The document discusses methods for estimating the heat demand in buildings. It covers topics such as the energy situation in buildings, physical principles of heat and moisture transfer, energy balances, and calculation methods. Specifically, it provides information on the energy consumption and fuels used for space heating in Germany. It also discusses categories of buildings based on their heat demand and regulations in Germany that establish limits on energy demand and methods for calculating a building's energy demand.
Ms Neeta Sharma, MD, IAPMO India, gave presentation on water conservation and water efficient products in India at CII-IGBC 15th Green Building Congress 2017 event at Jaipur
Seismic Retrofitting of Masonry StructuresDr K M SONI
Large number of masonry buildings are susceptible to damages during earthquakes due to no provisions of features of seismic requirements. Such features can be included during seismic retrofitting to increase resistance of buildings to earthquakes.
Applications of Artificial Neural Networks in Civil EngineeringPramey Zode
An artificial brain-like network based on certain mathematical algorithms developed using a numerical computing environment is called as an ‘Artificial Neural Network (ANN)’. Many civil engineering problems which need understanding of physical processes are found to be time consuming and inaccurate to evaluate using conventional approaches. In this regard, many ANNs have been seen as a reliable and practical alternative to solve such problems. Literature review reveals that ANNs have already being used in solving numerous civil engineering problems. This study explains some cases where ANNs have been used and its future scope is also discussed.
Ms Neeta Sharma, MD, IAPMO India, gave presentation on water conservation and water efficient products in India at CII-IGBC 15th Green Building Congress 2017 event at Jaipur
Seismic Retrofitting of Masonry StructuresDr K M SONI
Large number of masonry buildings are susceptible to damages during earthquakes due to no provisions of features of seismic requirements. Such features can be included during seismic retrofitting to increase resistance of buildings to earthquakes.
Applications of Artificial Neural Networks in Civil EngineeringPramey Zode
An artificial brain-like network based on certain mathematical algorithms developed using a numerical computing environment is called as an ‘Artificial Neural Network (ANN)’. Many civil engineering problems which need understanding of physical processes are found to be time consuming and inaccurate to evaluate using conventional approaches. In this regard, many ANNs have been seen as a reliable and practical alternative to solve such problems. Literature review reveals that ANNs have already being used in solving numerous civil engineering problems. This study explains some cases where ANNs have been used and its future scope is also discussed.
It is the presentation based on pre- stressed concrete construction which includes each and every point and scope which may be useful to civil engineering students
For more relevant materials visit
electro-voyage.blogspot.com
In this slide, we will see how to approach the basic lighting system both manually and using software
We will have to solve a few examples and design the lighting system manually by applying the various formula of the Lumen Method.
Introduction
What is zero energy building?
Why zero energy building?
How to adopt zero energy?
Advantage
Disadvantage
Zero energy buildings in India
Zero energy building versus green building
Green Building Site Selection and Development is equally important as the Construction of Building itself. Let's discover ways to conserve from the first step.
Guide for homeowners on how to use green home design, sustainable building materials and green building techniques for energy efficient new home construction.
SUSTAINABLE, ENERGY EFFICIENT BUILDING MATERIALS AND TECHNOLOGIESSamanth kumar
SUSTAINABLE, ENERGY EFFICIENT BUILDING MATERIALS AND TECHNOLOGIES, M.ARCH (ENVIRONMENTAL ARCHITECTURE) ANNA UNIVERSITY SECOND SEMESTEREnergy Efficient Construction Technology
➔ Filler Slab
➔ Rat trap Bond
➔ Technologies developed by CBRI
➔ Traditional Building Construction Technologies
➔ Concept of Resource rescue,
➔ Concept of Recycled content,
➔ Concept of Regional materials,
➔ Energy Efficiency
➔ Energy Conservation
➔ Recourse Consumption
➔ Distribution of Energy use in India
➔ Factors affecting the Energy use in Buildings
➔ Pre Building Stage, Construction Stage & Post Occupancy stages
➔ Concept of Embodied Energy
➔ Energy needs in Production of Materials
➔ Transportation Energy
➔ Concept of light footprint on Environment
amount of energy used is equal to amount of renewable energy created on the site
reduce carbon emissions & reduce dependence on fossil fuels
Buildings that produce a surplus of energy over the year are called “Energy Surplus Buildings”
During the last 20 years more than 200 reputable projects claiming net zero energy balance have been realized all over the world.
NZEB buildings consequently contribute less overall greenhouse gas to the atmosphere than similar non-ZNE buildings. They do at times consume non-renewable energy and produce greenhouse gases, but at other times reduce energy consumption and greenhouse gas production elsewhere by the same amount. Traditional buildings consume 40% of the total fossil fuel energy in all over the world and are significant contributors of greenhouse gases.
This was the major media asset for one of the lessons for the Installer Math Module for Weatherization training. To preserve formatting, the slides are from JPEG, so you won't be able to see the animations.
It is the presentation based on pre- stressed concrete construction which includes each and every point and scope which may be useful to civil engineering students
For more relevant materials visit
electro-voyage.blogspot.com
In this slide, we will see how to approach the basic lighting system both manually and using software
We will have to solve a few examples and design the lighting system manually by applying the various formula of the Lumen Method.
Introduction
What is zero energy building?
Why zero energy building?
How to adopt zero energy?
