For the &U
design, Pidcock have selected 100mm polyisocyanurate (PIR) insulation (Proctor
Group Australia, 2014). This has worked well in their previous projects and hence its
utilisation in this project.
2.2.2 Thermal mass
The role of thermal mass on cooling loads of buildings. An overview of computational
methods (Balaras, 1995)
Balaras looks at the factors affecting thermal mass performance and the effectiveness
of thermal mass on energy conservation. Thermal mass allows for the slow release of
solar gains through the day, absorbs solar energy. Hence, thermal mass is key for a
location with diurnal temperature swings. Balaras further highlights that thermal mass
is affected by thermal properties of the material, location and distribution,
combination with insulation, ventilation and occupancy. Hence, to increase thermal
performance of the &U design, diurnal opposing heat absorption and release from
thermal mass can be utilised.
Effect of thermal mass on the thermal performance of various Australian residential
constructions systems (Gregory et al., 2007)
Gregory et al. model the impact of thermal mass on a range of building styles in
Australia. The paper utilises AccuRate to model the buildings tested. Interestingly,
they recommended that the rating of the house should aim to be 6-7 stars. Gregory et
al suggests that a rating beyond 7 stars would not interact enough with the
environment. AccuRate provides a least energy consumption case. Hence, in the
model being tested, more windows will require more thermal mass (among other
building materials) to maintain or reduce thermal energy requirements.
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Gregory et al. find that thermal mass works best in Rendeered brick veneer. As the
&U design is based on lightweight construction, the effect of thermal mass may vary,
and hence provided a good opportunity to provide new information to the industry.
Detailed energy saving performance analyses on thermal mass walls demonstrated in
zero energy house (Zhu et al., 2008)
Zhu et al investigate the thermal function of an insulated concrete wall system on a
zero energy building. The paper describes that seasons can greatly impact the thermal
performance of a building. Hence, it is key to find a balance of building choices for
ideal yearly performance. This coheres to Balaras and will be key when exploring
different locations for the &U model. Note, as the Hadrian Villa testing focuses on
one location for the base design improvements, it is difficult to ordinate and redesign
in different locations. However, the research in one location will help us understand
how it performs in other locations as well.
Zhu et al. use Energy10 for modeling (NREL software), which further exemplifies
that many systems are available for modeling of thermal performance.
Zhu et al. describes the use of a Mass wall system, concrete, insulation, and plaster
board, which proved to have a much better thermal performance. Similar to Gregory
et al., this embodies that the effects of thermal mass may change with lightweight
construction. Further research and modeling will identify how well thermal mass
operates in the &U lightweight design.
Performance characteristics and practical applications of common building thermal
insulation materials (Al-Homoud, 2004)
Al-Homoud also considers the performance of thermal regulatory materials. Al-
Homoud also identifies that the use of thermal mass will be affected by climatic
condition. Thermal mass has significance in controlling temperature swings in hot dry
climates, as it initiates a time lag for heat dispersion. This is synonymous with
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information presented in other literature, describing the diurnal swing reduction with
thermal mass.
Thermal Mass and Thermoregulation: A study of Thermal Comfort in Temperate
Climate Residential Buildings (Parsons, 2011)
Parsons research identifies that thermal mass regulates peaks and troughs of thermal
fluctuation, and mitigate swings. He advises that it can be placed into or between
living space, and can be in the form of concrete, water, and phase change material
(PCM).
For the &U design, alternative options of thermal mass, such as water and phase
change material are vital, as area and volume available are restricted. Further, with
prefabricated constructions, these materials are ideal and can be easily implemented.
As the Hadrian Villa is designed to sit above ground, floor concrete may not be ideal.
Hence modeling water and PCM becomes more crucial to negate diurnal swings.
2.2.3 Phase change material
Experimental investigation and numerical simulation analysis on the thermal
performance of a building roof incorporating phase change material (PCM) for
thermal management (Pasupathy et al., 2007)
Pasupathy et al. illustrate the numerical analysis for phase change materials (PCM).
PCM utilises latent heat storage. This makes PCM a very attractive material due to its
high-energy storage density and isothermal behaviour during the phase change
process. Similar to thermal mass, it can reduce the total number of air changes in an
area, and reduce range of temperature change. Pasupathy et al.’s case looked at PCM
panel above a slab of concrete in the roof. At night, the phase of PCM would change
from liquid to solid, rejecting heat into ambient and inside air.
The functionality of PCM relies on melting temperature of PCM, type of PCM,
climate, and design and orientation of building. For the &U model concrete slabs
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could not be used. However, other forms of PCM may be able to suit the construction.
Pidcock plans to implement the use of BioPCM M51 (PhaseChange energy solutions
Australia P/L, 2015a).
PCM thermal storage in buildings: A state of art (Tyagi and Buddhi, 2005)
The paper by Tyagi and Buddhi presents a comprehensive review of various possible
methods to implement PCM into buildings. Tyagi and Buddhi describe that the PCM
is beneficial if it is heavier than the roofs/walls around them, as they are able to
absorb fluctuations of heat from outside. This should be achievable as the panel
structure for the &U design is lightweight pultruded plastic.
The ideal PCM properties are: melting in desired temperature range, high latent heat
of fusion per unit volume (low volume), significant sensible heat storage, high
thermal conductivity, small volume change and small vapour, constant storage
capacity of heat.
Commonly used organic PCMs have phase change in 20-32o
C. This is most likely to
be the choice of PCM in the &U house, and will be further looked into for product
specific details.
Tyagi and Buddhi highlight that PCM has uses in building walls, trombe walls,
wallboards, shutters and building blocks. There are limited opportunities for PCM in
the &U design beyond walls and ceiling, however it will be applied wherever best
possible. Currently, it will be modeled in the ceiling.
Phase change material-based building architecture for thermal management in
residential and commercial establishments (Pasupathy et al., 2006)
An earlier paper by Pasupathy et al. describes more about how PCM can be applied to
constructions. The paper explains that PCM provides high-density storage over small
temperature window. Further, it can aid human comfort and reduce air changes.
Pasupathy et al. highlight a range of applications for PCM; in building materials as
solar heat storage, concrete impregnation, dry wall impregnation, wood lightweight
23. ! 17!
concrete, frame walls, windows; space heating; cooling systems. This provides
promising information for PCM application to the &U model.
2.2.4 Thermal bridges
Experimental and numerical characterization of thermal bridges in prefabricated
building walls (Zalewski et al., 2010)
Zalewski et al. provide a numerical characterisation of thermal bridging in
prefabricated boiling walls. Inherently, all materials with joint path connect internal to
external will have a thermal bridge. The aim of this research is to minimise their
affect. In the study, steel frameworks cause 26.2% additional heat losses to a
prefabricated wall. Using insulation in air gaps reduced heat loss by 27% and hence
thermal bridging by 17.3%. Increasing insulation thickness also significantly reduced
heat losses by 41.8%.
While the testing is different to what would result in the &U model, this study
exemplifies that thermal bridges cannot be completely negated. Rather, other
measures should be implemented to reduce their impact. Where possible, they should
be negated.
2.2.5 Floor structure
The concept of raised floor innovation for terrace housing in tropical climate (Tahir
et al., 2010)
Tahir et al. reason the use of stilt or above ground residential construction.
