This document discusses how the thermal conductivity and R-value of insulation materials are dependent on temperature and climate conditions, and can impact building durability. It notes that standardized testing may not accurately capture real-world performance, and that accounting for temperature-dependent properties is important for predicting condensation and durability. The document advocates for manufacturers providing tested data under various conditions, and considering insulation performance relative to specific project locations and environments.
PRACTICAL ISSUES ASSOICATED WITH THE USE OF INFRARED THERMOGRAPHY FOR DETECTI...John Kingsley
PRACTICAL ISSUES ASSOICATED WITH THE USE OF INFRARED
THERMOGRAPHY FOR DETECTION OF HEAT, AIR AND
MOISTURE DEFICIENCIES IN BUILDING ENVELOPES
DETECTING THERMAL ANOMALIES RELATED TO CONDUCTIVE HEAT TRANSFER
In this project, experimentation is done on Vapour Compression Refrigeration System
[VCRS] as the COP is high for this system and it is the present trend of the HVAC in the
domestic industry. This study presents investigation of best suited refrigerant and
insulation combination for gas pipeline and liquid pipeline of a split air conditioning
system. Analysis are performed for R22-Chlorodiflouromethane, a HydroChloroFlouro
Carbon refrigerant, which has been using in the present world that cause both global
warming and ozone layer depletion and R410a, mixture of di-flouromethane and
pentaflouroethane, a Hydroflouro carbon refrigerant, which is future of HVAC which
reduces the effect of ozone layer depletion [ODP] and Global Warming Potential
[GWP].For these two refrigerants, we had found out the best insulation suitable as
insulation also affects the COP of air conditioner, which has been observed from the
literature. Minimizing the temperature of refrigerant in suction line helps condensing unit
work more effectively intern the system performance increases. This reduces the overall
power required for working of air conditioner, thereby reducing the maintenance cost of
system. Also, it helps the manufacturer to provide best type of insulation for the system at
reduced cost thereby reducing overall cost of VCRS.To perform the experimental
comparison, 16 tests were carried out for 5 times with each refrigerant Insulation
combination. From analysis it is observed that, COPA for NRF+AF gives highest value
for R22 and R410awhen compared to various insulation materials. Power required for
VCRS is greater while using R410a than R22. So In this work the main energy parameters
such as COP and work required for compressor are analysed and discussed.
International Journal of Engineering Research and Development (IJERD)IJERD Editor
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals,
yahoo journals, bing journals, International Journal of Engineering Research and Development, google journals, hard copy of journal
Investigation of Different Types of Cement Material on Thermal Properties of ...IJERA Editor
One of the challenges in sustainable development is to optimize the energy efficiency of buildings during their
lifespan. Nowadays the applying of different types of cements in modern concretes provide low embodied CO2
with the intrinsic property called “thermal mass” that reduces the risk of overheating in the summer and
provides passive heating in the winter. Thermal mass is affected by thermal properties of concrete which it is the
ability of the element to exchange heat with the environment and is based on thermal capacity, conductivity, and
density. Laboratory experiments measured density, specific capacity and thermal conductivity of sustainable
concrete mixes with various percentages of GGBS, PFA, SF. The results contribute to the investigation of the
performance of thermal properties performance in sustainable concrete.