Advantage
Disadvantage
Zero energy buildings in India
Zero energy building versus green building
Green Building Site Selection and Development is equally important as the Construction of Building itself. Let's discover ways to conserve from the first step.
Guide for homeowners on how to use green home design, sustainable building materials and green building techniques for energy efficient new home construction.
SUSTAINABLE, ENERGY EFFICIENT BUILDING MATERIALS AND TECHNOLOGIESSamanth kumar
SUSTAINABLE, ENERGY EFFICIENT BUILDING MATERIALS AND TECHNOLOGIES, M.ARCH (ENVIRONMENTAL ARCHITECTURE) ANNA UNIVERSITY SECOND SEMESTEREnergy Efficient Construction Technology
➔ Filler Slab
➔ Rat trap Bond
➔ Technologies developed by CBRI
➔ Traditional Building Construction Technologies
➔ Concept of Resource rescue,
➔ Concept of Recycled content,
➔ Concept of Regional materials,
➔ Energy Efficiency
➔ Energy Conservation
➔ Recourse Consumption
➔ Distribution of Energy use in India
➔ Factors affecting the Energy use in Buildings
➔ Pre Building Stage, Construction Stage & Post Occupancy stages
➔ Concept of Embodied Energy
➔ Energy needs in Production of Materials
➔ Transportation Energy
➔ Concept of light footprint on Environment
amount of energy used is equal to amount of renewable energy created on the site
reduce carbon emissions & reduce dependence on fossil fuels
Buildings that produce a surplus of energy over the year are called “Energy Surplus Buildings”
During the last 20 years more than 200 reputable projects claiming net zero energy balance have been realized all over the world.
NZEB buildings consequently contribute less overall greenhouse gas to the atmosphere than similar non-ZNE buildings. They do at times consume non-renewable energy and produce greenhouse gases, but at other times reduce energy consumption and greenhouse gas production elsewhere by the same amount. Traditional buildings consume 40% of the total fossil fuel energy in all over the world and are significant contributors of greenhouse gases.
This was the major media asset for one of the lessons for the Installer Math Module for Weatherization training. To preserve formatting, the slides are from JPEG, so you won't be able to see the animations.
The analysis of energy savings of vacuum insulated glass apr2015Jill Ku
Comparisons of single glazing vs. low-e insulating glazing vs. low-e vacuum insulated glass, in terms of energy consumptions of HVAC of an office building
Thermal Potential in the Built EnvironmentYale Carden
HVAC systems have traditionally used the local ambient air (heating and cooling) or fossil fuels (predominantly heating through combustion) as their heat source and heat sink. Thermal storage is still a relatively new application and typically requires large volumes of water or ice.
This paper explores the available thermal potential within the built environment and how the utilisation of this thermal potential can provide efficient heating, cooling and hot water as well as thermal storage. In some instances, this may be the local ambient air, less likely it will be fossil fuels.
More likely, it includes the thermal potential within the ground, water bodies and infrastructure such as subways, water, sewer, building foundations and other buildings as well as artificial thermal storage such as phase change materials.
The key is to identify the optimal thermal sources, sinks and storages for a given building at a given location and climate. Then, an integrated approach using optimised control strategies, including predictive capabilities, will enable a building to access these various thermal sources at the thermally optimal time to provide significant energy savings and enhanced operation.
Such an integrated approach also maximises the availability of on-site renewable power generation, further increasing energy savings, decreasing the typical cooling peak demand and increasing energy productivity.
The goal of this discussion is to demystify building performance modeling. Computer-simulations give you a more complete picture of how various context and design factors can affect the performance of your space. Modeling information can help you analyze the impacts of your design decisions and determine how to most effectively meet project goals.
Energy modeling is also valuable tool used for code compliance and LEED points. Not to mention the fancy graphics that models produce to show your clientele your commitment to performance-based design.
This discussion will present various opportunities that can arise from building performance simulations with analysis at the early design, whole building, and building component levels. We will examine the following types of analysis:
• Climate
• Daylighting
• Massing and orientation
• Whole building energy usage forecast
• Fenestration design
• Façade development
• Zone level energy performance
• Baseline and design case models
• System selection and optimization
For more information on this training, contact Brittany Grech at bgrech@yrgsustainability.com or (347) 843-3085.
The presentation will include the following topics:
- Fundamentals of energy modeling
- Overview of the eQUEST energy modeling program
- Recommendations for integrating energy modeling into the design process
- Brief description of baseline energy modeling using ASHRAE Appendix G
- Recommended strategies for reducing energy use
- How to review energy modeling results
-Common problems and how to avoid them
The Building Science of Thermal ComfortBronwyn Barry
An incomplete review of thermal comfort, thermodynamics, indoor air quality, who influenced this science and how it is being used to design insanely comfortable buildings. Bonus side benefit: they happen to use very little energy. (Don't tell anyone about this - it may be too radical.)
Lectures on Heat Transfer - Introduction - Applications - Fundamentals - Gove...tmuliya
This file contains Introduction to Heat Transfer and Fundamental laws governing heat transfer.
The slides were prepared while teaching Heat Transfer course to the M.Tech. students in Mechanical Engineering Dept. of St. Joseph Engineering College, Vamanjoor, Mangalore, India.
The present study focuses on the development of software (general mathematical optimization model) which has the following characteristics:
• It will be able to find the optimal combination of installed equipment (power & heat generation etc) in a Shopping Mall (micro-grid)
• With multi-objective to maximize the cost at the same time as minimizing the environmental impacts (i.e. CO2 emissions).
