Form (hardly) ever follows function : integrating thermal mass.
The words of the late American architect Louis Henry Sullivan point to the heart of green and sustainable design:
"It is the pervading law of all things organic, and inorganic,
of all things physical and metaphysical,
of all things human and all things super-human,
of all true manifestations of the head, of the heart, of the soul, that the life is recognizable in its expression, that form ever follows function. This is the law.”
Also,
“All practical demands of utility should be paramount as basis of planning and design; ...no architectural dictum, or tradition, or superstition, or habit should stand in the way."
The first quote states that things take a certain shape because they perform a certain function. The second reminds architects and engineers to base design on function. Tradition and habits that impede utility should be excised.
These concepts offer a strong foundation for the green building and sustainable design movement. The words “green” and “sustainable” refer to energy efficient and environmentally responsible materials and methods that can be employed without harming future generations.
Accordingly, buildings should take the form of structures that maximize energy efficiency, exhibit green and sustainable design elements, and facilitate the activities specific to the space.
Maximizing Energy Efficiency
Architects and engineers have an opportunity to establish new habits and traditions which transform design features into maximum energy efficiency.
Consider the building envelope, which can represent the largest area of energy consumption or conservation. If maximum energy efficiency is a priority function of a new building, then it is accurate to state that, currently, form (hardly) ever follows function.
Why? Because most buildings neglect to take advantage of the benefits of thermal mass. According to the Thermal Mass Handbook ASHRAE/IES Standard 90.1:
" Thermal Mass is a property that enables building materials to absorb, store, and later release significant amounts of heat.
Buildings constructed of concrete and masonry have a unique energy saving advantage because of their inherent thermal mass.
These materials absorb energy slowly and hold it for much longer periods of time than do less massive materials.
This delays and reduces heat transfer through a thermal mass
building component, leading to three important results:
First, there are fewer spikes in the heating and cooling requirements, since mass slows the response time and moderates indoor temperature fluctuations.
Second, a massive building uses less energy than a similar low mass building due to the reduced heat transfer through the massive elements.
Three, thermal mass can shift energy demand to off peak time periods when utility rates are lower.
To best moderate indoor temperature, the thermal mass should be exposed to the interior, conditioned air and insulated from outdoor temperature variations.
R-values and U-values do not take into account the effects of thermal mass, and by themselves, are inadequate in describing the heat transfer properties of the construction assemblies with significant amounts of thermal mass.
Typically, an additional property called heat capacity (HC) is used to more accurately characterize wall construction with thermal mass."
Isolated Thermal Mass
Most buildings constructed today exhibit isolated thermal mass ,where the insulation separates the interior air from the thermal mass of the wall. This negates the benefits of thermal mass.
Both old and new technology thus incorporate old habits and traditions and contribute to wasting millions of barrels of oil annually.
Examine one emerging technology, the Insulated Concrete Form (ICF). Concrete is poured between two rigid expanded polystyrene (EPS) forms, creating a wall that has high R-value, but has isolated thermal mass.
The ICF industry claims that ICF’s high R-value relative to wood frame construction makes ICF’s an energy efficient alternative. That is true, but ICF’s isolated thermal mass negates the effect of the high thermal mass inherent in the isolated concrete portion of the wall, and misses the opportunity to exploit the wall’s stored energy.
(Additionally, ICF’s have environmental issues associated with flame retardant. While the concrete is fireproof, the EPS contains a flame retardant that emits toxic fumes when burned. Although occupants of a burning ICF building may escape the premises, the firefighters responding to the call, as well as people in the immediate environment around the building, may be exposed to toxic gases caused by the flame retardant.)
Similarly, other high R-value materials, like Structural Insulated Panels (SIPS), create airtight and relatively energy-efficient building envelopes. SIPS have negligible thermal mass, however, and airtight buildings require HVAC energy to maintain indoor air quality.
Insulated Thermal Mass
Composite masonry walls offer the best opportunity to exploit thermal mass.
Energy efficient design for composite walls features a backup block, separated from the outside wall of brick veneer by an EPS insert. This creates insulated thermal mass, the key to reducing the global carbon footprint. The interior wall is essentially a building within a building, and acts as a giant energy storage battery.
