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radiant insulation
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| SQLit 2006-02-19, 12:21 pm |
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"John & / or Maryln" <schnahz@thisaintme.net> wrote in message
news:43f878ec$0$25086$1e6826b@news.chesco.com...
> Hi All,
> Would appreciate opinions on foil insulation. Here is where I
> started. http://www.radiantbarrier.com/physics_of_foil.htm
>
> Thanks, john
Most of the claims are just that. Call your utility and see what they
recommend. I would want the name and number of any contractor that they
recommend. Please post it here.
The government pages I have been to do not list radiant foils as a method of
insulation.
Insulation works cause there is trapped air in it. The more volume the
better the insulation.
Fiberglass, and cellulous are the ones used by the home builders. Rock wool
not so much now days. So what is a couple of inches of Mylar doing to trap?
Ahh you say but what about the radiant energy? I say bunk...
If this stuff really worked, then why are the new home builders using it?
Could it be that there are alternatives for less money? Or will FHA even
accept this product? Tyvek the house wrap was not instantly accepted in the
beginning. These claims have been around for 10 years, obviously some one
is keeping the industry alive.
Why would you be worried about radiant heat anyway? If you have good
insulation above the ceiling it is not a problem.
I added R-30, about 8 inches, of cellulous to my attic last July, cost
~$245. I signed a check. August's a/c bill was 50% less than July. I live
in the southwest desert.
| |
| Derek Broughton 2006-02-19, 2:21 pm |
| SQLit wrote:
> "John & / or Maryln" <schnahz@thisaintme.net> wrote in message
> news:43f878ec$0$25086$1e6826b@news.chesco.com...
>
> Most of the claims are just that.
Having used reflective mylar "space blankets" for personal use, I can't see
why a foil shouldn't work on a house. I use one on my unheated waterbed.
It doesn't stop the bladder from cooling down, but it prevents the
temperature of the bladder from cooling _me_.
> Insulation works cause there is trapped air in it. The more volume the
> better the insulation.
> Fiberglass, and cellulous are the ones used by the home builders. Rock
> wool not so much now days.
ime, the problem with rock wool has nothing to do with insulative ability
and everything to do with availability (which, in turn, is limited because
of shipping costs). I did my entire last house in Roxul, but it's
unavailable here because you can get 2-3 times as much fiberglass
insulation in a truck to send it out here (Rock wool basically doesn't
compress).
> So what is a couple of inches of Mylar doing to
> trap? Ahh you say but what about the radiant energy? I say bunk...
>
> If this stuff really worked, then why are the new home builders using it?
I think that must have been "why aren't..."?
> Why would you be worried about radiant heat anyway?
Because all heat loss is radiant?
--
derek
| |
| daestrom 2006-02-19, 2:21 pm |
|
"John & / or Maryln" <schnahz@thisaintme.net> wrote in message
news:43f878ec$0$25086$1e6826b@news.chesco.com...
> Hi All,
> Would appreciate opinions on foil insulation. Here is where I
> started. http://www.radiantbarrier.com/physics_of_foil.htm
>
Radiant insulation *can* work, in very specific circumstances. But most of
the claims are over-inflated and don't really reflect 'typical' performance.
The DOE has done some studies with these and came to same conclusions.
Trying to assess its performance by claiming some 'R' value is usually
useless. Manufacturers set up the most promising conditions, measure the
performance and publish the 'R' value that would correspond to that. But
other operating conditions can cut the effective 'R' by a factor of five.
The radiant surface must *not* be in direct contact with other material on
one side. It is important to be able to fasten it *under* the rafters in an
attic, *not* over the flooring (dust accumulation can make the foil about
useless in just a couple of years if allowed to accumulate).
Most homes lose a lot of their heat via convection and foil doesn't stop
that. It can keep an attic cooler in summer to help A/C costs.
daestrom
| |
| Harry Chickpea 2006-02-19, 3:21 pm |
| "daestrom" <daestrom@NO_SPAM_HEREtwcny.rr.com> wrote:
>Most homes lose a lot of their heat via convection and foil doesn't stop
>that. It can keep an attic cooler in summer to help A/C costs.
Unless there is a continuous ridge vent, this can be counterproductive
by shortening the life of the roof and increasing roof replacement
costs. Excess heat vaporizes the volitiles out of the roofing paper
and shingles.
| |
| Anthony Matonak 2006-02-19, 4:21 pm |
| Harry Chickpea wrote:
> "daestrom" <daestrom@NO_SPAM_HEREtwcny.rr.com> wrote:
>
>
> Unless there is a continuous ridge vent, this can be counterproductive
> by shortening the life of the roof and increasing roof replacement
> costs. Excess heat vaporizes the volitiles out of the roofing paper
> and shingles.
What if you don't have tar-paper shingles? I've heard both clay
and metal roofing products are popular.