• To date, this tool is scarce to the industry (similar to DER-CAM, Homer).
System Layout and Applications
Low Mass vs High Mass
Radiant Panels
Fan Coils
Domestic Hot Water
Solar Thermal
Balance Point Strategies
Heat Pump Application Software
Mono-Valent
Mono-Energetic
Bi-Valent
Programming for Energy Savings with User Interface
My part of the joint session on Passive House—what it is and why it matters—with Stephan Tanner at the 2009 Minnesota AIA Convention.
The slideshow contains a lot of full-screen images but no subtitles, therefore omitting some of the information which would have been given verbally during the presentation.
2011 Passive House Conference, Synergy Case StudyTE Studio
High-performance is inherently linked to higher first-day cost. Most assume that it only exists at the top of the market. Affordability is often confused with cheap upfront cost. The two present a seemingly irreconcilable conundrum.
TE Studio’s approach defines affordability as something that is financially sustainable over a given period of time. Within this paradigm, first-day costs become a line item on a laundry list of lifecycle cost an owner is typically faced with. The Synergy case study aims to clarify the difference between first-day cost and total cost of ownership, thus redefining affordability and the impact of high-performance design on sustainable and financially viable structures in cold climates (Climate Zone 6).
Synergy is a highly energy efficient, durable and flexible compact home designed as a conversation starter which aims to make high performance accessible to a broad section of owners and developers. Entirely designed without client input and in our free time, Synergy is TE Studio’s testbed for affordability as well as high-performance assemblies and systems. Synergy has not been built but is currently being considered by different entities for projects in 2012.
The slideshow contains a lot of full-screen images but no subtitles, therefore omitting some of the information which would have been given verbally during the presentation.
With a new combination of existing technologies, we believe it is possible to create a renewable energy source –ultra deep EGS (Enhanced Geothermal Systems)– which is cheaper than coal.
The principle is simple: a higher temperature results in a better electricity conversion efficiency. So there is a double effect: a better conversion efficiency and the amount of available energy is higher. This double effect is stronger than the related cost of ultra deep drilling. Simple calculations demonstrate that ‘deeper is cheaper’.
STATE OF THE INDUSTRY KEYNOTE BNEF SUMMIT 2016Tuong Do
MICHAEL LIEBREICH, CHAIRMAN OF THE ADVISORY BOARD, BLOOMBERG NEW ENERGY
FINANCE: Thank you very much and (INAUDIBLE) how quickly a year goes. What I'm trying to do is I'm
trying to live up to that idea of living in the present and also looking at the future.
Renewable energy models for rice residues - SNV VietnamTuong Do
Renewable energy models for rice residues - Potentials for Green Growth and Experience through SSC project by SNV
Presented at the Forum
Green growth in Agriculture:
Potentials, Experience and Recommendations
Hanoi, 31st October 2014
GIZ support mechanism for RE development in VietnamTuong Do
Hanoi, 19/09/2014
Ingmar Stelter, Program Manager
Werner Kossmann, Chief Technical Advisor
GIZ Viet Nam Energy Support Program
Energy Sector Development Partners Coordination
Module 1: Technical options and international best practices for on-grid powe...Tuong Do
Module 1: Technical options and international best practices for on-grid power generation from biomass, biogas and waste-to-energy (Training on "On-Grid Applications of Biomass, Biogas and Waste-to-Energy Power Plants for " in HN on December 10-12, 2013)
Module 2: Assessment of international good practices in the fields of biomass...Tuong Do
Module 2: Assessment of international good practices in the fields of biomass energy technology ...(Training on "On-Grid Applications of Biomass, Biogas and Waste-to-Energy Power Plants for " in HN on December 10-12, 2013)
Module 3: Criteria for the siting and systems integrationTuong Do
Module 3: Criteria for the siting and systems integration... (Training on "On-Grid Applications of Biomass, Biogas and Waste-to-Energy Power Plants for " in HN on December 10-12, 2013)
Module 7: Assessment of framework conditions and necessary adaptationsTuong Do
Module 7: Assessment of framework conditions and necessary adaptations (Training on "On-Grid Applications of Biomass, Biogas and Waste-to-Energy Power Plants for " in HN on December 10-12, 2013)
Module 4: Basic design parameters (technical and economic) for commercially v...Tuong Do
Module 4: Basic design parameters (technical and economic) for commercially viable on-grid biomass combustion heat and power plants (Training on "On-Grid Applications of Biomass, Biogas and Waste-to-Energy Power Plants for " in HN on December 10-12, 2013)
Module 6 Basic design parameters for commercially viable on-grid biomass gasi...Tuong Do
Module 6: Basic design parameters for commercially viable on-grid biomass gasification heat and power plants (Training on "On-Grid Applications of Biomass, Biogas and Waste-to-Energy Power Plants for " in HN on December 10-12, 2013)
Elevating Tactical DDD Patterns Through Object CalisthenicsDorra BARTAGUIZ
After immersing yourself in the blue book and its red counterpart, attending DDD-focused conferences, and applying tactical patterns, you're left with a crucial question: How do I ensure my design is effective? Tactical patterns within Domain-Driven Design (DDD) serve as guiding principles for creating clear and manageable domain models. However, achieving success with these patterns requires additional guidance. Interestingly, we've observed that a set of constraints initially designed for training purposes remarkably aligns with effective pattern implementation, offering a more ‘mechanical’ approach. Let's explore together how Object Calisthenics can elevate the design of your tactical DDD patterns, offering concrete help for those venturing into DDD for the first time!