Traditionally, houses are built on concrete slabs, which allows for good thermal mass
for the house. This requires, however, a longer building process. Malaysian and other
South-East Asian houses utilise above ground building on stilts with the advantage of
underground ventilation, keeping houses cool. Further, above ground design retards
ground heat seeping into house. Both styles of building design (ground and above
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ground) will be test for the &U design, giving experimental data to determine which
floor structure would be best suited to each climate. While Pidcock prefer an above
ground model for ease of implementation, each will be tested for its thermal merit.
2.2.6 Glazing
Effect of fixed horizontal louver shading devices on thermal performance of building
by TRNSYS simulation (Datta, 2001)
Datta utilises the TRNSYS modeling software to test louver shading elements on
windows across cities in Italy. The aim of this research was to determine the impact
of the louvers on thermal performance. Datta highlights that shading devices must
adequately balance the heat transferred in and out of the building, as over shading
may negate the positive attributes of window. Datta’s modeling highlights that the use
of shading louvers that fully shade south facing windows can reduce heat gains by
that window by over 50%. This inherently signifies that the use of louvers can have a
significant impact on heat gains reduction for glazing.
The effects of orientation, ventilation and varied WWR on the thermal performance of
residential rooms in the Tropics (Al-Tamimi et al., 2011)
Al-Tamimi et al. study how changes to the building orientation, ventilation and
window-to-wall ratio (WWR) can impact the thermal energy required by a building.
Specifically, their study examines these affects in tropical climate. Al-Tamimi et al.’s
research highlights cases where heat gain through glazing is estimated to be 25-28%
of total heat gain, and up to 40% in hot summer/cold winter climates. Hence, Al-
Tamimi et al. advise the use of glazed windows. In the test scenarios, Al-Tamimi et
al. found that the maximum temperature difference and average temperature
difference decreased; and minimum temperature difference remained relatively close
(minor changes). On decreasing the WWR, the indoor air temperature reduced overall
air temperature. Note again that this research was conducted in a tropical climate, i.e.
hotter and more humid (Tahir et al., 2010). From this, it can be deciphered that
largely hotter or colder climates will experience more extremes in temperature
25. ! 19!
swings, the more the glazing. Al-Tamimi et al. conclude that optimal sizing for
windows is vital to negate negative solar radiation impacts. They highlight that any
walls should also utilise insulation to increase R-Value. They also conclude that Low
U-Value windows with good shading should be implemented to minimise solar
penetration.
Al-Tamimi et al.’s findings are conducive to the generally accepted theory for low
energy building, and hence are consider true and useful to the Hadrian Villa. Hence, it
is important to implement low U-Value and glazed windows with some form of
shading. Reducing window area is also tested to determine and impact, and potential
reduction in thermal energy demand.
Thermal Mass and Thermoregulation: A study of Thermal Comfort in Temperate
Climate Residential Buildings (Parsons, 2011)
Parsons’ research highlights that glazing allows sunlight to enter the building the
building envelope, and hence is vital to passive design. However, Parsons also
recognises that poor design placement of glazing can have negative affects. For
optimal glazing use, Parsons recommends glazing should be situated on the north face
as much as possible, and reduced elsewhere. Generally, too many windows (high
WWR) would reduce overall insulation levels, and propagate heat losses. This is a
vital consideration for the structure of the Hadrian Villa, with a high concentration of
windows on the north face. Parsons indicates how louvers operate and their
importance in negating summer sun but allowing winter sun into a building façade
(appendix image). Pidcock has applied louvers on the north face of the Hadrian Villa
(reference images). Parsons recognises the opportunity cost of a implementing more
windows for aesthetic purposes, which can cause excess solar gain. He highlights the
BCA’s specification and regulation around windows. Pidcock as registered architects
are assumed to have made all appropriate calculations and verifications for the
application of this design.
Parsons discusses the use of double glazed windows as a method to reduce the impact
of low wall resistance by glazing. Further, he highlights that windows should also use
shading devices. Pidcock has designed the &U models to have a dedicated device or
26. ! 20!
eave shading all windows. The louvers on the north face double as a vergola
(reference) for the verandah and window shade. Further, blinds are applied to all
windows of the design. Parsons advises the use of reflective coatings and low e glass.
While Pidcock utilses Hampton & Larrson low e Double Glazed windows for its
designs, to match U-Value and solar heat gain coefficient, Airlite Double Glazed
window with low e glass are used in AccuRate. This may have an impact on thermal
performance that is different to the actual windows, but it is expected to be
insignificant.
Overall, Parsons provides a very detailed and well-referenced theory for glazing
principles and application. Hence, it is reasonable to utilise this understanding for the
building principles applied for the Hadrian Villa. As such, the Hadrian Villa is largely
aligned with these principles, and minimal changes need to be applied. Rather, they
are used to enhance the design.
2.2.7 Theoretical calculations
Heat Transfer – A practical approach. Second Edition. (Cengel, 2002)
To understand how the overall resistance of the pultruded parts of the &U design can
be calculated using thermal resistance networks. Cengel explains that this concept can
“be used to solve steady state heat transfer problems that involve parallel layers or
combine series-parallel arrangements”. For the &U design, multiple parallel layers of
series networks can be modeled to conduct an R-Value calculation. By this modeling,
the Hadrian Villa is assumed to interact in a steady state, where all thermal energy
enters through the wall surface analysed.
The analogous thermal transfer formulae is as follows:
! =
!! − !!
!!"#$%
27. ! 21!
where the heat transfer between two points is described by the temperature difference
of the two points, divided by the overall Resistance of the system. Note, R total can be
calculated from the following formulae for parallel networks.
!!"#$% =
!!!!
!! + !!
This formula applies for a two parallel resistance network.
In the case of multiple resistances, the individual resistance series must be weighted
when the R-Value is calculated. This method utilises an area fraction calculation.
Cengel highlights an example of this on page 180. This example is used as the method
for theoretical calculations of the &U panel R-Values.
!
!
!
!
!
!
!
!
28. ! 22!
3. Methodology
The aim of this thesis is broken into three main sections.
1. To test how the &U Hadrian Villa design performs in its current design.
2. To understand how changing certain aspects of the building design would
affect the performance.
3. To test these models in a variety of locations to determine where this design
will perform best.
3.1 Excel calculations
Stage 1 of the aims involves modeling the entire house. In order to model the house in
AccuRate, the final R-Values are required. To determine an effective R-Value that
AccuRate can accept for the external walls, preliminary complex calculations must be
performed to determine a synthesised R-Value for each face.
3.1.1 Panel
Figure 3-1: Wall Panel Cross Section with Resistances
29. ! 23!
Figure 3-2: Thermal Resistance Network for &U Jointed Hook Section
The modular panels are constructed as 962mm long by 140mm wide pieces. The
panels are made of a fiber reinforced plastic (FRP) resin, by a pultrusion method
(Lyons Consulting Engineers, 2014). Each panel has outer hook joints, and the inner
section is broken into 5 separate sections with 5mm thick resin sheets. Between the
internal sections will be 100mm thick PIR insulation. Cengel eloquently exemplifies
the fractional weighting of thermal bridges on a fixed panel in “Heat Transfer – A
practical approach”, on page 180 (Cengel, 2002).
30. ! 24!
Figure 3-3: Thermal Bridge Example, from Page 180 of Heat Transfer – A practical approach (Cengel,
2002)
A similar approach is used for the &U panel, deconstructing the panel by cross-
sectional layers. This method can be summarised as follows:
1. Calculate the series resistance of an individual section of the panel
2. Calculate the parallel resistance of the panel by summing the inverse of each
section, with a fractional distribution.