There are drawbacks to traditional double wythe composite wall construction. The first is that the mason has to lay the wall twice, which adds substantial labor cost to the job. The second is that the connectors between the inner and outer walls can exhibit thermal bridging, which reduces the energy efficiency of the wall. Also, the connectors can corrode over time, reducing the structural integrity of the wall.
Single Wythe Insulated Thermal Mass
Insulated concrete block is a relatively new technology which creates insulated thermal mass in a single wythe environment. Insulated block features an EPS continuous thermal barrier which separates the interior and exterior portions of the block.
The insulated thermal mass consistently delivers whole-building HVAC energy consumption savings of over 60%, compared to standard building methods and materials, using the US Department of Energy Commercial Buildings Energy Consumption Survey figures as a baseline.
Energy savings translates into construction savings, as lower capacity HVAC systems can be used in insulated block buildings.
Over seventy buildings erected in the last fifteen years prove the cost efficiency and energy efficiency inherent in the technology.
Insulated concrete blocks are compatible with the major green building initiatives, including Leadership in Energy and Environmental Design (LEED), Green Globe, Green Building Initiative (GBI), and Collaborative for High Performance Schools (CHPS).
Aesthetically, insulated half-high and full height block with architectural finishes offers designers expanded options.
Structurally, insulated block buildings feature all of the benefits of masonry construction, as they are fireproof, durable, safe, secure, and maintenance free. They add energy efficiency, noise reduction, and return on investment.
In fact, insulated concrete blocks pay for themselves through energy savings, and can contribute mightily toward reducing the global carbon footprint of both residential and non-residential buildings.
May form (for)ever follow function.
NRG guy
For more information on insulated concrete block, visit www.nrginsulatedblock.com .
For spam, this is very articulate. but it is still spam...
nrgguy
Feb 6, 10 11:16 am
Excuse me, But I thought the purpose of a forum like this was to enlighten people on a topic relevant to the industry. Does it constitute spam, just because there is a link for further information? Is it spam because someone with a vested interest wrote it? (Then almost all of what is written can be discounted.)
The bottom line is, that architects, who should know better, continue to put the insulation on the wrong side of the wall.
The article points this out,and offers a solution.To get slammed as spam for bringing this up is more than a little unfair.
Did anyone find this article helpful?
ff33ยบ
Feb 6, 10 11:32 am
Marty,
By our standards , this is definitely spam.
Yet, I will say that I find the product you are pushing interesting though. ]
Generally speakling, it seems like there are disproportionately more permutations on the concrete + foam combination than any other in the building industry....icf, roster block...so many ideas. Just googling "concrete and foam" yields a lot of flexiblity and creativity with this combination.
vado retro
Feb 6, 10 11:44 am
if i hear another misattribution of sullivan's quote, i may artistically consider defenestrating myself from the nearest tall office building.
nrgguy
Feb 6, 10 12:56 pm
The quotes are from a book that attributes the quotes to Sullivan.
I attributed the quotes to Sullivan, since the aurhor claimed that these were actually Sullivan's words.
I wasn't in the room, and I sincerely apologize to anyone that was (even if they are very, very, very old).
holz.box
Feb 6, 10 1:36 pm
airtight buildings require HVAC energy to maintain indoor air quality.
superinsulated, airtight buildings require nominal energy for heating or cooling, as do most thermal mass-utilizing projects.
contribute mightily toward reducing the global carbon footprint of both residential and non-residential buildings.
yes, if you don't account for the PEI of both EPS and cement...
but i'm still confused about the form/function aspect you are plugging - changing the block doesn't change the form of a building - it just changes the function of the block. the same fugly wall (CMU - banal) is still getting thrown up.
montagneux
Feb 6, 10 2:10 pm
When I like to add good thermal mass and good insulation to my projects... i prefer using 2 foot thick granite slabs with a good 1" thick silver plated zinc sheets behind 1/8" thick gold foil.
On the interior, I like foot thick beam walls with blown in down and pashmere batting with standard gypsum board. For extra airtight quality, I like to use exaggerated alabaster moldings with silk upholstered, down stuff paneling.