Securing your Kubernetes cluster_ a step-by-step guide to success !KatiaHIMEUR1
Today, after several years of existence, an extremely active community and an ultra-dynamic ecosystem, Kubernetes has established itself as the de facto standard in container orchestration. Thanks to a wide range of managed services, it has never been so easy to set up a ready-to-use Kubernetes cluster.
However, this ease of use means that the subject of security in Kubernetes is often left for later, or even neglected. This exposes companies to significant risks.
In this talk, I'll show you step-by-step how to secure your Kubernetes cluster for greater peace of mind and reliability.
Essentials of Automations: Optimizing FME Workflows with ParametersSafe Software
Are you looking to streamline your workflows and boost your projects’ efficiency? Do you find yourself searching for ways to add flexibility and control over your FME workflows? If so, you’re in the right place.
Join us for an insightful dive into the world of FME parameters, a critical element in optimizing workflow efficiency. This webinar marks the beginning of our three-part “Essentials of Automation” series. This first webinar is designed to equip you with the knowledge and skills to utilize parameters effectively: enhancing the flexibility, maintainability, and user control of your FME projects.
Here’s what you’ll gain:
- Essentials of FME Parameters: Understand the pivotal role of parameters, including Reader/Writer, Transformer, User, and FME Flow categories. Discover how they are the key to unlocking automation and optimization within your workflows.
- Practical Applications in FME Form: Delve into key user parameter types including choice, connections, and file URLs. Allow users to control how a workflow runs, making your workflows more reusable. Learn to import values and deliver the best user experience for your workflows while enhancing accuracy.
- Optimization Strategies in FME Flow: Explore the creation and strategic deployment of parameters in FME Flow, including the use of deployment and geometry parameters, to maximize workflow efficiency.
- Pro Tips for Success: Gain insights on parameterizing connections and leveraging new features like Conditional Visibility for clarity and simplicity.
We’ll wrap up with a glimpse into future webinars, followed by a Q&A session to address your specific questions surrounding this topic.
Don’t miss this opportunity to elevate your FME expertise and drive your projects to new heights of efficiency.
Smart TV Buyer Insights Survey 2024 by 91mobiles.pdf91mobiles
91mobiles recently conducted a Smart TV Buyer Insights Survey in which we asked over 3,000 respondents about the TV they own, aspects they look at on a new TV, and their TV buying preferences.
Accelerate your Kubernetes clusters with Varnish CachingThijs Feryn
A presentation about the usage and availability of Varnish on Kubernetes. This talk explores the capabilities of Varnish caching and shows how to use the Varnish Helm chart to deploy it to Kubernetes.
This presentation was delivered at K8SUG Singapore. See https://feryn.eu/presentations/accelerate-your-kubernetes-clusters-with-varnish-caching-k8sug-singapore-28-2024 for more details.
Key Trends Shaping the Future of Infrastructure.pdfCheryl Hung
Keynote at DIGIT West Expo, Glasgow on 29 May 2024.
Cheryl Hung, ochery.com
Sr Director, Infrastructure Ecosystem, Arm.
The key trends across hardware, cloud and open-source; exploring how these areas are likely to mature and develop over the short and long-term, and then considering how organisations can position themselves to adapt and thrive.
2. CONTENTS
• INTRODUCTION
– ENERGY SITUATION IN BUILDING SECTOR
• PHYSICAL PRINCIPLES
– HEAT TRANSFER
– MOISTURE TRANSFER
• ENERGY BALANCES
– STEADY STATE BEHAVIOR
– DYNAMIC BEHAVIOR - THERMAL INERTIA
• CALCULATION METHODS
– MONTHLY METHOD
– SIMPLIFIED METHOD
05.05.2011 SS 10/11 2
3. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
ENERGY SITUATION
• ENERGY CONSUMPTION IN
GERMANY Lighting,
Domestic 5%
Energy consumption by sectors (Germany) hot water
demand,
13%
Industry, 27%
Space
heating,
81%
Households,
Transport, 28% 45% Source: VDEW-Materialien: Endenergieverbrauch in Deutschland, 2002
05.05.2011 SS 10/11 3
4. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
ENERGY SITUATION
• FUELS USED IN GERMANY TO SUPPLY THE SPACE HEATING
DEMAND
Electricity 4%
Others 8%
Renewables are
here!
Distric heating 7%
Natural gas 43%
Carbon 2%
Gasoil 36%
Source: VDEW-Materialien: Endenergieverbrauch in Deutschland, 2002
05.05.2011 SS 10/11 4
5. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
ENERGY SITUATION
IN GERMANY EnEV - “Energie-einsparverordnung”:
– Limits the maximal energy demand for buildings according
to their constructive details
– Establishes a calculation method for the energy demand of
a building -> basis for comparison
– Defines different building “categories” according to their
energy consumption
05.05.2011 SS 10/11 5
6. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
ENERGY SITUATION
05.05.2011 SS 10/11 6
8. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
ENERGY SITUATION
RENEWABLE ENERGY HEAT STANDARD
“EEWärmegesetz”:
– Approved July08 ->
Jan 09
– Application to new
buildings
• Biogas 30%
• Solar: 15%, 0.03-0.04m2coll/m2living area
• Others (biofuels, wood, geothermal or environmental heat) 50%
05.05.2011 SS 10/11 8
9. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
GENERAL BALANCES
ENERGY BALANCE IN A TYPICAL BUILDING
100%
Transmission Biggest energy saving
Internal gains potential!!!