The panel length is considered from 6mm into the left side of the modular panel
(where another panel’s hook joint would meet), to 6mm into the right side. This is to
accurately model the panels, as they would be connected in the Hadrian Villa.
Further, the resistance is calculated as if another hook were connected, and the resin
of two hooks is considered together.
Figures 3-1 and 3-2 above correlate to show the path of heat transfer from the outside
to inside (indicated from top to bottom). This indicates that each vertical layer can be
examined as a separate resistance. Separate resistances ensure a uniform shape (and
31. ! 25!
hence uniform resistance) to each individual section. Assuming a steady state
condition (all energy on the panel comes into the house), we can develop a thermal
resistance network (Cengel, 2002). This modeling of thermal resistance networks
vertically allows us to more easily separate the sections of the panel with varying
thickness and material composition. For the network shown in Figure 3-2; the left
and right sections represent the resistance of the hook connector sections in Figure 3-
1; the central single resistance connections in Figure 3-2 represent the resin only
thermal bridges in Figure 3-1; and the central combine resistances in Figure 3-1
represent the large thermally insulated sections, shown as gaps in Figure 3-1. Note
that while Figure 3-2 indicates a lot of “grid” like connections, only intersecting lines
with dots indicate a connection. Intersections with no dot are not interacting, and
rather are separate connections “crossing over” each other. Inherently, the calculation
for R-Value of each section is:
!!"#$%&'!!!!"!!"#$%&'
=!!!!"#$%&'!!"# + (!!"#$%!!"#$% + !!"#!!"# + !!"#!!"#$%!!"!!"#$%&'!(" + !!"#!!"# +
!!""#$!!"#$%) + !!"#!$%!!"#
!!"#$%!!"#$%#"!!"#$%&' =!!!"#$%&'!!"# + !!"#$% + !!"#!$%!!"#
!!"#$%&'()!!"#$%&'
=!!!"#$%&'!!!" + (!!"#$%!!"#$% + !!"#$%&'!(" + !!"#!!"# + !!""#$!!"#$%) + !!"#!$%!!"#
These formulae may vary according to the structure of the individual section;
however follow the same essential form. R-Values values for each material in the
panel are determine as follows.
Cengel provides that an average estimate for outdoor air and indoor air resistance are
0.03-0.044m2
K/W and 0.12m2
K/W respectively (Cengel, 2002). The FRP resin has a
tested thermal conductivity of 0.6W/mK to 0.3W/mK depending on the percent of
laminate (Lyons Consulting Engineers, 2014); hence we can calculate the according
R-Value for each sections resin thickness. For primary calculations, the resin thermal
conductivity is fixed at 0.6W/mK. Open gap sections of the panel require rubbing
32. ! 26!
seals, which have an R-Value of 0.31m2
K/W as given by Cengel (Cengel, 2002).
Cengel gives that R-Values between standard air gaps in still air spaces are between
0.16-0.17m2
K/W, within 13-90mm (Cengel, 2002). This information is compiled in
Appendix 1, displaying the full set of values and following calculations.
When the thermal conductivity is know, we can use the relationship:
! − !"#$%!(!!
!/!!) =
!
!
where the R-Value is the thickness, L, of the resistive material divided by the specific
thermal conductance, k. As all thicknesses are known and simplified from the
prototype diagrams above, and all material R-Values or thermal conductivities have
been determine, we can determine each sections R-Value.
Each section has a varied composition. Any change in resistance vertically can be
broken into a new series resistance, when going horizontally across the panel. Across
the panel, there exist 19 such resistances. R1-5 and R15-19 represent the resistances
for the jointed hook section; R7, R9, R11, R13 represent resin thermal bridge
resistances; and R6, R8, R9, R10, R12 and R14 represent insulated sections of the
panel. A detailed description of resistances is available in the Appendices.
The analysis of three resistance types is summarised, with their values displayed
below in Table 3-1.
Resistance (m2
K/W) R_Insulated R_Resin R_Jointed
Outdoor Air 0.037 0.037 -
Resin/Cover/Rubber 0.01 0.23 -
Air Gaps 0.165 - -
Resin/Insulation 4.54 - -
Air Gaps 0 - -
Resin/Cover/Rubber 0.01 - -
Indoor Air 0.12 0.12 -
Table 3-1: Wall Panel Resistance Sections
33. ! 27!
The jointed hook section is developed on 5 separate resistances. The summary for this
is provide in table 3-2 below.
Resistance (m2
K/W) R1 R2 R3 R4 R5
Outdoor Air 0.037 0.037 0.037 0.037 0.037
Resin/Cover/Rubber 0.31 0.035 0.031 0.031 0.233
Air Gaps 0.165 0.165 0.165 0.165 -
Resin/Insulation 0.043 0.03 0.0425 0.077 -
Air Gaps 0.165 0.165 0.165 0.165 -
Resin/Cover/Rubber 0.31 0.035 0.028 0.028 -
Indoor Air 0.12 0.12 0.12 0.12 0.12
Table 3-2: Jointed Hook Resistance Network
Resistance R1 R2 R3 R4 R5 R total
Total R
(m2
K/W)
1.14 0.59 0.59 0.62 0.39
Thickness
(mm)
4 5 4 6 6
Fraction 0.16 0.2 0.16 0.24 0.24
Fraction*U
(W/m2
K)
0.140 0.341 0.272 0.385 0.615 1.752
R-Value
(m2
K/W)
0.571
Table 3-3: Jointed Hook Section Overall R-Value by Area Fraction
Once an individual section R-Value is calculated, the individual series resistance
sections are summed as a parallel resistance network (Cengel, 2002). To calculate the
final panel R-Value, a fractional distribution of the R-Value is calculated. First, the
fraction of distance of an individual section compared to the total length of the panel.
!"#$%&'(!"#$%&' =
!"#$%ℎ!!"!!"#$%&'
!"#$%!!"#$%!!"#$%ℎ
34. ! 28!
Then, U (measure of thermal conductance, U = 1/R-Value) of the section is multiplied
by the fraction of the section (Cengel, 2002). This formula is developed from parallel
resistance analysis (Cengel, 2002):
1
!!
=
1
!!
+ ⋯ +
1
!!"
= !!
The effective U of the panel is calculated as the sum of all sections, and hence the R-
Value is determined.!
!!"!#$ = !"#$%&'(!"#$%&' ∗
1
!!"#$%&'
From hook, through panel, to hook on the other side, the overall thermal conductivity
of each panel is calculated.
!!"#$% = 2.98!!!
K/W
Areas without insulation, while fractionally low, have a high impact on the final R-
Value of the panel.
Resistance (m2
K/W) R_Insulated R_Resin R_Jointed R_Panel
Total R 4.88 0.39 0.57 -
Thickness (mm) 176 5 25 -
# of sections 5 4 2 -
Total thickness (mm) 880 20 50 950
Fraction 0.926 0.021 0.053 1
Fraction*U (W/m2
K) 0.190 0.054 0.092 0.336
Area Weighted R-
Value (m2
K/W)
- - - 2.977
Table 3-4: Panel Resistance Network R-Value Calculations
35. ! 29!
3.1.2 Post
The post structures in the walls of Hadrian Villa exist to provide a support skeleton.