Of course, I don't like to use unsightly ventilation... So, I prefer to have bronze statues heated and chilled and moved around the property hand fanned by Malawian orphaned children.
88Buildings
Nov 8, 18 4:27 pm
I love it !!!
nrgguy
Feb 6, 10 4:55 pm
About the form/function, if a building's function is to be energy efficient, the form should be infused with energy efficient design and materials. Half-high CMU's that look like brick have lower-than-brick embodied energy, can contain recycled content, and have a number of different finishes. This is not your grandmother's CMU we are talking about. This is stuff that is GreenSpec listed.
I do like the bronze statue idea. What is the Thermal Time Constant of a life size bronze statue of Shaq the b-ball player?
vado retro
Feb 6, 10 6:24 pm
misinterpretation. my bad.
snook_dude
Feb 6, 10 7:47 pm
i'm just waiting for someone to come out with a Green Shag Carpet in day-glo orange. Which is a super insulator to be used in multiple applications...floor covering wall covering toilet covers....the works.
holz.box
Feb 6, 10 10:48 pm
again, i don't get what you're trying to say re: form following function. the form of the building isn't changing just because a slightly greener CMU is used.
also, CMU doesn't have enough of a thermal mass, especially if 1/4 of the mass is outside the insulation. sure, it's got more mass than a wood wall, but to really be effective for thermal mass, we'd have to grout the CMU...
snook,
carpet works against thermal mass! rip it out!
nrgguy
Feb 7, 10 11:12 am
About form following function, I am referring to insulated thermal mass vs. isolated thermal mass, a configuration that maximizes the thermal time constant, which is a measure of a wall's thermal performance, vs. one that does not.
In that sense, form will change, because the form is now a building in its energy efficient form, as opposed to its less than energy efficient form.
Here is a link that explains the thermal time constatnt. Slides 7 & 8 are excellent. www.solarenergynews.net/BioClimaticDesign/Mass/Thermal.ppt
A CMU with insulated thermal mass actually does have enough thermal mass to deliver 60% HVAC energy savings. Think about that relative to reducing the overall global footprint. It makes it a lot easier to get to A-2030 when you lop 60% off the top of the HVAC, which is about 30% of whole building energy.
There is research that actually indicates that there may be diminishing returns as the thickness of the thermal mass increases, as it takes longer to load the system with energy. In any event, yes, grout improves the energy efficiency of an insulated thermal mass configuration.
I know you guys want to make things like Aqua in Chicago, and that's as it should be. But, for the institutional and commercial, even residential, buildings that are traditional masonry structures, which means safe, secure, durable, long lasting, low maintenance, and fireproof, one would think that energy efficiency should be an overarching design consideration.
The most cost effective way to produce energy efficiency in the above application is with an insulated cmu with a continuous thermal barrier.
Until someone proves otherwise.
holz.box
Feb 7, 10 2:46 pm
again, the form isn't changing because of the nrg block.
now, i can say i want an energy efficient building and make it boxy w no re-entrant corners and a compact shape - this would be form responding to your definition of function.
The most cost effective way to produce energy efficiency in the above application is with an insulated cmu with a continuous thermal barrier.
i'm going to have a much more cost effective and energy efficient house w/ correct solar orientation, modified larsen truss, super insulated w/ cellulose and airtight (meeting passive house standards) - as well as literally having no heating bill and significantly less PEI (primary embodied input).
which shows the specific heat of a 8" concrete wall (HC=19.2) @ over twice the HC than a medium weight, non-grouted 6" CMU (HC=8.9)
wood actually has a high specific heat - one of the many reasons the prefab cross laminated panels used throughout much of central europe are so highly prized. and looks significantly better.
nrgguy
Feb 7, 10 3:26 pm
Wood may have a high specific heat, but it does not have the thermal performance of the insulated thermal mass of an insulated cmu, it is not maintenance free, or as durable, certainly not as fireproof, which all relate to cost and energy efficiency.
I am not saying that adding grout does not increase heat capacity, as obviously it does.
Heat capacity, along with thermal lag time, are key attributes of the insulated cmu system.