PRACTICAL ISSUES ASSOICATED WITH THE USE OF INFRARED THERMOGRAPHY FOR DETECTI...John Kingsley
PRACTICAL ISSUES ASSOICATED WITH THE USE OF INFRARED
THERMOGRAPHY FOR DETECTION OF HEAT, AIR AND
MOISTURE DEFICIENCIES IN BUILDING ENVELOPES
DETECTING THERMAL ANOMALIES RELATED TO CONDUCTIVE HEAT TRANSFER
In this project, experimentation is done on Vapour Compression Refrigeration System
[VCRS] as the COP is high for this system and it is the present trend of the HVAC in the
domestic industry. This study presents investigation of best suited refrigerant and
insulation combination for gas pipeline and liquid pipeline of a split air conditioning
system. Analysis are performed for R22-Chlorodiflouromethane, a HydroChloroFlouro
Carbon refrigerant, which has been using in the present world that cause both global
warming and ozone layer depletion and R410a, mixture of di-flouromethane and
pentaflouroethane, a Hydroflouro carbon refrigerant, which is future of HVAC which
reduces the effect of ozone layer depletion [ODP] and Global Warming Potential
[GWP].For these two refrigerants, we had found out the best insulation suitable as
insulation also affects the COP of air conditioner, which has been observed from the
literature. Minimizing the temperature of refrigerant in suction line helps condensing unit
work more effectively intern the system performance increases. This reduces the overall
power required for working of air conditioner, thereby reducing the maintenance cost of
system. Also, it helps the manufacturer to provide best type of insulation for the system at
reduced cost thereby reducing overall cost of VCRS.To perform the experimental
comparison, 16 tests were carried out for 5 times with each refrigerant Insulation
combination. From analysis it is observed that, COPA for NRF+AF gives highest value
for R22 and R410awhen compared to various insulation materials. Power required for
VCRS is greater while using R410a than R22. So In this work the main energy parameters
such as COP and work required for compressor are analysed and discussed.
International Journal of Engineering Research and Development (IJERD)IJERD Editor
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals,
yahoo journals, bing journals, International Journal of Engineering Research and Development, google journals, hard copy of journal
Investigation of Different Types of Cement Material on Thermal Properties of ...IJERA Editor
One of the challenges in sustainable development is to optimize the energy efficiency of buildings during their
lifespan. Nowadays the applying of different types of cements in modern concretes provide low embodied CO2
with the intrinsic property called “thermal mass” that reduces the risk of overheating in the summer and
provides passive heating in the winter. Thermal mass is affected by thermal properties of concrete which it is the
ability of the element to exchange heat with the environment and is based on thermal capacity, conductivity, and
density. Laboratory experiments measured density, specific capacity and thermal conductivity of sustainable
concrete mixes with various percentages of GGBS, PFA, SF. The results contribute to the investigation of the
performance of thermal properties performance in sustainable concrete.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Effect of controlling parameters on heat transfer during spray impingement co...BIBHUTI BHUSAN SAMANTARAY
The heat transfer characteristics of air-water spray impingement cooling of stationary steel plate was experimentally investigated. Experiments were conducted on an electrically heated flat stationary steel plate of dimension 120 mm x 120 mm x 4 mm. The controlling parameters taken during the experiments were air-water pressures, water flow rate, nozzle tip to target distance and mass impingement density. The effects of the controlling parameters on the cooling rates were critically examined during spray impingement cooling. Air assisted DM water was used as the quenchant media in the work. The cooling rates were calculated from the time dependent temperature profiles were recorded by NI-cRIO DAS at the desired locations of the bottom surface of the plate embedded with K-type thermocouples. By using MS-EXCEL the effects of these cooling rate parameters were analysed The results obtained in the study confirmed the higher efficiency of the spray cooling system and the cooling strategy was found advantageous over the conventional cooling methods in the present steel industries.
THE INFLUENCE OF SHAPE AND SPATIAL DISTRIBUTION OF METAL PARTICLES ON THE THE...IAEME Publication
In this paper, the effect of shape and spatial distribution of metal particles on the thermal conductivity of nickel-silicone composites is investigated to find out the optimum shape and spatial distribution of metal particles in polymer composites. Various finite element models with different particles shapes and arrangements are constructed to predict composite thermal conductivity.