These vertical columns are 130mm long, spanning the height of each wall room. For
thermal calculations, we model a post structure with two jointed hooks either side to
connect to other panels as is indicated below.
Figure 3-4: Post Cross Section with Hook Joints
To calculate the R-Value for the post structures in the Hadrian Villa, a similar
methodology is applied:
1. Calculate the series resistance of an individual section
2. Calculate the parallel resistance of the post by summing the inverse of each
section, with a fractional length distribution.
The post is constructed of the same resin as the panels. The post also has outer and
inner covers to create a flush surface with the panels. As the post has a generally
square shape, with some outward and inward patterns (which are largely balanced),
the post is modeled as an even, hollowed square. Hence, there are three resistance
sections added – R20, R21 and R22, representing the left solid section of the square,
36. ! 30!
the hollow section of the square, and the right solid section of the square respectively.
Figure 3-4 shows the top view of the post from outside to inside shown from top to
bottom. Furthermore, the hooks are the same as those used in the panel, and hence we
can utilise R1-5 again. Individual resistance-by-resistance analysis can be found in the
appendices. Similarly, analysis of the R_Jointed section can be found in the
appendices.
Resistance (m2
K/W) R_Centre R_Edge R_Jointed
Outdoor Air 0.037 0.037 -
Resin/Cover/Rubber 0.0083 0.0083 -
Air Gaps 0.022 0.217 -
Resin/Insulation 0.609 0 -
Air Gaps 0.022 0 -
Resin/Cover/Rubber 0.0083 0.0083 -
Indoor Air 0.12 0.12 -
Table 3-5: Post Resistance Sections
R_Centre R_Edge R_Jointed R_Total
Total R (m2
K/W) 0.827 0.390 0.584 -
Thickness (mm) 103.5 13.25 25 -
# of sections 1 2 2 -
Total thickness (mm) 103.5 26.5 50 180
Fraction 0.575 0.147 0.278 1
Fraction*U (W/m2
K) 0.696 0.377 0.475 1.548
Area Weighted R-Value
(m2
K/W)
- - - 0.646
Table 3-6: Post Resistance Network R-Value Calculations
From this, it is found that U total = 1.548W/m2
K, and hence that:
!!"#$ !!= !0.646!!!
!/!
!
!
!
37. ! 31!
3.1.3 Beam
The beam structures in the walls of Hadrian Villa also provide a support skeleton.
These structures span the breath of a 4000mm wall section, breaking at every post
structure. The beam structure also utilises two jointed hooks either side to connect to
other posts as is indicated below.
As the beam has no repeating parts, the sections are added together in as separate
resistance, without simplification. Further, where the panel and post separate
resistances run horizontally, the resistance run vertically for the beam. The calculation
process is similar to previous sections.
Resistance (m2
K/W) R_Bottom R_Top
Outside Air 0.037 0.037 0.037 0.037 0.037 0.037 0.037 0.037
Wood Cover 0.029 0.029 0.029 0.029 0.029 0.029 0.029 0.029
Air 0.165 0.165 0.165 0.165 0.165 0.165 0.165 0.165
Resin 0.033 0.017 0.017 0.017 0.017 0.058 0.120 0.120
Rubber - 0.154 0.135 0.308 0.125 - - -
Insulation - - - - - 2.31 - -
Resin - 0.067 0.167 - - - - -
Air 0.165 0.165 - 0.165 0.165 0.165 0.165 0.165
Resin 0.033 0.067 - - - - - -
Rubber - 0.154 0.135 0.308 0.125 - - -
Resin - 0.017 0.017 0.017 0.017 0.058 0.120 0.120
Air 0.165 0.165 0.165 0.165 0.165 0.165 0.165 0.165
Wood Cover 0.029 0.029 0.029 0.029 0.029 0.029 0.029 0.029
Table 3-7: Beam Resistance Sections
R_Bottom R_Top R_Total
Total R
(m2
K/W)
0.777 1.185 1.015 1.360 0.994 3.137 0.951 0.951 -
Total thickness
(mm)
0.030 0.020 0.010 0.008 0.013 0.263 0.010 0.030 0.383
Fraction 0.078 0.052 0.026 0.020 0.033 0.686 0.026 0.078 1
Fraction*U
(W/m2
K)
0.101 0.044 0.026 0.014 0.033 0.829 0.027 0.082 1.157
Area Weighted
R-Value
(m2
K/W)
- - - - - - - -
0.864
38. ! 32!
Table 3-8: Beam Resistance Network R-Value Calculations
The final calculation shows that the U total = 1.157W/m2
K, and hence:
!!!𝑎! !!= !0.864!!!
!/!
3.1.4 Window
Window data is derived from product information about the “Hampton and Larsson”
double glazed timber frame windows, a preferred choice by Origination for the &U
design. This window has a U-Value = 2.1W/m2
K, and solar heat gain coefficient
(SHGC) of 0.58.
With all the calculations completed, a heat transfer model of the Hadrian Villa can be
designed, according to the structure and use of different components in parts of the
buildings external structure.
3.2 Component to panel calculations
This information provides an understanding to the area around which the external
walls are built. From the method described by Cengel (Cengel, 2002) for thermal
bridging, the effective R-Value for each component of the external wall is calculated.
This component model is combined to create an R-Value for a complete wall face.
Table 3-9 below indicated how the components of the wall are weighted to their
fraction of the wall composition, from which an effective R-Value is calculated. Other
faces are included in the appendices. Note that this calculation is an assumption for
consistent thermal conductivity across the surface of the wall. The windows are
calculated separately as their thermal conductively is significantly different.
39. ! 33!
North
face
Area (m2
) R-Value
(m2
K/W)
Fraction Fraction * U
(W/m2
K)
Overall R Value
(m2
K/W)
Wall 13.6 2.977 0.685 0.230
Window 20.4
Post 2.664 1.161 0.134 0.116
Beam 3.6 1.829 0.181 0.099
Sum 19.864 0.445 2.249
Table 3-9: North External Wall R-Value Calculations
These R-Values calculated are then converted into a proxy thickness of insulation, to
implement the appropriate resistance in every wall face for the AccuRate System.
Table 3-10 summaries the calculated thickness for each wall face.
R-Value
(m2
K/W)
Proxy Length
(m)
Proxy Length
(mm)
North 2.249 0.090 90
East 2.432 0.097 97
South 2.574 0.103 103
West 2.322 0.093 93
Table 3-10: External Wall Resistance Proxy
It should be noted that these are the preliminary calculations for the base design.
When insulation attributes are changed in further simulation, these proxy values also
change.
3.3 AccuRate
The Hearne Software; AccuRate, Version 1.1.4.1 allows for yearly heating and
cooling data to be simulated for a given building design. Further, it allows for a
design to be tested at any postcode in Australia. The rating tool in the software
produces results in MJ/m2
.year, as well as a star rating system prescribed in BASIX
(Department of Planning & Environment, 2013).
40. ! 34!
AccuRate allows individual materials to be selected for the construction of the
building elements. These elements are used to construct the building. The
fundamental calculations for the program are based on R-Values determining the
thermal conductivity of the element (CSIRO Ecosystem Sciences, 2010). As the &U
design utilises a new FRP material which is uncommon to AccuRate software, it is
modeled using a proxy, which matches the same R-Values as the theoretical model.
This ensures that the calculations for thermal energy in the Hadrian Villa are accurate
and valid.