Super insulated structures, air tight structures, still need ventilation, and that requires energy. It is like a styrofoam cooler. The contents inside stay warm, but he styro itself holds no energy. That is my only point.
I do not believe there is a more energy and cost efficient (long term) way to go than with the insulated cmu.
Thanks everyone, for your input. As a first time poster, this has been an enlightening weekend.
Back to work.
sharkswithlasers
Feb 7, 10 4:55 pm
nrgguy -- what material are the ties made of that connect the wythes of concrete together across the insulation?
nrgguy
Feb 7, 10 10:06 pm
The EPS insert and block components use a modified dovetail design that holds the two concrete units together. In case of fire, where the EPS would melt, the wall would not come apart.( As an aside, the EPS is not exposed to flame, so there is no need for flame retardant.)
sharkswithlasers
Feb 8, 10 7:31 am
Really a very interesting product, nrgguy -- can you give any cost info / comparisons? ...also, any details you could post re: the top of wall condition you'd recommend? That is, since the inside wythe isn't load bearing, how is the insulation kept continuous with no thermal bridging where the wall meets the roof and roof insulation?
nrgguy
Feb 8, 10 9:20 am
Price varies by the manufacturer. We had a woman in Houston act as her own contractor in 2003, and she used 12" split face, and her cost per sq ft installed was under $16. I wish I knew how to post pics here, and I would show you what this castle looks like. You can find them on the web site.She has ridden out a couple hurricanes in it already.
If you assume thirty percent rise in price since then, it should come in at under $21. Compare to the MACONLINE (Chicago) price for a cavity wall, which is well over thirty.
There are engineering drawings at www.nrginsulatedblock.com The interior (block) wythe is loadbearing , is that what you were referring to?
There will be points of thermal bridging, as in corners, windows, expansion joints, roof, etc., but they do not significantly hinder the energy performance of the wall. Also, standard blocks are used for the base course, since the cavities are larger and more suited as moisture resevoirs.
The true measure of a building's energy efficiency is the utility bill, and that is where this block consistently delivers over 60% HVAC energy savings, compared to same-sized standard block building (interior insulation, isolated thermal mass), using DOE Commerical Building Energy Consumption Survey as a baseline reference. If I knew how to tie that in to the ASHRAE 90.1 2007, it would greatly enhance the ability to forecast LEED points/ performance.
(I am not an engineer or an architect. My two master's degrees are in the communications field.)
snook_dude
Feb 8, 10 5:32 pm
n.....can you explain how you can achieve and r-22 with what appears to be 2" of expanded polystyrene insulation, as a thermal break? in some of the photos it even looks like it is less than 2 feet. That is unless your using "Therma blok" areogel in lieu of expanded polystyrene insulation.
Then once again the thermal break does not happen at those 3/8"
joints every 8"... so is it really possible to obtain an r-22 with the product you are touting?
nrgguy
Feb 8, 10 11:02 pm
snook,
the independent lab report is available in its entirety on the website. It takes a minute to download. The lab scientists used a DOE approved computer simulation to arrive at the conclusions.
snook_dude
Feb 9, 10 7:05 pm
nrgguy....was that independent lab on the up and up? It all looks suspect to me wonder if another independent lab would come to the same conclusions? I can't see how you can push the R-value as much as they indicate. If you were to tell me R-10 I might take the bait, cause that is alot better performance than a cmu block.
nrgguy...I live in an old stone house so I have a pretty good idea of the thermal dynamics of what actually happens in the field with the temperature variations. On a sunny day our house stays comfortable, but when the sun is not out in New England it can get
not so comfortable and the furnace runs alot more often.
nrgguy
Feb 9, 10 11:07 pm
snook,
I believe the lab is legitimate. Even if it was not, the r-value is just a small part of the thermal performance of an insulated thermal mass set up. It is the high heat capacity and thermal lag time, along with the thermal barrier, that makes NRG so efficient.
Ultimately, the true measure, and truest test, of NRG wall performance comes in the mail once a month, as a utility bill. You just cannot refute the amount of savings, no matter how it works.
snook_dude
Feb 10, 10 8:50 am
guy: there seems to be so much slight of hand in the market place today as to the "Green Thing" It is add companies dream come true.