Experimental study of heat transfer parameters of serrated plate fin heat exc...ijiert bestjournal
The heat transfer and flow friction Characteristics of plate f in surfaces are presented in terms of the Colburn factor j and the Fanning friction factor f verses Reynolds number Re,the relationships being different for different surfaces. The laminar flow model predicts j and f values at low Reynolds number;the data is throughout the range of interest. Velocity and temperature fields have been Computed and j and f factors determined over appropriate range of Reynolds number and geometric dim ensions. For this work I have designed heat exchanger according to procedure of design of serrated pl ate fin heat exchanger [12],Correlation used for finding various heat transfer parameters having Reynolds number l ess than 200 [6]. Experimental setup was manufactured using calculated parameters of design. The eff ects of the materials Brass and Copper SPFHE on the heat transfer enhancement and friction factor behaviors in lam inar flow regimes (Re < 200) are described. The fin dimension of serrated type plate fin heat exchanger SPFHE (H=3mm,t=0.2mm,s=2.5,lf=5mm for hot fluid and H=9.5mm,t=0.2mm,s=,lf=5mm for Cold fluid) same for both mat erials. On this setup readings were taken by varying flow rate of hot oil,at Constant air for differe nt temperatures of selected materials. After getting readings Calculations were done for heat transfer para meters like Reynolds number,Colburn factor and Fanning friction factor.
Coefficient of Performance Enhancement of Refrigeration CyclesIJERA Editor
Refrigerator is one of the home appliance utilizing mechanical vapor compression cycle in its process. Performance of the systems become the main issue and many researches are still ongoing to evaluate and improve the efficiency of any used system. Therefore, this paper presents an experimental investigation of the performance of the refrigeration cycles. A small rrefrigerator is used as the test rig. The Coefficient of Performance (COP) is studied by using different condenser designs and under varying evaporator loads. Three condenser designs are used in present work. These condensers are regular condenser of domestic refrigerator, condenser with copper plain tubes (Cond.1) and condenser with copper tubes welded with stainless steel flat plate (Cond.2). pressures and temperatures measurements of each point in the refrigeration cycle are collected in order to evaluate the refrigerator performance. The results showed that the average COP of Cond.1 and Cond.2 are increased up to 20 % and 14% respectively more than regular condenser design under no load. The evaporator load effects on the machine performance, where the COP of the machine increases with the increase of the evaporator load.
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology
An Experimental Investigations of Nusselt Number for Low Reynolds Number in a...IJMER
: In this paper, we present results of measured heat transfer coefficients for each sodium
carboxymethyl cellulose concentration at two different lengths of coil L=2.82m, L=2.362m and with
two different heat inputs 1.0kW and 1.5kW . Test solutions of sodium carboxymethyl cellulose
concentrations of 0.05%, 0.1%, 0.15% and 0.2% were used in our experimental runs. A four flat blade
paddle impeller was used to verify the mixed fluid, under steady heating of Newtonian and nonNewtonian
fluids in an flat bottom agitated vessel. A Kanthal Heating Element Equipment have been
design and fabricated to optimize the heating of the fluids in an agitated vessel. The rehogical properties
like flow behavior index, consistency index and viscosity data were carried experimentally using Rotating
Cylinder Method for all the test solutions. A correlations have been presented for Newtonian and non
Newtonian fluids in laminar flow conditions
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Effect of controlling parameters on heat transfer during spray impingement co...BIBHUTI BHUSAN SAMANTARAY
The heat transfer characteristics of air-water spray impingement cooling of stationary steel plate was experimentally investigated. Experiments were conducted on an electrically heated flat stationary steel plate of dimension 120 mm x 120 mm x 4 mm. The controlling parameters taken during the experiments were air-water pressures, water flow rate, nozzle tip to target distance and mass impingement density. The effects of the controlling parameters on the cooling rates were critically examined during spray impingement cooling. Air assisted DM water was used as the quenchant media in the work. The cooling rates were calculated from the time dependent temperature profiles were recorded by NI-cRIO DAS at the desired locations of the bottom surface of the plate embedded with K-type thermocouples. By using MS-EXCEL the effects of these cooling rate parameters were analysed The results obtained in the study confirmed the higher efficiency of the spray cooling system and the cooling strategy was found advantageous over the conventional cooling methods in the present steel industries.
THE INFLUENCE OF SHAPE AND SPATIAL DISTRIBUTION OF METAL PARTICLES ON THE THE...IAEME Publication
In this paper, the effect of shape and spatial distribution of metal particles on the thermal conductivity of nickel-silicone composites is investigated to find out the optimum shape and spatial distribution of metal particles in polymer composites. Various finite element models with different particles shapes and arrangements are constructed to predict composite thermal conductivity.