losses 80%
Ventilation
losses 60%
40%
20%
Solar heat Heat supplied
gains by heating 0%
system Cold bridges %
Ventilation losses %
Transmission losses %
05.05.2011 SS 10/11 9
10. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
GENERAL BALANCES
• BUILDING ENVELOPE: Heat losses can amount up to 75%
of total heat losses
External walls
20% Roof 19% Moving to energy
efficient buildings…
Floor to crawl
space 9%
BASIC USED
SOLUTION: Reduction
of the major heat losses
Windows
52% using better materials in
Percentage of heat losses through different the building envelope
constructive parts of the envelope
05.05.2011 SS 10/11 10
11. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
HEAT TRANSFER
• CONDUCTION
Tin
d layer [m2K/W]
Rlayer =
λlayerl Tout
Rwall = ∑ Rlayer [m2K/W]
λmaterial [W/mK]
1 1 dmaterial [m]
U wall = = [W/m2K]
dlayer
Rwall
∑λ T
layer
QT , wall = U wall ⋅ Awall ⋅ (Tin − Tout )
05.05.2011 SS 10/11 11
12. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
HEAT TRANSFER
TRANSMISSION LOSSES: Conduction + convection
1 1
U wall = = [W/m2K]
Rwall 1 d layer 1
+∑ +
hi λlayer he Superficial heat transmission coefficient: [0 -
100 W/m2K]
T
• Floor to unheated basement • Roof under winter conditions!
• Roof in summer conditions
05.05.2011 SS 10/11 12
13. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
HEAT TRANSFER
THERMAL BRIDGES
• DEFINITION: Places on the envelope where, during the heating
period, higher heat flows and lower inner surface temperatures
occur.
• CAUSES:
Material caused thermal bridge Geometric thermal bridge
Source: Maas
05.05.2011 SS 10/11 13
14. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
HEAT TRANSFER
THERMAL BRIDGES
• CHARACTERISATION: Ψ = Coefficient of losses through
thermal bridge, [W/mK]
f = (superficial) Temperature factor , [-]
Θsi= surface temperature inside wall
Source: Maas Θe = exterior temperature
Θi = indoor temperature
f=0 -> exterior temperature
f=1 -> indoor air temperature
05.05.2011 SS 10/11 14
15. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
HEAT TRANSFER
THERMAL BRIDGES
Source: Maas
05.05.2011 SS 10/11 15
16. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
HEAT TRANSFER
THERMAL BRIDGES
Source: Maas
05.05.2011 SS 10/11 16
17. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
HEAT TRANSFER
VENTILATION (CONVECTION) LOSSES
05.05.2011 SS 10/11 17
18. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
HEAT TRANSFER
VENTILATION LOSSES
• Definition: Energy losses due to the exchange of an air flow
between the building and the surroundings
• Characterization: measured in h-1 = represents the portion of
the total (heated) building volume exchanged in one hour
• Causes:
– Air leakages in the building envelope: constructive
problem / solution
– Health and Safety reasons: necessary to allow pollutants
leave the living space
According to building typology (residential, office buildings,
hospitals…) minimum air exchange rates have to be assured
05.05.2011 SS 10/11 18
19. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
HEAT TRANSFER
VENTILATION LOSSES
Air exchange
Tight envelope (n50<3h-1)
Untight envelope (n50> 5h-1)
Regulable Ventilation units
Window open up without cross ventilation
Window open up with cross ventilation
Window open without cross ventilation
Window open with cross ventilation
Source: Recknagel
05.05.2011 SS 10/11 19
20. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
HEAT TRANSFER
VENTILATION LOSSES
TYPICAL VALUES for a non efficient old building: 1,5 – 2 h-1 or even
higher (through air leakages in envelope)
According to EnEV (Energieeinsparverordnung) in Germany:
Non efficient Efficient (proven tight) Efficient building
building building without with mechanical
mechanical ventilation ventilation system
system
Values allowed Air leakages: 0,7 Air leakages: 0,6 Mech.vent.: 0,4
in EnEV, h-1 Air leakages: 0,2
05.05.2011 SS 10/11 20
21. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
MOISTURE TRANSFER
1 - 2 liters/day person
• Transport mechanisms:
2 people house: – DIFFUSION
ca. 2liters/day – CONVECTION
person
(ventilation)
– (SORPTION)
4 people house:
ca. 4liters/day
person
Source: Maas
05.05.2011 SS 10/11 21
22. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
Maximal water content in air MOISTURE TRANSFER
10°C
9.4g
7.9g
Air temperature
Source: Maas
05.05.2011 SS 10/11 22
23. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
CARRIER (MOLIERE) DIAGRAM
05.05.2011 SS 10/11 23
24. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
CARRIER (MOLIERE) DIAGRAM
1.- 100%RH, 20°C,14.5g/kg
2.- 100%RH, 10°C,7.5g/kg
3.- 70%RH, 20°C, 7g/kg
4.- 85%RH,17°C, 7g/kg
Air density ≈ 1.2kg/m3
Dew point temperature
05.05.2011 SS 10/11 24
25. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
MOISTURE TRANSFER
Rel. humidity
Air temperature
Dew point temperature
Dew point temperature
Rel. humidity
Source: Maas Air temperature
05.05.2011 SS 10/11 25
26. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
MOISTURE TRANSFER
SUPERFICIAL TEMPERATURE
THERMAL BRIDGES
Outdoor air temp. -15°C
Surface
temperatures
Max. relative
humidity
Indoor air temp. 20°C
70%RH
External wall - corner
05.05.2011 SS 10/11 26
27. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
MOISTURE TRANSFER
MOLD GROWTH
05.05.2011 SS 10/11 27
28. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
MOISTURE TRANSFER
MOLD GROWTH
HUMIDITY TEMPERATURE
Probability of growth
Probability of growth
Relative humidity, % Surf. temperature, °C
Source: Maas
05.05.2011 SS 10/11 28
29. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
MOISTURE TRANSFER
WATER CONDENSATION
Rel.