Show me the meat, you have some utility bills?
nrgguy
Feb 10, 10 9:49 am
snook, I personally have seen and verified savings through utlility bills on a number of buildings. The savings are real.
snook_dude
Feb 10, 10 9:58 am
The independent lab does not exist Energy Management Inc.
What is with Robert J. Bond Jr. ? His qualifications say he is a member of the American Meterological Society? What does that have to do with testing?
nrgguy
Feb 10, 10 10:38 am
Energy Management was in business, as you can tell by the repoprt, at the time the report was done. That it is no longer in business does not affect the thermal performance of NRG block.
I guess all I can say at this point is "try it, you'll like it", as have 70 plus building owners.
Form (hardly) ever follows function : integrating thermal mass.
The words of the late American architect Louis Henry Sullivan point to the heart of green and sustainable design:
"It is the pervading law of all things organic, and inorganic,
of all things physical and metaphysical,
of all things human and all things super-human,
of all true manifestations of the head, of the heart, of the soul, that the life is recognizable in its expression, that form ever follows function. This is the law.”
Also,
“All practical demands of utility should be paramount as basis of planning and design; ...no architectural dictum, or tradition, or superstition, or habit should stand in the way."
The first quote states that things take a certain shape because they perform a certain function. The second reminds architects and engineers to base design on function. Tradition and habits that impede utility should be excised.
These concepts offer a strong foundation for the green building and sustainable design movement. The words “green” and “sustainable” refer to energy efficient and environmentally responsible materials and methods that can be employed without harming future generations.
Accordingly, buildings should take the form of structures that maximize energy efficiency, exhibit green and sustainable design elements, and facilitate the activities specific to the space.
Maximizing Energy Efficiency
Architects and engineers have an opportunity to establish new habits and traditions which transform design features into maximum energy efficiency.
Consider the building envelope, which can represent the largest area of energy consumption or conservation. If maximum energy efficiency is a priority function of a new building, then it is accurate to state that, currently, form (hardly) ever follows function.
Why? Because most buildings neglect to take advantage of the benefits of thermal mass. According to the Thermal Mass Handbook ASHRAE/IES Standard 90.1:
" Thermal Mass is a property that enables building materials to absorb, store, and later release significant amounts of heat.
Buildings constructed of concrete and masonry have a unique energy saving advantage because of their inherent thermal mass.
These materials absorb energy slowly and hold it for much longer periods of time than do less massive materials.
This delays and reduces heat transfer through a thermal mass
building component, leading to three important results:
First, there are fewer spikes in the heating and cooling requirements, since mass slows the response time and moderates indoor temperature fluctuations.
Second, a massive building uses less energy than a similar low mass building due to the reduced heat transfer through the massive elements.
Three, thermal mass can shift energy demand to off peak time periods when utility rates are lower.
To best moderate indoor temperature, the thermal mass should be exposed to the interior, conditioned air and insulated from outdoor temperature variations.
R-values and U-values do not take into account the effects of thermal mass, and by themselves, are inadequate in describing the heat transfer properties of the construction assemblies with significant amounts of thermal mass.
Typically, an additional property called heat capacity (HC) is used to more accurately characterize wall construction with thermal mass."
Isolated Thermal Mass
Most buildings constructed today exhibit isolated thermal mass ,where the insulation separates the interior air from the thermal mass of the wall. This negates the benefits of thermal mass.
Both old and new technology thus incorporate old habits and traditions and contribute to wasting millions of barrels of oil annually.
Examine one emerging technology, the Insulated Concrete Form (ICF). Concrete is poured between two rigid expanded polystyrene (EPS) forms, creating a wall that has high R-value, but has isolated thermal mass.
The ICF industry claims that ICF’s high R-value relative to wood frame construction makes ICF’s an energy efficient alternative. That is true, but ICF’s isolated thermal mass negates the effect of the high thermal mass inherent in the isolated concrete portion of the wall, and misses the opportunity to exploit the wall’s stored energy.
(Additionally, ICF’s have environmental issues associated with flame retardant. While the concrete is fireproof, the EPS contains a flame retardant that emits toxic fumes when burned. Although occupants of a burning ICF building may escape the premises, the firefighters responding to the call, as well as people in the immediate environment around the building, may be exposed to toxic gases caused by the flame retardant.)
