| Title | By | Posted On |
| Building Science - Stud Cavity R Value Determination |
MikeDuclos |
3/13/2008 |
Hi,
I use a BCAM-SD, and I'd like to know if it is possible to determine the effective R Value of the wall cavity between two studs. As an example, a house I am working on has a foam which may be old UFFI in the stud cavities. My home energy modeling software uses a stud cavity R Value as an input. Thanks ! |
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| Re:Building Science - Stud Cavity R Value Determination |
IRJay |
3/13/2008 |
| Dr. Bob Madding has built and is currently testing such a calculator. The tests and the tool will be presented at the 2008 Inframation conference in Reno. |
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| Re:Building Science - Stud Cavity R Value Determination |
mlehman |
3/13/2008 |
| Doesnt your camera have an automatic way to shoot the outside and then the inside and it will calculate the R value. |
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| Re:Building Science - Stud Cavity R Value Determination |
cflaws |
4/2/2008 |
IRJay wrote: Madding has built and is currently testing such a calculator. The tests and the tool will be presented at the 2008 Inframation conference in Reno. Interested in what I have read here on determination of actual R-value, for use in assessing build quality within properties we have.
Now proud owner of a new Flir B400, and quickly dragging myself up the learning curve. (Level 1 course in a few weeks time.)
Currently trying to get my head around the science and variables, to come up with some way of estimating U value from field imagery as a building diagnosis tool. Don’t want to re-invent the wheel and any links to similar studies/research would be appreciated.
Main areas of work are commercial/healthcare and educational facilities, with building pathology and energy management being the main influencing areas. Want to get to position to question/verify/dissemble U value of individual components of the building. (photo attached of external facade of a secondary school showing the radiated heat loss)
Unfortunately a trip to Reno from sunny Scotland is out of the question.
Can I therefore ask if anyone knows if the papers presented at the conference will be published to allow Global readership, and if so where?
Any links to similar studies would also be appreciated.
Many thanks in advance.
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| Re:Building Science - Stud Cavity R Value Determination |
Gary Orlove |
4/15/2008 |
Dear CFlaws,
"Can I therefore ask if anyone knows if the papers presented at the conference will be published to allow Global readership, and if so where?"
All papers at the InfraMation conference are available for purchase at this web site. We offer the printed version (in color) or a fully searchable CD version, or both.
See http://www.infraredtraining.com/store/
Gary Orlove
Infrared Training Center |
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| Re:Building Science - Stud Cavity R Value Determination |
cflaws |
6/18/2008 |
Gary Orlove wrote:laws,
"Can I therefore ask if anyone knows if the papers presented at the conference will be published to allow Global readership, and if so where?"
All papers at the InfraMation conference are available for purchase at this web site. We offer the printed version (in color) or a fully searchable CD version, or both.
See http://www.infraredtraining.com/store/
Gary Orlove
Infrared Training Center Gary,
Many thanks.
Colin |
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| Re:Building Science - Stud Cavity R Value Determination |
glassman |
7/1/2008 |
cflaws wrote: Interested in what I have read here on determination of actual R-value, for use in assessing build quality within properties we have.
Now proud owner of a new Flir B400, and quickly dragging myself up the learning curve. (Level 1 course in a few weeks time.)
Currently trying to get my head around the science and variables, to come up with some way of estimating U value from field imagery as a building diagnosis tool. Don’t want to re-invent the wheel and any links to similar studies/research would be appreciated.
Main areas of work are commercial/healthcare and educational facilities, with building pathology and energy management being the main influencing areas. Want to get to position to question/verify/dissemble U value of individual components of the building. (photo attached of external facade of a secondary school showing the radiated heat loss)
Unfortunately a trip to Reno from sunny Scotland is out of the question.
Can I therefore ask if anyone knows if the papers presented at the conference will be published to allow Global readership, and if so where?
Any links to similar studies would also be appreciated.
Many thanks in advance.