Humidity
MOLD GROWTH
Source: Maas
05.05.2011 SS 10/11 29
30. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
MOISTURE TRANSFER
EXAMPLE
Mold growth is more restrictive condition Rel.
Humidity
Source: Maas
05.05.2011 SS 10/11 30
31. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
MOISTURE TRANSFER
DIFFUSION
Source: Maas
Description Unit Description Unit
Temperature Partial vapor pressure
Heat transm. Coeff. Material transm. Coeff.
Heat conductivity Vapor diffusivity
Thermal resistance Resistance to vapor
diffusion
Heat flow Vapor diffussion flow
05.05.2011 SS 10/11 31
32. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
MOISTURE TRANSFER
DIFFUSION
Air Bitumen
Metal
Insulation
d air
Concrete
Z air δ air δ air
μ= = =
Z material d material δ material
[-] δmaterial
dmaterial=dair Source: Maas
05.05.2011 SS 10/11 32
33. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
MOISTURE TRANSFER
g
DIFFUSION - EXAMPLE
Material μ
Concrete 70-150
1086
Insulation g = 0.421 g/m2h
Kork 5-10
PU foams 30-100
Alu-foil Tight
472
(100000000) 281
Wood 40 (50/400)
Source: Maas
[m h Pa / kg]
05.05.2011 SS 10/11 33
34. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
MOISTURE TRANSFER
CONVECTION - EXAMPLE
Source: Maas
05.05.2011 SS 10/11 34
35. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
MOISTURE TRANSFER
CONVECTION - EXAMPLE
Vh,buil=50m3 ; n=0.8 h-1 Ps = 1170 Pa
Vvent=40m3/h (=Vh,buil*n) R = 462 J/kgK
Ti=20°C, RH=50% Ps = 139 Pa
Te=-10°C, RH=80%
and
-10°C and 1.15
263.15
1.15 304.3
Source: Maas
05.05.2011 SS 10/11 35
36. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
MOISTURE TRANSFER
COMPARISON
CONVECTION - DIFFUSION
g
Aint,walls=22.5 m2 g = 0.421 g/m2h
n = 0.8 h-1
Outside: 80% RH, -10°C
304.3 g/h 9.47 g/h
Inside: 50% RH, 20°C
Source: Maas
05.05.2011 SS 10/11 36
37. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
MOISTURE TRANSFER
CONVECTION:
Air exchange
Required air exchange Rel. humidity
Humidity production
Source: Maas
05.05.2011 SS 10/11 37
38. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
ENERGY BALANCES
STEADY STATE
Transmission Internal gains
losses
Ventilation
QT losses
Qv
Solar heat In order to keep
gains Heat supplied
by heating the room temperature
system
at a constant acceptable value
Energy Supplied = Heat Losses - Energy Gains
“Active gains” “Passive gains”
05.05.2011 SS 10/11 38
39. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
THERMAL LOSSES
TRANSMISSION LOSSES env,i = walls, floor, roof,
windows
QT ,env = ΣU env,i ⋅ Aenv,i ⋅ (Tin − Tout ) [W]
(separately for each of them)
– INCLUDING THERMAL BRIDGES
H T ,building = ΣU env ,i ⋅ Aenv ,i + ΔU tb ⋅ Aenvelope [W/K]
– TOTAL TRANSMISSION LOSSES
QT ,buil = (ΣU env,i ⋅ Aenv,i + ΔU tb ⋅ Aenv ) ⋅ (Tin − Tout ) [W]
05.05.2011 SS 10/11 39
40. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
THERMAL LOSSES
VENTILATION LOSSES
n = air exchange rate [h-1]
H V = Vh,buil ⋅ 0.34 ⋅ n [W/K]
HEATED Heat
volume of the capacity of
air [Wh/m3K]
building [m3]
QV = H V ⋅ (Tin − Tout )
According to the German regulation EnEV, can
be simplified:
Vh ,buil = Vbrutto ⋅ 0.76
05.05.2011 SS 10/11 40
41. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
THERMAL LOSSES
TOTAL LOSSES (TRANSMISSION+VENTILATION)
– Transmission Losses
QT ,buil = (ΣU env,i ⋅ Aenv,i + ΔU tb ⋅ Aenv ) ⋅ (Tin − Tout ) =HT ⋅ (Tin − Tout ) [W]
– Ventilation Losses
QV = H V ⋅ (Tin − Tout ) [W]
– Total Losses
Qlosses = ( H T + H V ) ⋅ (Tin − Tout ) [W]
05.05.2011 SS 10/11 41
42. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
THERMAL LOSSES + GAINS
WINDOWS
– Upane = 3 – 0.6 [W/m2K]
-> great influence on heat
demand
– SHGC, g = 0.5 – 0.8 [-]
-> great influence on
cooling demand
– ε = 0.84
– εlow = 0.2 !!!