Similarly, other high R-value materials, like Structural Insulated Panels (SIPS), create airtight and relatively energy-efficient building envelopes. SIPS have negligible thermal mass, however, and airtight buildings require HVAC energy to maintain indoor air quality.
Insulated Thermal Mass
Composite masonry walls offer the best opportunity to exploit thermal mass.
Energy efficient design for composite walls features a backup block, separated from the outside wall of brick veneer by an EPS insert. This creates insulated thermal mass, the key to reducing the global carbon footprint. The interior wall is essentially a building within a building, and acts as a giant energy storage battery.
There are drawbacks to traditional double wythe composite wall construction. The first is that the mason has to lay the wall twice, which adds substantial labor cost to the job. The second is that the connectors between the inner and outer walls can exhibit thermal bridging, which reduces the energy efficiency of the wall. Also, the connectors can corrode over time, reducing the structural integrity of the wall.
Single Wythe Insulated Thermal Mass
Insulated concrete block is a relatively new technology which creates insulated thermal mass in a single wythe environment. Insulated block features an EPS continuous thermal barrier which separates the interior and exterior portions of the block.
The insulated thermal mass consistently delivers whole-building HVAC energy consumption savings of over 60%, compared to standard building methods and materials, using the US Department of Energy Commercial Buildings Energy Consumption Survey figures as a baseline.
Energy savings translates into construction savings, as lower capacity HVAC systems can be used in insulated block buildings.
Over seventy buildings erected in the last fifteen years prove the cost efficiency and energy efficiency inherent in the technology.
Insulated concrete blocks are compatible with the major green building initiatives, including Leadership in Energy and Environmental Design (LEED), Green Globe, Green Building Initiative (GBI), and Collaborative for High Performance Schools (CHPS).
Aesthetically, insulated half-high and full height block with architectural finishes offers designers expanded options.
Structurally, insulated block buildings feature all of the benefits of masonry construction, as they are fireproof, durable, safe, secure, and maintenance free. They add energy efficiency, noise reduction, and return on investment.
In fact, insulated concrete blocks pay for themselves through energy savings, and can contribute mightily toward reducing the global carbon footprint of both residential and non-residential buildings.
May form (for)ever follow function.
NRG guy
For more information on insulated concrete block, visit www.nrginsulatedblock.com .
Marty Walters
[email protected]
For spam, this is very articulate. but it is still spam...
Excuse me, But I thought the purpose of a forum like this was to enlighten people on a topic relevant to the industry. Does it constitute spam, just because there is a link for further information? Is it spam because someone with a vested interest wrote it? (Then almost all of what is written can be discounted.)
The bottom line is, that architects, who should know better, continue to put the insulation on the wrong side of the wall.
The article points this out,and offers a solution.To get slammed as spam for bringing this up is more than a little unfair.
Did anyone find this article helpful?
Marty,
By our standards , this is definitely spam.
Yet, I will say that I find the product you are pushing interesting though. ]
Generally speakling, it seems like there are disproportionately more permutations on the concrete + foam combination than any other in the building industry....icf, roster block...so many ideas. Just googling "concrete and foam" yields a lot of flexiblity and creativity with this combination.
if i hear another misattribution of sullivan's quote, i may artistically consider defenestrating myself from the nearest tall office building.
The quotes are from a book that attributes the quotes to Sullivan.
I attributed the quotes to Sullivan, since the aurhor claimed that these were actually Sullivan's words.
I wasn't in the room, and I sincerely apologize to anyone that was (even if they are very, very, very old).
superinsulated, airtight buildings require nominal energy for heating or cooling, as do most thermal mass-utilizing projects.
contribute mightily toward reducing the global carbon footprint of both residential and non-residential buildings.
yes, if you don't account for the PEI of both EPS and cement...
but i'm still confused about the form/function aspect you are plugging - changing the block doesn't change the form of a building - it just changes the function of the block. the same fugly wall (CMU - banal) is still getting thrown up.