Anthony
| |
| Harry Chickpea 2006-02-19, 5:21 pm |
| Anthony Matonak <anthonym40@nothing.like.comcast.net> wrote:
>Harry Chickpea wrote:
>
>What if you don't have tar-paper shingles? I've heard both clay
>and metal roofing products are popular.
>
>Anthony
Roofing tiles (clay or cement) have a waterproof membrane of roll
roofing underneath, so the same would follow there. Metal might not,
but I've never torn a metal roof apart.
| |
| Solar Flare 2006-02-19, 6:21 pm |
| Metal sheeting or stripping = about $ 2-3 times good
asphalt shingles.
Metal shingles for a better look = $ 4-5 times good
asphalt shingles.
"Anthony Matonak" <anthonym40@nothing.like.comcast.net>
wrote in message
news:5Midnbjfr_2RUGXeRVn-vw@comcast.com...
> Harry Chickpea wrote:
wrote:[color=darkred]
and foil doesn't stop[color=darkred]
help A/C costs.[color=darkred]
be counterproductive[color=darkred]
roof replacement[color=darkred]
the roofing paper[color=darkred]
>
> What if you don't have tar-paper shingles? I've heard
both clay
> and metal roofing products are popular.
>
> Anthony
| |
|
| Harry Chickpea wrote:
> "daestrom" <daestrom@NO_SPAM_HEREtwcny.rr.com> wrote:
>
>
>
>
> Unless there is a continuous ridge vent, this can be counterproductive
> by shortening the life of the roof and increasing roof replacement
> costs. Excess heat vaporizes the volitiles out of the roofing paper
> and shingles.
Cite? Everything I've read suggests that's an urban legend (probably
because any increase in temperature is small compared with the normal
situation). So I'd like to see an actual study if you know of one.
--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form che...@prodigy.net.
| |
| Harry Chickpea 2006-02-19, 8:21 pm |
| CJT <abujlehc@prodigy.net> wrote:
>Harry Chickpea wrote:
>
>
>Cite? Everything I've read suggests that's an urban legend (probably
>because any increase in temperature is small compared with the normal
>situation). So I'd like to see an actual study if you know of one.
This is one where I go by my own real world experience and extrapolate
from that. I live in South Florida and had to replace a cement tile
over roll roofing roof a few years back. I replaced it with a
shingle roof, and during the summer months I water that roof to cool
it with an automatic system sprinkler four times a day. I also have
turbine vents. When hurricane Wilma came through, over half my
neighbors lost shingles and had leaks. I lost about six shingle ends
where the wind was funneled, but other than that had no roof damage.
I attribute it to the shingles not being dried out and ready to split
and lift. When I walk on the roof, the shingles are still supple,
unlike other roofs that have been around for a few years.
There is no way that I would intentionally increase the heat load on
my shingles.
| |
|
| Harry Chickpea wrote:
> CJT <abujlehc@prodigy.net> wrote:
>
>
>
>
> This is one where I go by my own real world experience and extrapolate
> from that. I live in South Florida and had to replace a cement tile
> over roll roofing roof a few years back. I replaced it with a
> shingle roof, and during the summer months I water that roof to cool
> it with an automatic system sprinkler four times a day. I also have
> turbine vents. When hurricane Wilma came through, over half my
> neighbors lost shingles and had leaks. I lost about six shingle ends
> where the wind was funneled, but other than that had no roof damage.
> I attribute it to the shingles not being dried out and ready to split
> and lift. When I walk on the roof, the shingles are still supple,
> unlike other roofs that have been around for a few years.
>
> There is no way that I would intentionally increase the heat load on
> my shingles.
>
I'd like a reading from a test case which doesn't include watering
the shingles four times a day.
--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form che...@prodigy.net.
| |
| Tony Wesley 2006-02-20, 12:21 am |
|
Harry Chickpea wrote:
>
>[...] I live in South Florida and had to replace a cement tile
> over roll roofing roof a few years back. I replaced it with a
> shingle roof, and during the summer months I water that roof to cool
> it with an automatic system sprinkler four times a day. I also have
> turbine vents. When hurricane Wilma came through, over half my
> neighbors lost shingles and had leaks. I lost about six shingle ends
> where the wind was funneled, but other than that had no roof damage.
Question: how many of your neighbor's had roofs that were older than "a
few years back"?
Over half?
| |
| nicksanspam@ece.villanova.edu 2006-02-20, 3:21 am |
| Harry Chickpea wrote:
>[...] I live in South Florida and had to replace a cement tile
> over roll roofing roof a few years back. I replaced it with a
> shingle roof, and during the summer months I water that roof to cool
> it with an automatic system sprinkler four times a day...
Well, what's a roof for? Snow and steepness aren't factors in Florida.
Wind and dehumidification are. New houses might be happier with flat
EPDM roofs under a few inches of sand or stone, with some water. A few
plants might provide more shade, but the water they evaporate does more
to keep their leaves cool than to keep the house cool.
An airtight Florida house might have a LiCl roofpond under a plastic film
greenhouse to concentrate LiCl during the day and let it absorb water
vapor from the house at night to keep the house cooler and drier.