05.05.2011 SS 10/11 42
43. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
ENERGY - DYNAMIC
ENERGY BALANCE - DYNAMIC BEHAVIOR
Transmission Internal gains
losses
Ventilation
QT losses
Qv
Solar heat
gains Heat supplied
by heating
system
Energy Supplied = Heat Losses - Energy Gains +- Energy Stored
05.05.2011 SS 10/11 43
44. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
5000
4000
Specific heat capacity ENERGY - DYNAMIC
THERMAL MASS
c [J/kgK]
3000
2000
1000
0
Aluminium
Foam glass
Glass
Brick
Wood
Sand
Concrete
Water
insulation
Mineral
3000
density
2500
2000
rho [kg/m3]
Csto = ci ⋅ ρ i ⋅ Ai ⋅ d i 1500
1000
500
0
Aluminium
Glass
Brick
Sand
Concrete
Foam glass
Wood
Water
insulation
Mineral
Source: Wikipedia
05.05.2011 SS 10/11 44
45. lambda [W/mK]
0
1
2
3
4
5
Wood
Glass
05.05.2011
INTRODUCTION
Source: Wikipedia
Mineral
insulation
Foam glass
THERMAL MASS
Sand
Brick
PHYS. PPLES.
237
Aluminium
c [J/kgK]
Concrete
0
1000
2000
3000
4000
5000
rho [kg/m3]
Water
0
500
1000
1500
2000
2500
3000
Wood
SS 10/11
Wood
Glass
Glass
Mineral
insulation
Mineral
insulation
Foam glass
ENERGY BALANCES
Foam glass
Sand
Sand
Brick
Brick
Aluminium
Aluminium
Concrete Concrete
45
THERMAL MASS
Water Water
CALC. METHODS
46. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
Specific heat capacity ENERGY - DYNAMIC
THERMAL MASS
Concrete Insulation
Temperature
Temperature
Thickness
05.05.2011 SS 10/11 46
Source: Maas
47. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
Specific heat capacity ENERGY - DYNAMIC
U-Value Mass THERMAL MASS
[W/m2K] [kg/m2]
6cm
Outdoor Temperature
40cm
Energy flow
43.5cm
Solar radiation
26cm
Time of day
Outdoor Temperature
radiation
Solar
05.05.2011 SS 10/11 47
Source: Maas
48. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
TOTAL LOSSES (TRANSMISSION+VENTILATION)
– Transmission Losses
QT ,buil = (ΣU env,i ⋅ Aenv,i + ΔU tb ⋅ Aenv ) ⋅ (Tin − Tout ) =H T ⋅ (Tin − Tout ) [W]
– Ventilation Losses
QV = H V ⋅ (Tin − Tout ) [W] For which time-step
Depends on the
data we have for the
do we apply this
equation?
outdoor
– Total Losses temperature…
Qlosses = ( H T + H V ) ⋅ (Tin − Tout ) [W]
Tin is the indoor desired temperature: regarded as a CONSTANT value,
typically set between 19 and 21°C for the heating period.
05.05.2011 SS 10/11 48
49. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
MONTHLY METHOD
TOTAL LOSSES
Q losses = Σ ( H T + H V ) ⋅ (Tin − Tout ) ⋅ t M ⋅ 24 [Wh/a]
months
• Tout represents MONTHLY mean values
• tM represents the number of days of the month considered
05.05.2011 SS 10/11 49
50. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
MONTHLY METHOD
SOLAR HEAT GAINS
QSolar , windows = Σ Awindows ⋅ g i ⋅ FF ⋅ Fs ⋅ Gwindow [Wh/a]
months
• gi represents the energy
transmissivity of the window glass;
typically is around 0.6
• FF represents the % of glass against frame in the window
area; typically is around 0.7
• Fs represents the % of shadowing over the glass
• Gwindow represents the incident solar radiation onto the
window, in Wh/m2
05.05.2011 SS 10/11 50
51. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
THERMAL LOSSES + GAINS
WINDOWS, 52% of total losses:
Does not require
1. Avoid heat losses -> Better insulation materials:
much more planning
- Uw= 3 - 0.6 W/m2K
Three pane window
Single or two
effort.