Experimental study of heat transfer parameters of serrated plate fin heat exc...ijiert bestjournal
The heat transfer and flow friction Characteristics of plate f in surfaces are presented in terms of the Colburn factor j and the Fanning friction factor f verses Reynolds number Re,the relationships being different for different surfaces. The laminar flow model predicts j and f values at low Reynolds number;the data is throughout the range of interest. Velocity and temperature fields have been Computed and j and f factors determined over appropriate range of Reynolds number and geometric dim ensions. For this work I have designed heat exchanger according to procedure of design of serrated pl ate fin heat exchanger [12],Correlation used for finding various heat transfer parameters having Reynolds number l ess than 200 [6]. Experimental setup was manufactured using calculated parameters of design. The eff ects of the materials Brass and Copper SPFHE on the heat transfer enhancement and friction factor behaviors in lam inar flow regimes (Re < 200) are described. The fin dimension of serrated type plate fin heat exchanger SPFHE (H=3mm,t=0.2mm,s=2.5,lf=5mm for hot fluid and H=9.5mm,t=0.2mm,s=,lf=5mm for Cold fluid) same for both mat erials. On this setup readings were taken by varying flow rate of hot oil,at Constant air for differe nt temperatures of selected materials. After getting readings Calculations were done for heat transfer para meters like Reynolds number,Colburn factor and Fanning friction factor.
Coefficient of Performance Enhancement of Refrigeration CyclesIJERA Editor
Refrigerator is one of the home appliance utilizing mechanical vapor compression cycle in its process. Performance of the systems become the main issue and many researches are still ongoing to evaluate and improve the efficiency of any used system. Therefore, this paper presents an experimental investigation of the performance of the refrigeration cycles. A small rrefrigerator is used as the test rig. The Coefficient of Performance (COP) is studied by using different condenser designs and under varying evaporator loads. Three condenser designs are used in present work. These condensers are regular condenser of domestic refrigerator, condenser with copper plain tubes (Cond.1) and condenser with copper tubes welded with stainless steel flat plate (Cond.2). pressures and temperatures measurements of each point in the refrigeration cycle are collected in order to evaluate the refrigerator performance. The results showed that the average COP of Cond.1 and Cond.2 are increased up to 20 % and 14% respectively more than regular condenser design under no load. The evaporator load effects on the machine performance, where the COP of the machine increases with the increase of the evaporator load.
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology
An Experimental Investigations of Nusselt Number for Low Reynolds Number in a...IJMER
: In this paper, we present results of measured heat transfer coefficients for each sodium
carboxymethyl cellulose concentration at two different lengths of coil L=2.82m, L=2.362m and with
two different heat inputs 1.0kW and 1.5kW . Test solutions of sodium carboxymethyl cellulose
concentrations of 0.05%, 0.1%, 0.15% and 0.2% were used in our experimental runs. A four flat blade
paddle impeller was used to verify the mixed fluid, under steady heating of Newtonian and nonNewtonian
fluids in an flat bottom agitated vessel. A Kanthal Heating Element Equipment have been
design and fabricated to optimize the heating of the fluids in an agitated vessel. The rehogical properties
like flow behavior index, consistency index and viscosity data were carried experimentally using Rotating
Cylinder Method for all the test solutions. A correlations have been presented for Newtonian and non
Newtonian fluids in laminar flow conditions
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Amazon Web Services Online Training is Offering at Glory IT Technologies. Amazon Web Services (AWS) is a leading cloud-based services platform, and developers who want to keep current need to know what benefits AWS has to offer. This course provides you with a solid conceptual foundation on which to architect your next cloud-based application
DevOps Online Training is Offering at Glory IT Technologies. In this course, we look at the necessity of Devops and how a DevOps transformation can help focus on value and streamlined delivery. We will also cover concepts like Automation and technology which play huge roles in DevOps success; in this course we'll analyze the major capability areas and which technologies can get your team on its way
Improving envelope thermal insulation in construction projects using nanotech...eSAT Journals
Abstract
Conservation of energy consumption in the construction industry is becoming more important than ever due to global issues
related to the increased energy demand. Energy consumption in heating and cooling systemsfor commercial and residential
buildings is a major portion of the overall energy consumption. One important approach to respond to this type of consumption is
to enhance the thermal resistance (R value) of building envelopes with a special focus on the insulation materials.