Other modeling software such as EnergyPlus is also available. The author of this
thesis finds that while both software are capable of similar calculations, the AccuRate
software interface is easier to use and simulation of proxies more straightforward to
implement. AccuRate also has a simple method for testing the same design in other
locations. Hence, AccuRate is selected for the modeling.
The program follows a tabular structure, entering more specific information as the
progresses. These tabs range from; Project, Constructions, Zones, Shading, Elements,
Ventilation.
The project tab allows the user to enter Client and Assessor information, as well as
specific iterations of the model so an assessor can develop new additions on designs
as they change certain features. Further, from this section the user can change and edit
the location by postcode, changing the weather data and use on heating and cooling.
The constructions tab allows users to specify building materials for each of the major
construction types in the design. In the material type, layer on layer can be added to
design an integrated structure, such as a wall with insulation. For the Hadrian Villa, as
the building style is uncommon and the materials are not readily, many proxies have
to be made which match the fundamental R-Values.
The calculated component R-Values are entered into the AccuRate Program. For the
basic design, the model follows the specifications in Table 3-11. Note, the design
utilises either proxy materials that match the R-Value of the &U design, or a similar
material construction is used where available.
41. ! 35!
Construction Material R-Value Proxy Material
Proxy
Thickness
(mm)
External Wall North FRP/Insulation/Air Gap 1.62 Polyethylene Foam 65
East FRP/Insulation/Air Gap 1.86 Polyethylene Foam 74
South FRP/Insulation/Air Gap 2.12 Polyethylene Foam 85
West FRP/Insulation/Air Gap 1.78 Polyethylene Foam 71
Window/Door Double Glazed Window 0.42
Airlite Double Hung Double Glazed
Window 16
Floor
Timber/FRP/Insulation/Air
Gap 3.00 Timber floor/R3 insulation 145
Ceiling Plasterboard/PCM 0.13 Concrete 100
Internal walls
Thermal
Mass Wall FRP/Water Polycarbonate/Water/Air/Plasterboard 1059
Empty
Wall FRP/Air Gap Timber/Air Gap 50
Roof Steel/Insulation/Steel 5.36 Polyethylene Foam 214
Table 3-11: Material and Proxy Material Summary for AccuRate
There is an anomaly in the difference in external wall R-Value for each face.
Normally, AccuRate is capable of calculating specific R-Values for a combine wall,
with any thermal bridges for example, as a preset configuration. However, the panel,
beam and columns of the external walls in the &U design cause a range of varying
thermal networks. Further, the material FRP is unavailable. Hence, a proxy is
designed, having calculated an effective combine R-Value, from the processes
described above. As the structure of each face varies slightly, a different R-Value is
associated.
The zones tab allows the user to establish the various rooms and sections of the
design. In this section, each section type is established, the volume of the section, the
floor height and maximum ceiling height, and any additional points of infiltration and
cooling (ceiling fans). For the Hadrian Villa, the zones are divided into
Living/Kitchen/Dining, two Bedrooms, a bathroom and a laundry.
The shading tab allows the user to add shading elements such as fixed shades for
windows or eaves on rooftops. This feature is useful as it can automatically propagate
the effect of shadow over a year in a specific location. For the Hadrian Villa, there is a
42. ! 36!
continuous eave of 350mm derived from the roof, and individual window fixed of
600mm on the East, West and South face. The North face also utilises adjustable
louvers onto the balcony area.
The element tab is the most detailed. In this section, the user can implement all
constructions type to the different elements. For example, a window can be added to
an external wall, and the facing direction. By entering properties of the construction,
the software is able to identify what the building design will look like, and creates an
effective image for how it will interact with the climate. Further elements such as
eaves, louvers and others can be added.
Lastly, the orientation tab allows the user to input the footprint (area) of the building,
and the azimuth or angle with which it deviates from north facing. For the Hadrian
Villa, the living area faces north.
The AccuRate software’s “Check Data” function allows the user to review any error
or warning messages. “Errors” highlights issues in the system that must be fixed
before the model can be tested. “Warnings” highlights potential concerns
considerations that may need to be reconsidered, however the model can still be
tested. Once there are no errors, the data can be run and a summary report may be
created. The report displays client and assessor details, the building’s calculated
energy requirements (standard and area adjusted), and a star rating according to the
BASIX thermal protocols (CSIRO Ecosystem Sciences, 2010). This is where the
performance of the house can be determined, and compared with other simulations.
3.4 Improvements
The purpose of this thesis is to determine the thermal performance of Hadrian Villa in
its current design, and to further determine how the design can be improved.
The first concerns addressed are those that Pidcock determine to be of highest
importance for their base design. On identifying areas of weakness in the design,
efforts are then made to develop solutions to improve the building performance.
43. ! 37!
The &U model considers two styles of building; above ground on stilts or on a
concrete slab. Above ground is more desirable, as it decreases construction time
further in not having to pour and set a concrete base. A concrete slab however does
have the advantage of adding thermal mass to the building, as well as reducing
radiated losses to the external environmental (Parsons, 2011). Both model types are
tested to determine which may perform better. Note that above ground is considered
as the base scenario. The concrete slab scenario is considered as a potential
improvement, and accordingly the better performing design is chosen for further
testing.
The beams and posts on the external walls are identified as areas of high thermal
conductance. To counteract this heat transfer, 50mm of PIR insulation is added to the
beams and posts individually, and the improved designs are simulated.
Prior to modeling in the AccuRate software, there were different designs discussed
and considered. Of specific mention, there was greater of glazing on all surfaces of
the external walls. This has been identified as an issue from the literature review
alone, and can be theoretically observed from the Microsoft Excel spreadsheet
calculations. A further reduction in glazing is conducted, removing all high level
glazing from the Hadrian Villa design.
3.5 Recommended improvements
Some options for improvements to the design are consider that may not be feasible for
Pidcock – these are theoretical scenarios for now. Their purpose is to improve the &U
design for future opportunities.
The base design as discussed above utilises timber frame double glazed windows
manufacture by Hampton and Larrson (WERS, 2014), 100mm of PIR insulation (R-
Value 4.54m2
K/W) in the walls, and 3.00m2
K/W Batt insulation in the floor. These
are the materials of choice for the &U project, and other projects conducted by the
company. To understand the impact of these materials, superior and inferior
44. ! 38!
performing materials are chosen, and the model is simulated again. From this, the
changes in heating and cooling loads are examined and ideal models are selected.
The Fiber Reinforced Plastic used for the &U construction is chosen for a range of
building, construction and safety capabilities (Lyons Consulting Engineers, 2014). On
the other hand, this material has thermally conductive at 0.6W/mK (Lyons Consulting
Engineers, 2014). For the purpose of experimentation, other thermal values for the
resin are also considered, allowing Origination to consider the impact of different
material selection.
3.6 Simulation method
The sections as described above in the Methodology (AccuRate, Improvements,
Recommended Improvements) are broken into separate simulation parts, according to
their relevance to the thesis objectives.
“Part 1: Basic Design” develops the fundamental model for the Hadrian Villa. This is
the most crucial design, as it forms the basis for all other simulations. For an above
ground scenario, the floor is filled with Batt Insulation of R-Value 3.0m2
K/W and the
villa sits on stilts 400mm above the earth. For a concrete base scenario, a layer of
concrete is added under the floorboards, and the Batt Insulation is removed. 100mm
of concrete is considered as standard, however 50mm and 150mm of concrete slab are
also tested for potential impact.