Well arnt you the lucky one with the new Flir B400.
you ask the question on 'R' value, there are calculations out there and they are usualy embraced within the SAP calcs as they take in all the variables of each building. This needs to be very precise on identification as differing materials perform differently and it is not a given that if you place two like rated materials together you get twice the value. If only life was that simple. To calc the 'U' value requires the whole structure to be listed with the given 'U' value of each component added together you then basicaly rob peter to pay paul if say the roof is poor and the glass is excellent. The short answer is add all together then devide by the number of components. Not realy that simple but gives you a broad idea of how it is done. Now can this be done with a camera the answer is yes provinance of products can be ratified but an overall that would be a long job and may not be very accurate. But then we have some very clever folks in the UK that are working on all sorts so do not be surprised if something does not pop out of the woodwork. Stay well
The Verifier |
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| Re:Building Science - Stud Cavity R Value Determination |
IRT Surveys |
8/8/2008 |
glassman wrote: Well arnt you the lucky one with the new Flir B400.
you ask the question on 'R' value, there are calculations out there and they are usualy embraced within the SAP calcs as they take in all the variables of each building. This needs to be very precise on identification as differing materials perform differently and it is not a given that if you place two like rated materials together you get twice the value. If only life was that simple. To calc the 'U' value requires the whole structure to be listed with the given 'U' value of each component added together you then basicaly rob peter to pay paul if say the roof is poor and the glass is excellent. The short answer is add all together then devide by the number of components. Not realy that simple but gives you a broad idea of how it is done. Now can this be done with a camera the answer is yes provinance of products can be ratified but an overall that would be a long job and may not be very accurate. But then we have some very clever folks in the UK that are working on all sorts so do not be surprised if something does not pop out of the woodwork. Stay well
The Verifier You are welcome to visit our office in Dundee. We do exactly what you want to do. Visit the website at www.irtsurveys.co.uk
If you want to come in you get call me directly on 07986 045 964. we have written unique software that quantifies energy loss from thermal images. You can upload your images to us and would be delighted to turn them into quantified reports for you. Stewart. |
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| Re:Building Science - Stud Cavity R Value Determination |
Prunty |
1/15/2009 |
glassman wrote: Well arnt you the lucky one with the new Flir B400.
you ask the question on 'R' value, there are calculations out there and they are usualy embraced within the SAP calcs as they take in all the variables of each building. This needs to be very precise on identification as differing materials perform differently and it is not a given that if you place two like rated materials together you get twice the value. If only life was that simple. To calc the 'U' value requires the whole structure to be listed with the given 'U' value of each component added together you then basicaly rob peter to pay paul if say the roof is poor and the glass is excellent. The short answer is add all together then devide by the number of components. Not realy that simple but gives you a broad idea of how it is done. Now can this be done with a camera the answer is yes provinance of products can be ratified but an overall that would be a long job and may not be very accurate. But then we have some very clever folks in the UK that are working on all sorts so do not be surprised if something does not pop out of the woodwork. Stay well
The Verifier R Value is the inverse of U value. There is currently nothing to verify R Values in the field.
To get the R value of a wall requires Seperating the different components ie. percentage glazing, wood etc. and adding these together(remember R Values are additive, U values are not). You end up with a whole wall R value. This does not take into account the installation quality. However if you are doing Energy Star rating for new homes the software gives a value depending on installation quality. |
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| Re:Building Science - Stud Cavity R Value Determination |
karoluxas |
1/7/2010 |
Can anybody provide a function how to calculate R value, when outside T, inside T and surface average T are known.
Thanks
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| Re:Building Science - Stud Cavity R Value Determination |
StecGuy |
1/14/2010 |
karoluxas wrote: body provide a function how to calculate R value, when outside T, inside T and surface average T are known.
Thanks
It is not quite as simple as those three known factors. You have to take into consideration the changes in temperature affected by the mechanical heating cooling system, and the amount of air they are moving to keep the artificial temps what they are on the inside.
The answer above stating averaging the individual r-value of each component is the more common way. |
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| Re:Building Science - Stud Cavity R Value Determination |
BJenkins |
1/29/2010 |
Prunty wrote: R Value is the inverse of U value. There is currently nothing to verify R Values in the field.
To get the R value of a wall requires Seperating the different components ie. percentage glazing, wood etc. and adding these together(remember R Values are additive, U values are not). You end up with a whole wall R value. This does not take into account the installation quality. However if you are doing Energy Star rating for new homes the software gives a value depending on installation quality. Although this will not break down the wall for you, we use our FLIR camera and a Testo 435 http://www.aikencolon.com/Testo-435-HVAC-Test-Kits_c_1158.html to calculate R Value and U Value. It uses three sensors on the wall (structure) then uses a wireless probe on the opposite side of the wall for RH and temperature measurements. It then calculates the R/U value. I know of no other device that can do it.
We back up our findings with the 435 like you would with any other meter (moisture, nuclear, thermocoupler, etc)
Brian
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