Nanotechnology as an emergent science and engineering field is developing solutions to enhance the resistance value of different
building products withinnovative methodsincluding, reducing the pore size of insulation materials. This paper presents a review of
utilization of nano-enabled products to improve insulation materials. The research involves exploring the literatures that cover
area of technology application in addition to the commercial products currently being offered in the construction market.
Findings indicate that the relatively high cost of the nano-products is due to lack of both mass production and familiarity of public
to these products.
Key Words: Thermal Insulation, Nano Insulation, Envelope, Heat Resistance, Construction Projects.
LNG Industry Magazine (Logical Thinking) Feb 2016Joe Hughes
Dyplast Products’ new article in LNG Industry Magazine titled "Logical Thinking" is an examination of the complexities surrounding insulant performance at cryogenic temperatures.
Physical properties of a particular insulant are often measured only at ambient temperatures. This article aims to use logical thinking to examine the performance of insulants at LNG (cryogenic) temperatures.
Fortunately, standards such as ASTM and CINI increasingly require physical properties to be measured at cryogenic temperatures, so that in the future such logical extrapolations may be less necessary.
LNG Industry Magazine (Logical Thinking) Feb 2016Dyplast Products
Dyplast Products’ new article in LNG Industry Magazine titled "Logical Thinking" is an examination of the complexities surrounding insulant performance at cryogenic temperatures.
Physical properties of a particular insulant are often measured only at ambient temperatures. This article aims to use logical thinking to examine the performance of insulants at LNG (cryogenic) temperatures.
Fortunately, standards such as ASTM and CINI increasingly require physical properties to be measured at cryogenic temperatures, so that in the future such logical extrapolations may be less necessary.
Engineering Research Publication
Best International Journals, High Impact Journals,
International Journal of Engineering & Technical Research
ISSN : 2321-0869 (O) 2454-4698 (P)
www.erpublication.org
Experimental analysis of partial and fully charged thermal stratified hot wat...IAEME Publication
Developing competent and economical energy storage devices such as thermal energy storage have great importance as it reduces the gap between demand and supply of energy Presently, the
most common storage devices utilize phase change materials (commonly known as eutectic salts),
rock beds and hot water storage. In most cases stratified storage tanks with various capacities are employed for storing energy which was most economical.
PASSIVE THERMAL CONTROL FOR BUILDINGS IN TEMPERATE REGIONS-COMPARISON OF CAVI...paperpublications3
Abstract: Providing thermal comfort without excess space and conditioning costs is one of the primary requirements of buildings. Therefore, thermal control is an important aspect in almost all buildings. Understanding heat transfer and the temperature distribution through building materials and assemblies is also important for assessing energy use. Thermal comfort, thermal movements, durability, and the potential for moisture problems. The control of heat flow in buildings requires insulation layers compromised with few thermal bridges, an effective air barrier system, good control of solar radiation, and management of interior heat generation. Walls play a huge role in the heat gain and loss in buildings, thus, making wall an important subject in passive thermal control in buildings. This article is aimed at analyzing cavity walls and solid brick walls and comparing them for home construction in temperate regions. Temperate regions need good insulating walls, thus reducing heat loss via walls to its minimal, which in turn reduces the cost of active heating measures in buildings.