“Part 2: Concrete Floor” tests a model using a concrete base instead of an above
ground design. As is discussed in the Results, this scenario does perform better. The
Concrete Floor section is broken into two sub sections; Improvements and
Recommended Improvements. “Improvements” represent ideas put forward by
Pidcock on latter improvements to the design, and “Recommended Improvements”
highlight further ideas and experimentation as developed from the literature review.
The Above Ground section follows a similar structure, also broken into
“Improvements” and “Recommended Improvements”.
45. ! 39!
Table 3-12 below summaries the simulations, and highlights the particular changes
between simulations.
Run Type Simulation Notes
Basic
Improvements
Base Design
Above Ground
Models the Basic Above Ground design as
instructed by Pidcock
100mm
concrete floor
Models the concrete slab design with 100mm
concrete in floor
50mm concrete
floor
Models the concrete slab design with 50mm
concrete in floor
150mm
concrete slab
Models the concrete slab design with 150mm
concrete in floor
Above Ground
Beam and
Column
Insulated
Improves the Base Design Above Ground by
insulating the Beam and Column with 50mm of
PIR insulation
Concrete with
Beams and
Posts Insulated
Improves the Base Design Concrete Floor
(100mm concrete) by insulating the Beam and
Column with 50mm of PIR insulation
Concrete Reduced
Glazing
Removes all high level glazing
Improved
Windows
Applied Paarhammar tripled glazed windows
Improved Wall
Insulations
Increased wall insulation to 5m2
K/W
Half Water
Wall
Reduced the water level to half of the tank's size
Better Resin Improved the resin to 0.3W/mK
Above
Ground
Reduced High
Level Glazing
Removes all high level glazing
Improved
Insulation
Increased wall insulation to 5m2
K/W
46. ! 40!
Improved
windows only
Applied Paarhammar tripled glazed windows
Improved Floor
Batts
Increased floor insulation to 4m2
K/W
Reduced Floor
Batts
Reduced floor insulation to 2.5m2
K/W
Improved north
windows
Improved only the North windows to triple
glazed, other directions as standard
AG 0.3 resin 1 Improved the resin to 0.3W/mK, from the
Reduced High Level Glazing Simulation
AG 0.3 resin 2 Improved the resin to 0.3W/mK, from the
Improved North Face Windows Simulation
Concrete Best with
Concrete Floor
Took the best possible Above Ground Design
(AG Resin 2) and applied a 150mm Concrete
floor, and 3m2
K/W floor insulation
Best concrete
floor no
insulation
Took the previous simulation and removed the
floor insulation
Reduced
Glazing best
concrete
Went to the Reduced High Level Glazing Above
Ground Simulation, and added a 150mm concrete
floor
Best 100mm
concrete floor
From Reduced Glazing best concrete, changed
concrete floor to 100mm
Above
Ground
Best Above
Ground with
More North
Glazing
Took the AG Resin 2 model, and reintroduced
the North Face High Level Windows
More North
Facing with
Double Glazed
Windows
(k=0.3)
Reduced Best Above Ground with More North
Glazing windows to Double Glazed
More North Changed Resin back to 0.6W/mK
47. ! 41!
Facing with
Double Glazed
Windows
(k=0.6)
Fixed Louver Changed the automated louvers in AccuRate to
manual louvers
Table 3-12: AccuRate Simulation Notes
!
!
3.7 Locations
Pidcock plan to implement the Origination &U design across Australia. Hence, it is
important to understand how the design will perform in a range of climates in
different cities around the country. For relevance of testing, the Hadrian Villa is
simulated in the capital cities of Sydney, Melbourne, Adelaide, Hobart, Perth,
Darwin, Brisbane, as well as Cairns for the specific climatic zone and Wollongong as
a specific area of interest for the company. This will allow Pidcock to understand
which climates their &U design is best suited to and the nature of changes that may
need to be implemented in other specific locations.
48. ! 42!
4. Results
!
4.1 AccuRate
To best understand the progressive modeling outcomes, the simulations are explained
individually and results cumulated. Table 4-1 and Figure 4-1 below indicate each
simulations’ annual heating and sensible and latent cooling loads in units
MJ/m2
.annum, as well as a star rating based on the New South Wales BASIX rating
scheme (Department of Planning & Environment, 2013).
Simulation Thermal Energy (MJ/m2
.annum) Star
Rating
(out of 10)
Heating Cooling
(Sensible)
Cooling
(Latent)
Cooling
(Total)
Total
Energy
Basic Design Primary Design Base Design
Above
Ground
17.1 44.2 9.1 53.3 70.4 3.9
Basic Conc
Floor
4.5 20.3 6.1 26.4 30.9 6.9
Concrete Base
Experiments
100mm
Concrete
Floor
5.9 23.2 6.4 29.6 35.5 6.4
50mm
Concrete
Floor
13.2 22.5 5.5 28 41.2 5.8
150mm
Concrete
Floor
5.6 9.7 3.5 13.2 18.8 8.3
Above Ground
Improvements
Above
Ground Beam
Insulated
13.1 42.8 9.3 52.1 65.2 4.1
Above
Ground Beam
And Post
Insulated
12.4 42.7 9.2 51.9 64.3 4.2
49. ! 43!
Concrete
Floor
Experimentat
ion
Pidcock
Improvements
Concrete
With Beams
And Posts
Insulated
8.9 20 5.2 25.2 34.1 6.6
Reduced
High Level
Glazing
3.4 6 2.4 8.4 11.8 9.2
Further Testing Improved
Windows
3.1 5.1 2.3 7.4 10.5 9.3
Improved
Wall
Insulations
2.7 4.8 2.2 7 9.7 9.4
Half Water
Wall
3 5.2 2.3 7.5 10.5 9.3
Better Resin 2.8 4.9 2.2 7.1 9.9 9.4
Best With
Concrete
Floor
8.8 12.6 4 16.6 25.4 7.6
Best Conc
Floor No
Insulation
3.1 5.5 2.2 7.7 10.8 9.3
Reduced
Glazing Best
Concrete
3.6 5.8 2.2 8 11.6 9.2
Best 100mm
Concrete
Flooring
3.9 5.8 2.2 8 11.9 9.1
Best 100mm
Concrete
Flooring with
More North
Glazing
3.5 8.5 3 11.5 15 8.7
Above
Ground
Experimentat
ion
Pidcock
Improvements
Above
Ground with
Beam & Post
Insulation
12.6 43.4 9.3 52.7 65.3 4.1
Reduced
High Level
Glazing
14 15.6 4.4 20 34 6.6
Further Testing Improved
Wall
Insulation
12.9 15.3 4.4 19.7 32.6 6.7
Improved
Windows
13.9 13 4 17 30.9 6.9
Increased
Floor
12.9 15.7 4.4 20.1 33 6.7
50. ! 44!