When I like to add good thermal mass and good insulation to my projects... i prefer using 2 foot thick granite slabs with a good 1" thick silver plated zinc sheets behind 1/8" thick gold foil.
On the interior, I like foot thick beam walls with blown in down and pashmere batting with standard gypsum board. For extra airtight quality, I like to use exaggerated alabaster moldings with silk upholstered, down stuff paneling.
Of course, I don't like to use unsightly ventilation... So, I prefer to have bronze statues heated and chilled and moved around the property hand fanned by Malawian orphaned children.
I love it !!!
About the form/function, if a building's function is to be energy efficient, the form should be infused with energy efficient design and materials. Half-high CMU's that look like brick have lower-than-brick embodied energy, can contain recycled content, and have a number of different finishes. This is not your grandmother's CMU we are talking about. This is stuff that is GreenSpec listed.
I do like the bronze statue idea. What is the Thermal Time Constant of a life size bronze statue of Shaq the b-ball player?
misinterpretation. my bad.
i'm just waiting for someone to come out with a Green Shag Carpet in day-glo orange. Which is a super insulator to be used in multiple applications...floor covering wall covering toilet covers....the works.
again, i don't get what you're trying to say re: form following function. the form of the building isn't changing just because a slightly greener CMU is used.
also, CMU doesn't have enough of a thermal mass, especially if 1/4 of the mass is outside the insulation. sure, it's got more mass than a wood wall, but to really be effective for thermal mass, we'd have to grout the CMU...
snook,
carpet works against thermal mass! rip it out!
About form following function, I am referring to insulated thermal mass vs. isolated thermal mass, a configuration that maximizes the thermal time constant, which is a measure of a wall's thermal performance, vs. one that does not.
In that sense, form will change, because the form is now a building in its energy efficient form, as opposed to its less than energy efficient form.
Here is a link that explains the thermal time constatnt. Slides 7 & 8 are excellent.
www.solarenergynews.net/BioClimaticDesign/Mass/Thermal.ppt
A CMU with insulated thermal mass actually does have enough thermal mass to deliver 60% HVAC energy savings. Think about that relative to reducing the overall global footprint. It makes it a lot easier to get to A-2030 when you lop 60% off the top of the HVAC, which is about 30% of whole building energy.
There is research that actually indicates that there may be diminishing returns as the thickness of the thermal mass increases, as it takes longer to load the system with energy. In any event, yes, grout improves the energy efficiency of an insulated thermal mass configuration.
I know you guys want to make things like Aqua in Chicago, and that's as it should be. But, for the institutional and commercial, even residential, buildings that are traditional masonry structures, which means safe, secure, durable, long lasting, low maintenance, and fireproof, one would think that energy efficiency should be an overarching design consideration.
The most cost effective way to produce energy efficiency in the above application is with an insulated cmu with a continuous thermal barrier.
Until someone proves otherwise.
again, the form isn't changing because of the nrg block.
now, i can say i want an energy efficient building and make it boxy w no re-entrant corners and a compact shape - this would be form responding to your definition of function.
The most cost effective way to produce energy efficiency in the above application is with an insulated cmu with a continuous thermal barrier.
i'm going to have a much more cost effective and energy efficient house w/ correct solar orientation, modified larsen truss, super insulated w/ cellulose and airtight (meeting passive house standards) - as well as literally having no heating bill and significantly less PEI (primary embodied input).
for those interested, here is a link to specific heat of CMU/concrete via conc. masonry inst. of CA/NV
which shows the specific heat of a 8" concrete wall (HC=19.2) @ over twice the HC than a medium weight, non-grouted 6" CMU (HC=8.9)
wood actually has a high specific heat - one of the many reasons the prefab cross laminated panels used throughout much of central europe are so highly prized. and looks significantly better.
Wood may have a high specific heat, but it does not have the thermal performance of the insulated thermal mass of an insulated cmu, it is not maintenance free, or as durable, certainly not as fireproof, which all relate to cost and energy efficiency.
I am not saying that adding grout does not increase heat capacity, as obviously it does.
Heat capacity, along with thermal lag time, are key attributes of the insulated cmu system.