Proper ventilation in one of the primary requirements of any domestic or commercial buildings. The conventional method employs usage of air conditioning or air cooling systems which requires high power consumption. The solar driven ventilation systems can be used in buildings which doesn’t require any external power. The current research reviews various researches conducted in improving system of passive ventilation along use of phase change material as energy storage system. Passive design of buildings does not use the electrical and mechanical systems in providing comfortable indoor environment. Prem Shankar Sahu | Praveen Kumar | Ajay Singh Paikra "Review on Solar Chimney Ventilation" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-4 , June 2021, URL: https://www.ijtsrd.compapers/ijtsrd42427.pdf Paper URL: https://www.ijtsrd.comengineering/mechanical-engineering/42427/review-on-solar-chimney-ventilation/prem-shankar-sahu
Theoretical Model Computations for Different Components of a Hot Box Type Sol...IJCMESJOURNAL
Many countries having tremendous solar potentials are also the victim of the power crises since the available solar energy is not utilized efficiently. It has been recognized that the widespread use of solar thermal appliances (STA) for domestic work is being held back by excessive cost, low efficiency, high weight, and inconvenience of user and by lack of confidence in the long term durability of the material. In the present work, the limitations of materials used in various components of commercial available STA have been underlined and it has been shown that use of polymeric materials as specific component in solar thermal appliances can solve most of the existing limitations and may improve the efficiency of the existing appliances. In this paper theoretical model computations have been done for different components of a hot-box type solar cooker viz., glaze, insulation and casing material for the spectral transmittance, the solar flux absorbed and the optical efficiency, thermal efficiency, heat loses, weight, thermal profile and adjusted cooking power for several suitable materials, both conventional as well as new polymeric materials. Significant improvement in all the mentioned characteristic properties /figures of merit of the solar cooker can be achieved if right combination of polymeric materials is used in making glaze, insulation and casing. The present study offers that component improvements of a system results into cost reduction, extended lifetime and makes system easy to handle. This shall surely help in popularization of the solar appliances and enhancement of eco-friendly environment.
A Comparison and Sustainability Analysis of Solar Thermal ReceiversPratish Rawat
Solar Thermal receivers are major component in applications, such as solar water heater for generating hot water for commercial and domestic purpose, solar space heating, concentrating solar power, or solar assist heating, ventilation and air conditioning. There are evacuated tubes and aerogel based solar receivers. A receiver should ideally absorb and convert incident sunlight into heat. For high efficiency receiver should not loss much heat out of its boundary. However, some radiation and convection heat loss occur in every receiver. In this paper comparative analysis of two type high efficiency receiver, evacuated tube and aerogel receivers has been done based on the parameters like sustainability, effectiveness, efficiency, and life cycle. A mathematical model of each receiver has been developed with other comparison parameter. Upon analysis it could be predict that aerogel receiver more sustainable and overall impact than vacuum or evacuated type receiver. Aerogel receiver also gives flexibility of design, geometry and temperature.
LNG Industry Magazine (Risk Mitigation Standards) July 2016Joe Hughes
Experience has demonstrated that insulation systems within LNG facilities are often ‘under-designed’ when compared to other mechanical systems. Decades of lessons learned from
under-designing other mechanical systems, such as piping materials, welding, compressors, relief valves, etc., have led to a keen awareness among LNG engineers regarding impacts on safety, plant reliability, process efficiency, energy loss, and
environmental compliance.
The purpose of this article is to offer a macro-level discussion
of the following:The role of standards in mitigating insulation risks. Which standards are becoming dominant for LNG insulation. Where standards must be supplemented with broader risk mitigation.
LNG Industry Magazine (Risk Mitigation Standards) July 2016Dyplast Products
Experience has demonstrated that insulation systems within LNG facilities are often ‘under-designed’ when compared to other mechanical systems. Decades of lessons learned from
under-designing other mechanical systems, such as piping materials, welding, compressors, relief valves, etc., have led to a keen awareness among LNG engineers regarding impacts on safety, plant reliability, process efficiency, energy loss, and
environmental compliance.
The purpose of this article is to offer a macro-level discussion
of the following:The role of standards in mitigating insulation risks. Which standards are becoming dominant for LNG insulation. Where standards must be supplemented with broader risk mitigation.
1. The Impact of Thermal Conductivity on
Building Enclosure Durability
W
hen designers are deciding which insulation
products to specify for a given project, two common
questions come to mind: “What is the R-value?”
and “What is the permeance?” It would be unfair to take credit
for the discovery of Relativity; however, the answer to these two
questions is, “It’s all relative.” If Einstein hadn’t been so focused
on the speed of light, he would have had the time to establish
the third theory of relativity: R-value relativity. Thermal
insulation’s effective performance and permeance properties
are relative and dependent upon project location (specifically,
temperature and climate). In other words, a building assembly
will perform differently in Miami, Florida, than it would in
Anchorage, Alaska. Therefore, it is essential to understand
the dynamics of building products under regional climatic
conditions in order to increase overall building durability.