Insulation
Reduced
Floor
Insulation
14.7 15.6 4.4 20 34.7 6.5
Improved
North
Windows
Only
13.7 14.1 4.3 18.4 32.1 6.8
Above
Ground Resin
Change #1
13.1 15.4 4.4 19.8 32.9 6.7
Above
Ground Resin
Change #2
12.7 13.5 4.1 17.6 30.3 6.9
Best Above
Ground with
More North
Glazing
12.6 18.5 4.8 23.3 35.9 6.4
More North
Facing with
Double
Glazed
Windows
(k=0.3)
13.1 21 5 26 39.1 5.9
More North
Facing with
Double
Glazed
Windows
(k=0.6)
13.8 21.3 5.1 26.4 40.2 5.9
Fixed Louver 13.9 13.3 4 17.3 31.2 6.9
Above
Ground more
PCM
12.4 14 4.2 18.2 30.6 6.9
Table 4-1: AccuRate Run Simulations Summary
51. Figure 4-1: Hadrian Villa Simulations
0
10
20
30
40
50
60
70
80
ThermalEnergy(MJ/m2.annum)
Simulations
AccuRate Simulations
Heating
Cooling
Total Energy
45
52. ! 46!
The BASIX Thermal Protocol (Department of Planning & Environment, 2013)
requires a dwelling to consume less than 39 MJ/m2
.annum of thermal energy in
Sydney (Climate Zone 17) to meet the basic thermal efficiency requirements. The
basic Origination &U design for the Hadrian Villa is only able to meet minimum
building requirements as defined in the BASIX protocol (Department of Planning &
Environment, 2013) when built on a 100mm concrete slab foundation.
On implementing the primary advice Pidcock regarding insulation to beams and
columns and reducing the high level glazing on the north surface, the above ground
design also meets BASIX requirements (Department of Planning & Environment,
2013).
Making the design as thermally efficient as possible is a primary concern for this
thesis work. From the literature review, there are multiple facets of the design that
have potential for improvement. The further testing sections demonstrate the changes
that could be implemented and their impact.
As the Hadrian Villa already meets a low thermal energy, the designs are linked one
after another for the Concrete Floor design. This means, each new simulation is made
from the simulation before it. This method progressively determines how changes
made together can affect the performance of the building. The most significant impact
to the design is ensuring that either only a concrete floor is used, or only floor
insulation is used. Both in conjunction cause a drastic increase in heating load, and
cooling load, with too much resistance to external thermal changes. Generally, most
changes have a minimal impact on the system, once the glazing has been reduced.
For the Above Ground Design, the Hadrian Villa is not able to perform as well as the
Concrete Floor Design. The Above Ground Design simulations take a different
approach, primarily developing individual changes from the same base design of
reduced high level glazing, and only create a combine effect method in the last two
designs. Hence, any simulation after reducing the high level glazing with a total
energy load of more than 34MJ/m2
.annum is a negative impact to the design, and less
than a positive impact.
53. ! 47!
The final tests in the Further Testing sections increases the amount of North Side
glazing to meet a design objective separate from the thermal energy reduction. Hence,
we find the performance decreases in this scenario.
To quantify the results determine from the AccuRate modeling, the best performing
designs are as follows. For the Concrete Floor Design, the “Improved Wall
Insulation” case, with improved windows and reduced glazing is the most efficient
model, with a total heating load of 2.7 MJ/m2
.annum, and total cooling of 7
MJ/m2
.annum, and hence a total thermal load of 9.7 MJ/m2
.annum. For the Above
Ground Design, the cumulative model “Above Ground Resin Change #2” with best
resin and better north facing windows produces the most efficient design, with a total
heating load of 12.7 MJ/m2
.annum, and total cooling of 17.6 MJ/m2
.annum, and
hence a total thermal load of 30.3 MJ/m2
.annum. These design can be rated in Sydney
as 9.4 and 6.9 Star house respectively, by the BASIX Thermal Protocol (Department
of Planning & Environment, 2013).
4.2 Location testing
Thermal Energy (MJ/m2
.annum)
Heating Cooling
(Sensible)
Cooling
(Latent)
Cooling
(Total)
Total Energy
Sydney (2000) 100mm Concrete
Floor
5.9 23.2 6.4 29.6 35.5
Improved Wall
Insulations
2.7 4.8 2.2 7 9.7
Reduced High Level
Glazing
14 15.6 4.4 20 34
Above Ground Resin
Change #2
12.7 13.5 4.1 17.6 30.3
Melbourne
(3000)
100mm Concrete
Floor
80.6 11.4 1 12.4 93
Improved Wall
Insulations
66.9 3.1 0.5 3.6 70.5
Reduced High Level
Glazing
78.3 21.2 2 23.2 101.5
Above Ground Resin
Change #2
75 19.9 1.9 21.8 96.8
Hobart (7000) 100mm Concrete
Floor
145.1 0.4 0 0.4 145.5
Improved Wall 123.1 0.1 0 0.1 123.2
55. ! 49!
Reduced High Level
Glazing
25 13.2 3 16.2 41.2
Above Ground Resin
Change #2
23.6 12 2.9 14.9 38.5
Table 4-2: AccuRate Run Summaries for Locations across Australia
Location testing provides Pidcock with information regarding applicability of their
designs in locations other than Sydney. As is identified in the methodology, Pidcock
has a specific interest in knowing how the Hadrian Villa would perform in
Wollongong, for an upcoming client project. Further, in testing major cities around
Australia, Pidcock can determine which locations this model is easily installable, and
which may require work before implementation. To determine more broadly which
locations can apply the Hadrian Villa model, four simulations are tested. The
simulations tested are: the most basic simulations where minimal thermal
requirements are met, and the most efficient simulations, for Above Ground and
Concrete Floor models primarily tested in Sydney. A summary of the location
simulation is provided in Table 4-2 above.
The metric of star rating is specifically relevant to the BASIX Thermal Protocol
(Department of Planning & Environment, 2013), and hence should not be used to
compare buildings outside New South Wales. Instead, the total thermal energy
consumed is compared between the simulations in different cities. In comparing the
buildings thermal energy consumption, it is observed that cities closest to the East
Coast of Australia (Sydney, Wollongong and Brisbane) exhibit the best performance,
and the worst performance occurs in locations of extreme cold and heat (Hobart and
Darwin).
Figures 4-2 to 4-5 below graphically demonstrate how to same models perform in
different locations.
60. ! 54!
5. Discussion
The discussion section analyses some of the results revealed by the modeling to
further understand why certain simulations perform. Potential recommendations for
further analysis are also included. The discussion is structured to examine some of the
primary research aims developed and additional considerations.
5.1 Basic design
Our primary analysis highlights that the major failure of the Hadrian Villa in the Base
Design Above Ground simulation is its high cooling (latent) load.
As illustrated Figures 5-1 & 5-2 we observe a summer and winter 60 day period,
comparing the Base Design Above Ground and the Above Ground Resin Change #2
simulations in the kitchen living and dining zone. The temperature profile graphs
indicate a dissonance in the simulations performance in Summer, and similar
performance in Winter. Specifically, the Base Design experiences (red) maintaining a
higher, more limited band of temperature, generally between 25-30o
C. While the
temperature of the Above Ground simulation experiences greater fluctuations, the
temperature is closer to thermal comfort, and hence less energy is dedicated toward
cooling in that simulation. The higher general temperature in the base design can be
attributed to the reduction of windows between models. Note the Reduced High Level
Glazing simulation experiences a large drop in thermal cooling. As is expressed by
Parsons (Parsons, 2011), a reduction in glazing allows for greater reductions in
temperature in the Kitchen Living Dining area of the Villa, and a more prolonged
reduction – maintaining thermal comfort for longer before requiring thermal energy.
This can explain the reduction in cooling energy.