Super insulated structures, air tight structures, still need ventilation, and that requires energy. It is like a styrofoam cooler. The contents inside stay warm, but he styro itself holds no energy. That is my only point.
I do not believe there is a more energy and cost efficient (long term) way to go than with the insulated cmu.
Thanks everyone, for your input. As a first time poster, this has been an enlightening weekend.
Back to work.
nrgguy -- what material are the ties made of that connect the wythes of concrete together across the insulation?
The EPS insert and block components use a modified dovetail design that holds the two concrete units together. In case of fire, where the EPS would melt, the wall would not come apart.( As an aside, the EPS is not exposed to flame, so there is no need for flame retardant.)
Really a very interesting product, nrgguy -- can you give any cost info / comparisons? ...also, any details you could post re: the top of wall condition you'd recommend? That is, since the inside wythe isn't load bearing, how is the insulation kept continuous with no thermal bridging where the wall meets the roof and roof insulation?
Price varies by the manufacturer. We had a woman in Houston act as her own contractor in 2003, and she used 12" split face, and her cost per sq ft installed was under $16. I wish I knew how to post pics here, and I would show you what this castle looks like. You can find them on the web site.She has ridden out a couple hurricanes in it already.
If you assume thirty percent rise in price since then, it should come in at under $21. Compare to the MACONLINE (Chicago) price for a cavity wall, which is well over thirty.
There are engineering drawings at www.nrginsulatedblock.com The interior (block) wythe is loadbearing , is that what you were referring to?
There will be points of thermal bridging, as in corners, windows, expansion joints, roof, etc., but they do not significantly hinder the energy performance of the wall. Also, standard blocks are used for the base course, since the cavities are larger and more suited as moisture resevoirs.
The true measure of a building's energy efficiency is the utility bill, and that is where this block consistently delivers over 60% HVAC energy savings, compared to same-sized standard block building (interior insulation, isolated thermal mass), using DOE Commerical Building Energy Consumption Survey as a baseline reference. If I knew how to tie that in to the ASHRAE 90.1 2007, it would greatly enhance the ability to forecast LEED points/ performance.
(I am not an engineer or an architect. My two master's degrees are in the communications field.)
n.....can you explain how you can achieve and r-22 with what appears to be 2" of expanded polystyrene insulation, as a thermal break? in some of the photos it even looks like it is less than 2 feet. That is unless your using "Therma blok" areogel in lieu of expanded polystyrene insulation.
Then once again the thermal break does not happen at those 3/8"
joints every 8"... so is it really possible to obtain an r-22 with the product you are touting?
snook,
the independent lab report is available in its entirety on the website. It takes a minute to download. The lab scientists used a DOE approved computer simulation to arrive at the conclusions.
nrgguy....was that independent lab on the up and up? It all looks suspect to me wonder if another independent lab would come to the same conclusions? I can't see how you can push the R-value as much as they indicate. If you were to tell me R-10 I might take the bait, cause that is alot better performance than a cmu block.
nrgguy...I live in an old stone house so I have a pretty good idea of the thermal dynamics of what actually happens in the field with the temperature variations. On a sunny day our house stays comfortable, but when the sun is not out in New England it can get
not so comfortable and the furnace runs alot more often.
snook,
I believe the lab is legitimate. Even if it was not, the r-value is just a small part of the thermal performance of an insulated thermal mass set up. It is the high heat capacity and thermal lag time, along with the thermal barrier, that makes NRG so efficient.
Ultimately, the true measure, and truest test, of NRG wall performance comes in the mail once a month, as a utility bill. You just cannot refute the amount of savings, no matter how it works.
guy: there seems to be so much slight of hand in the market place today as to the "Green Thing" It is add companies dream come true.
Show me the meat, you have some utility bills?
snook, I personally have seen and verified savings through utlility bills on a number of buildings. The savings are real.
The independent lab does not exist Energy Management Inc.
What is with Robert J. Bond Jr. ? His qualifications say he is a member of the American Meterological Society? What does that have to do with testing?
Energy Management was in business, as you can tell by the repoprt, at the time the report was done. That it is no longer in business does not affect the thermal performance of NRG block.
I guess all I can say at this point is "try it, you'll like it", as have 70 plus building owners.