Generalizations Are Not Effective
Insulation types should not be treated equally, as there is a
wide range of varying performance characteristics. However,
some codes and standards organizations are pushing for
equal testing on these types of products. Buildings aren’t
constructed in laboratories, so why do semi-irrelevant tests,
which have no bearing on real life in-situ scenarios, persist? If
buildings were built with the quality and precision (including
white gloves and lab coats) accomplished in the laboratory,
building failures wouldn’t exist. Obviously, building failures
do exist, and the industry spends millions upon millions of
dollars annually on building repairs. A better mechanism for
relevant building components and assemblies testing needs to
be in place. Designers should ask manufacturers and product
suppliers for tested data that is relevant for their applications
and locations. It’s understandable that codes and standards are
necessary for marketing value. However, project teams should
consider additional questions and analysis outside the realm of
standardized testing.
In layman’s terms, R-value is defined as a material’s
resistance to heat transfer. One might assume that the
higher the R-value, the lower the thermal conductivity
(k-value)—resulting in higher performance. However, the
answer (again) is that it is relative. Three mechanisms of heat
transfer cumulatively determine the relativity of performance:
conduction, convection and radiation. In general, residential
and commercial insulations use an ASTM Standard test
method to measure heat flow through a given medium. In the
case of insulation, the standardized test to determine heat flow
is ASTM C518, Standard Test Method for Steady-State Thermal
Transmission Properties by Means of the Heat Flow Meter
Apparatus. This standardized approach is an accurate way to
measure and determine the R-value of a product. However,
the mean temperature to report R-value is stated at 75o
F
(24o
C). It doesn’t make sense to insulate buildings from room
temperature, but using this mean temperature of 75o
F (24o
C)
results in higher repeatable accuracy. So, is it the intention
of this test procedure to produce a more accurate result to
the nearest third decimal place or actually provide valuable
and applicable information for designers to increase energy
efficiency and envelope durability? As an industry, a great deal
of knowledge and awareness are required to fully understand
how temperature-dependent thermal conductivity (TDTC)
impacts building and component durability. Hopefully,
information provided in this article will resonate with
designers and direct them to ask the right questions, including
“What is the R-value of a product for my climate zone?”
Researchers, organizations and educational institutions
conduct research to understand how temperature affects
insulation materials’ thermal conductivity. Organizations,
such as the National Roofing Contractors Association
(NRCA), Building Science Consulting Inc. (BSCI), RDH
and the University of Waterloo in Ontario, Canada, all
invest time, money and resources to promote the in-situ
22 JOURNAL OF THE NATIONAL INSTITUTE OF BUILDING SCIENCES – AUGUST 2015
By Rockford Boyer, B. Arch. Sc., BSSO
Special, General
and R-Value Relativity
Building Enclosure Design
2. performance of insulation under realistic
conditions. Research conducted by these
organizations determined that R-values
are, in fact, dynamic, based on the
temperatures with which they interact.
Depending on the insulation type
(whether mineral fiber or foam plastic),
three or four major variables can
affect the R-value performance of the
insulation. Conduction and convection
exhibit a linear relationship between
temperature and R-value, whereas
radiation impacts R-value to the fourth
power. Additionally, blowing agents
used in certain foam plastic insulations
typically are unaccounted for, but can
have an adverse effect on R-value. These
blowing agents have both a condensation
point and a boiling point, meaning they
have the potential to change from one
phase to another phase based on ambient
temperatures. If the temperature is low
enough, condensation occurs in the
blowing agent, and the increased thermal
conductivity of the liquid in the cell
significantly reduces the R-value. “Figures
1, 2 and 3” (see this page, right and below)
illustrate heat transfer mechanisms,
as well as the effects of condensation
in the cells. Moisture present within
insulation also can drastically reduce that
insulation’s efficiency.