61. Figure 5-1 Base Design Above Ground and Above Ground Resin Change #2 Comparison, Summer Temperature Profile
55
62. Figure 5-2: Base Design Above Ground and Above Ground Resin Change #2 Comparison, Winter Temperature Profile
56
63. ! 57!
5.2 Impact of changes to the building envelope
5.2.1 Floor structure
Testing the floor structure options forms an integral part of the modeling of the
Hadrian Villa. Pidcock prefers an above ground design as it does not involve setting a
concrete floor, which can otherwise increase build time. In testing both models, the
concrete floor performs significantly better than the above ground simulations. We
can verify that the concrete floor simulations hence certainly perform better, as less
thermal energy is required to maintain thermal comfort; the basic concrete slab
simulation has a total thermal load of 30.9MJ/m2
.annum, and the basic above ground
model has a total thermal load of 70.4MJ/m2
.annum. Figures 5-3, 5-4 and 5-5 below
compare the basic design of the concrete floor and above ground simulations
annually. The blue curves indicate the above ground temperature profiles, and red
curves for the concrete floor. The most distinguishable feature between the red and
blue curves is the temperature swing extent. This is directly indicative of the theory
presented by Balaras and Al-Homoud, of the ability of a large thermal mass such as
concrete to control internal temperature swings (Balaras, 1995, Al-Homoud, 2004).
The above ground model uses double the thermal energy, which can be largely
attributed to the lesser amount of thermal mass.
It should be considered however that this is not the only benefit of the grounded
model. The concrete floor simulations are connected to the earth, whereas the above
ground simulations allow for ventilation under the building. This would also lead to a
portion of the excess thermal gains and losses in the building. This would need to be
quantified with a grounded model with no concrete, compared to an above ground
model with the same floor. To this avail, further simulations should also consider that
the earth limits ventilation, and also provides some thermal mass regulation for a
building.
67. ! 61!
5.2.12 Glazing
The final results of both further simulations “… More North Glazing” is to meet an
aesthetic quality of the Hadrian Villa. A large north facing glazing wall allows the
residence of the Hadrian Villa to enjoy natural sunlight in the residence throughout
the year. The simulations indicate that more windows are not a thermally efficient
design (see Figure 5-6 below). However, it is manageable within thermal energy
guidelines, with the implementation of other low energy building techniques (in
previous simulations). An increase of thermal usage by 5.6 MJ/m2
.annum is
approximately a 15% increase – this may be considered insignificant depending on
the residents of the Villa. This is an important consideration for Origination, as it will
also lead to variably higher cost. Note that the cost analysis is outside the scope of this
discussion.
69. ! 63!
!
5.2.3 Fixed louvers
Figure 5-6: Louvers Diagram (Parsons, 2011)
For ease of calculations, the automated louver feature in AccuRate is applied on north
facing lower tier windows of the Hadrian Villa. However, Pidcock suggests use of a
manually adjustable louver system, where summer sun can be blocked out, and winter
sun allowed into the Villa (Figure 5-7). This is modeled in a separate simulation of
with vergolas stretching over the north verandah, having a blocking affect of 100%
from November – February, and no 0% blocking March-October. This simulation is
one of the best performing of the Above Ground simulations. This is reflective of
Datta (2001) and Parsons (2011) that each recommends the addition of a louver to
reduce total heat gain for building with high levels of glazing. The reduction of latent
cooling is indicative of this improvement. As this model more accurately reflects the
type of shading device Pidcock wish to implement on the Hadrian Villa design, it is
certainly applicable to other models, to improve their in thermal energy performance.
70. ! 64!
5.2.4 Thermal mass
One of the clearest results derived from the simulations is the benefit of incorporating
a concrete floor in the Hadrian Villa. When comparing the two streams of
simulations, the concrete floor cases Table 4-1 perform at least 50% to 73% more
thermally efficiently, depending on the simulation. As is highlighted by Gregory et al.
(2007) a building with high levels of glazing will require more thermal mass to reduce
the affects of thermally conductive windows.
5.2.5 Water walls
The internal water walls of the &U Hadrian Villa show a positive impact in thermal
performance, as can be derived from comparisons “Improved Wall Insulation” to
“Half Water Wall”. In this comparison, the amount of water in the wall decreases in
thickness from 1000mm to 500mm, and there is a consequent increase in thermal
energy requirements by 0.8MJ/m2
.annum. Note that this simulation considers an
internal water tank that is “always full”, that is the water level never decreases. The
idea of the water tank in the Hadrian Villa is two-fold – primarily to store useable rain
water, and secondly to provide thermal mass to the building (Parsons, 2011).
Inherently, more water provides more thermal mass. Hence, the water tanks should
have a maintained level of water at near full capacity to have a useful impact on the
thermal performance of the Hadrian Villa.
5.2.6 Phase change material
As is advised by Ecological Design (Caley, 2015), a 100mm concrete layer in the
ceiling is applied to model M51 phase change material. Theoretically, 100mm of
concrete has a thermal conductivity of 0.37W/m.K (Table 3.6, (Cengel, 2002)),.
BioPCM has an approximate thermal conductivity of 0.2W/m.K (PhaseChange
energy solutions Australia P/L, 2015a). Further, phase change material behaves very
differently to a thermal mass considering the change of state before effective thermal
capacitance can be applied. Hence, there are major limitations to this proxy. However,
as AccuRate V1.1.4.1 does not have the ability to factor phase change material, the
71. ! 65!
concrete slab is maintained as the best possible proxy. If further research deemed the
impact testing of phase change material to be more important and requiring detail,
other programs such as EnergyPlus may be utilsed, as is advised by BioPCM
(PhaseChange energy solutions Australia P/L, 2015b).
The concrete proxy applied to the model is fixed in thickness to match the thermal
conductivity of PCM. Hence, any change in this value is purely a theoretical
experiment and not useful to the current design for Pidcock. In modeling a 150mm
concrete ceiling, there is an observed improvement of the thermal load to
30.6MJ/m2
.annum. This indicates that the addition of more thermal mass in a
lightweight structure still has a positive impact. This is an important result as limited
information is presently available on prefabricated structures.
5.2.7 Insulation
The insulation in the &U design has a significant impact on the thermal performance
of the building. As a lightweight pultrusion structure, the &U wall resin is very
thermally conductive. To limit the heat transfer through the walls, insulation is
applied. From the theoretical analysis, it is derived that the resin connector section in
the wall panel has an R-Value of 0.39m2
.K/W. An insulated section however, with
insulation 4.54m2
.K/W, has an overall R-Value of 4.88m2
.K/W. This large difference
improves the thermal performance of the &U panel significantly. This result is also
observed when the beams and columns are insulated. The base design has a total
thermal load of 70.4MJ/m2
.annum. When the beams and columns are insulated with
50mm of PIR insulation (2.31m2
.K/W), the thermal load decrease to
65.3MJ/m2
.annum. While this is not a significant reduction in thermal load, some data
is collected. Of the 5.1MJ/m2
.annum reduction, 4.5MJ/m2
.annum are reduced from
the cooling load. Furthermore, of the total area of the wall, the beam and columns
constitute only 15-32% (depending on the face). Hence, the beam and column
insulation has a small impact to the thermal energy requirement of the Hadrian Villa.
As Al-Homoud (2004) and Parsons (2011) discuss, the reduction in thermal energy
demand is due to the ability of the insulation to reduce thermal gains and losses. In
our modeling, it limits heat leaving the building and hence the heating load reduces.