filled with Ar/Kr
pane window
Typ. In efficient houses
2. Increase solar heat gains -> Orientation
- Highest solar irradiation on the south façade,
Requires integral planning of
high potential for solar heat gains -> maximize
glazed surface facing south
the building integrated into
- North façade receives very few solar
its environment for solar gains and
irradiation, low potential
high heat losses through windows -> minimize
Typ. Approach passive houses
glazed surfaces Yearly variation of solar
path in the sky
05.05.2011 SS 10/11 51
52. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
MONTHLY METHOD
INTERNAL HEAT GAINS
• Internal heat gains depend on the use pattern of the building:
office, hospital, residential…
• For residential buildings: constant hourly value of 5 W/m2, per m2
useful area in the building
Qint_ gains = Σ 5 ⋅ AN ⋅ 24 ⋅ tM [Wh/a]
months
05.05.2011 SS 10/11 52
53. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
MONTHLY METHOD
ENERGY DEMAND
– Simplification:
Qh = Qlosses − QSolar , windows − Qint_ gains [Wh/a]
– Actually, not all energy gains can be “used”:
Qh = Qlosses − η (QSolar , windows + Qint_ gains ) [Wh/a]
• η depends on the heat storage capacity of the building structure
and its materials, which is a function of ρ [kg/m3], c [Wh/kgK], d [m],
A [m2] of the material:
Csto = ci ⋅ ρ i ⋅ Ai ⋅ d i [W/K]
05.05.2011 SS 10/11 53
54. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
MONTHLY METHOD
ENERGY DEMAND
– Types of building constructions according to its heat
capacity
• LIGHT
– Csto/A < 50 Wh/m2K
• HEAVY
– Csto/A > 130 Wh/m2K
Qh = Qlosses − η (QSolar , windows + Qint_ gains ) [Wh/a]
– η = 0.9 for light buildings [-]
– η = 0.95 for heavy buildings [-]
05.05.2011 SS 10/11 54
55. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
MONTHLY METHOD
ENERGY DEMAND
– BUILDING WITH ZONES AT DIFFERENT
TEMPERATURES:
• German Norm: gives correction factors, Fx, that have to be applied
to obtain the HT corrected of the building
Building part Fx [-]
Outside wall, window, roof, floor 1
H T = ΣU wall ⋅ Awall + ΔU tb ⋅ Aenvelope Walls and roofs to unheated rooms 0.5
- Floor to ground 0.6
- Walls and floor to unheated crawl
space
H T = ΣU wall ⋅ Awall ⋅ Fx + ΔU tb ⋅ Aenvelope
05.05.2011 SS 10/11 55
56. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
DEGREE-DAYS METHOD
TOTAL HEATING DEMAND
DEGREE-DAYS
z
[Kd/a]
Gt 20 /15 = ∑ (Tin − Tout )
1 [°Cd/a]
• Tout represents mean DAILY values
• Sets up a “heating limit” (15°C), above which no space heating is
required. For this conditions (Tin-Tout)=0
• Below the “heating limit”, (Tin-Tout) is calculated and added up to
give a value of the “degrees-day”
05.05.2011 SS 10/11 56
57. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
DEGREE-DAYS METHOD
TOTAL HEATING DEMAND
[Wh/a] Qlosses = Σ ( H T + H V ) ⋅ Gt Q losses = Σ ( H T + H V ) ⋅ (Tin − Tout ) ⋅ t M
months
days
[Wh/a] QSolar , windows = orientation Awindows ⋅ g i ⋅ FF ⋅ Fs ⋅ Gwindow
Σ
QSolar , windows = Σ Awindows ⋅ g i ⋅ FF ⋅ Fs ⋅ Gwindow
months
[kWh/a] Qint_ gains = 22 ⋅ AN
Qint_ gains = Σ 5 ⋅ AN ⋅ 24 ⋅ tM
months
[Wh/a] Qlosses = Qh − η (Qsolar − Qint ernal ) Qh = Qlosses − η (Qsolar , windows − Qint ernal )
05.05.2011 SS 10/11 57
58. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
DYNAMIC TOOLS
– The equations for steady state conditions are not valid
here!!!-> Energy stored in the building structure plays a
role
– FREEware available (Hourly simulations):DOE2, eQUEST,
ePLUS (http://www.doe2.com/ )
Much more accurate results
× Require the description of the HVAC system as INPUT
× Time demanding to learn how to work with them: weather
data for Stüdl Hütte, etc… may not be in database
05.05.2011 SS 10/11 58
59. INTRODUCTION PHYS. PPLES. ENERGY BALANCES CALC. METHODS
STATIONARY METHODS
• STATIC (simplified) METHODS & SOFTWARE:
– Based on the steady-state simple equation -> quite simple
calculations
Depends only on (rough) CLIMATIC data and the
BUILDING ENVELOPE -> Does not require the description
of the HVAC system as INPUT
× Much more rough results
– Examples: “DEGREE-DAY Method” and Monthly
simplified method in EnEV http://www.uni-
kassel.de/fb6/bpy/de/index.html
05.05.2011 SS 10/11 59
60. THANK YOU FOR YOUR
THANKS FOR YOUR
ATTENTION!!!
ATTENTION!!!!!!
05.05.2011 SS 10/11 60
61. EXAMPLE 3.0m
• AN = 147m2 ; Vbrutto = 580 m3 3.0m
10m
• Awalls = 209.34 m2; Afloor = 88.2 m2; Aroof = 88.2
m2 7.35m
• Awindows: S 15 m2; E/W 10m2; N 5.5 m2
• Uwalls = 0.45 W/m2K (walls); • G19/10 = 2750 °Cd/a (Hamburg)
Ufloor-roof = 0.3 W/m2K (floor and roof);
Orientation
Solar
radiation
Uwindows = 1.4 W/m 2K (windows) [j] [kWh/m²]
Nord 136
• Utb = 0.1 W/m 2K
Süd 349
• n =0.6 h-1 Ost 220
West 220
• Windows: Ff= 0.7; Fs=0.9;g=0.58;
• Heavy building
05.05.2011 SS 10/11 61
T 19°C