Theory Versus Real World
Although lab tests can help determine
the individual characteristics of a
product, these characteristics can change
drastically when installed or tested as
JOURNAL OF THE NATIONAL INSTITUTE OF BUILDING SCIENCES – AUGUST 2015 23
Figure 1: BSCI tested the apparent R-value on four polyisocyanurate manufacturers’ samples,
including a sample of high-density mineral wool roofing material. LTTR stands for long-term
thermal resistance; NRCA represents that organization’s testing results.
Figure 2: NRCA examined R-value minimum and maximum ranges for polyisocyanurate
samples.
Figure 3: The University of Waterloo tests illustrate the R-value of four common insulation materials at varying temperatures and relative humidities.
Continued on page 24
R-Value vs. Temperature & Humidity
3. 24 JOURNAL OF THE NATIONAL INSTITUTE OF BUILDING SCIENCES – AUGUST 2015
a system. In turning lab test theories
into understandable or real project
situations, a well-known hygrothermal
modeling software program, called
WUFI®
-ORNL/IBP,[1]
now can assess the
combined heat and moisture transfer
in building components based on
building type and local interior and
exterior environments. In WUFI-ORNL/
IBP, a user generates personalized
assembly constructions from a wide
range of default materials, climates
and conditions to predict their in-situ
performance.
Sometimes, though, data associated
with generic or default materials can
be inaccurate, assumed, estimated
or missing completely. This is
the case with one of the generic
polyisocyanurate materials located
in the WUFI-ORNL/IBP database for
North America (see “Figures 4 and
5,” above). “Figure 4” references the
generic default material located in the
North American database, whereas
“Figure 5” is derived from out-of-scope
testing and resembles actual in-situ
temperatures. The two graphs show a
discrepancy between the temperature
versus R-value for the default value,
as well as the actual tested value for
a similar insulation material type.
The objective of this comparison is
not to discredit the software program,
but to educate users on encouraging
manufacturers to input actual test data
into the software database. Product
manufacturers must take responsibility
in providing accurate hygrothermal
data to building professionals to ensure
designs are as realistic as possible.
Refer to “Figure 6” (see below) for
a realistic thermal prediction of an
ASHRAE-compliant wall with the use of
three common continuous insulation
materials.
Thermal Conductivity and
Building Durability
How can R-value affect the durability of
a building assembly? Primarily, it does
so based on the condensation potential
of the condensing plane (e.g., in the
case of “Figure 6,” the sheathing board).
A higher potential for condensation
can occur when low temperatures, high
humidity and low-permeable materials
are present within a building assembly.
Air leakage, which ex-filtrates
from the interior to exterior, also
has a negative impact on interstitial
condensation. This is especially true
if non-permeable components are
used. Predicted maximum temperature
swings for extruded polystyrene
and mineral wool insulation types
are 7o
F (46o
F and 39o
F), whereas
polyisocyanurate insulation has a
maximum fluctuation of 11o
F (43o
F
and 32o
F).
When calculating the potential
condensation hours for a given
time period, utilize temperature-
Figure 4: The WUFI-ORNL/IBP 5.3 database predicted the R-value of polyisocyanurate.
Generic Polyiso R-Value at Range of Exterior Temperatures
Generic Polyiso R-Value at Range of Exterior Temperatures
Exterior Temperature °F
R-ValueperInch
Exterior Temperature °F
R-ValueperInch
Figure 5: BSCI tested and imported polyisocyanurate roof material into WUFI-ORN/IBP to
predict annual energy heat loss. Note the contradicting information from WUFI versus third-party
tested data. Underestimation of the heat loss and condensation hours can be detrimental to
building assemblies.
Figure 6: This code-compliant wall is modeled for the Chicago climate. Note: Insulation depicted
is comprised of mineral wool R7.5 continuous sheathing board and R14 batt.
WUFI Predicted R-Value
3rd-Party Tested R-Value
1” Air Cavity R7.5 Comfortboard IS Moisture Control Layer
Interior Gypsum Board
3/4” Sheathing Board
R14 Comfortbatt
Vapor Control Layer
Brick