Nick
| |
| John & / or Maryln 2006-02-20, 8:21 am |
|
"Derek Broughton" <news@pointerstop.ca> wrote in message
news:pllmc3-k8n.ln1@news.pointerstop.ca...
> SQLit wrote:
>
I[color=darkred]
>
> Having used reflective mylar "space blankets" for personal use, I can't
see
> why a foil shouldn't work on a house. I use one on my unheated waterbed.
> It doesn't stop the bladder from cooling down, but it prevents the
> temperature of the bladder from cooling _me_.
>
>
> ime, the problem with rock wool has nothing to do with insulative ability
> and everything to do with availability (which, in turn, is limited because
> of shipping costs). I did my entire last house in Roxul, but it's
> unavailable here because you can get 2-3 times as much fiberglass
> insulation in a truck to send it out here (Rock wool basically doesn't
> compress).
>
it?[color=darkred]
>
> I think that must have been "why aren't..."?
>
>
> Because all heat loss is radiant?
> --
> derek
Admittedly, the idea of a new kind of insulation has it's charms for me. And
when I read that mass insulation just soaks up the heat as much as it can
hold but then it has to give it up whereas the foil bounces those invisible
infrared rays right back at you.Well I'm thrilled, but then when I came to
the bottom line of what percentage of savings I could expect, the numbers
don't seem to correspond to the theory. So ... I think I may play with it as
nitetime window covers, but I'm not ready to bury it behind drywall until I
understand more.
thanks for your
responses,
John,
..
| |
| Harry Chickpea 2006-02-20, 12:21 pm |
| nicksanspam@ece.villanova.edu wrote:
>Harry Chickpea wrote:
>
>
>Well, what's a roof for? Snow and steepness aren't factors in Florida.
>Wind and dehumidification are. New houses might be happier with flat
>EPDM roofs under a few inches of sand or stone, with some water. A few
>plants might provide more shade, but the water they evaporate does more
>to keep their leaves cool than to keep the house cool.
>
>An airtight Florida house might have a LiCl roofpond under a plastic film
>greenhouse to concentrate LiCl during the day and let it absorb water
>vapor from the house at night to keep the house cooler and drier.
>
>Nick
Roof water is sometimes used on commercial structures here. It makes
sense, sort of. Even when cleaned regularly there is algae growth,
making walking on the roof _extremely_ hazardous. You can't use shoes
with cleats because of the possibility of puncturing the membrane.
You also have to be extremely careful when doing even the most basic
electrical work.
LiCL sounds like a good deal at first, but it heats up while absorbing
humidity, which is about the last thing you want if you are trying to
cool down.
| |
| Harry Chickpea 2006-02-20, 12:21 pm |
| "Tony Wesley" <tonywesley@gmail.com> wrote:
>
>Harry Chickpea wrote:
>
>Question: how many of your neighbor's had roofs that were older than "a
>few years back"?
>Over half?
I would guess at about half, but the wind damage didn't happen
according to age of the roof. One of the more damaged roofs was one
that had been replaced after mine, but had dark shingles. Some cement
tile roofs were fine, others were damaged, but most of the clay barrel
tile roofs had at least some damage. I'm not really crowing about how
well my roof held up, I fully expected it to do fine in the CAT 1
storm that we had. I'm more interested to see how it holds up after
another ten years.
| |
| nicksanspam@ece.villanova.edu 2006-02-20, 1:21 pm |
| Harry Chickpea <hchickpeaREMOVEME@hotmail.com> wrote:
>nicksanspam@ece.villanova.edu wrote:
[color=darkred]
>Roof water is sometimes used on commercial structures here. It makes
>sense, sort of. Even when cleaned regularly there is algae growth,
>making walking on the roof _extremely_ hazardous.
Walk on the dry stone, with water underneath.
>LiCL sounds like a good deal at first, but it heats up while absorbing
>humidity, which is about the last thing you want if you are trying to
>cool down.
Let it absorb house water vapor through a ceiling hatch.
Nick
| |
| Harry Chickpea 2006-02-20, 2:21 pm |
| nicksanspam@ece.villanova.edu wrote:
>Harry Chickpea <hchickpeaREMOVEME@hotmail.com> wrote:
>
>
>
>
>Walk on the dry stone, with water underneath.
You can't put stone on the surface without creating more spots for
algae to colonize. Pea stone is even worse. I've seen treated lumber
catwalks used around HVAC units, but these create their own problems.
>
>Let it absorb house water vapor through a ceiling hatch.
So are you suggesting trying to dry the attic? The attics down here
are bone dry anyway from the heat baking out any moisture in the wood.
>Nick
| |
| alecn@houseneeds.com 2006-02-20, 3:21 pm |
| John,
Like any tool foil insulation it needs to be used in the proper
context. What are you trying to achieve?
We use a product call Low-E with great success is many of our radiant
projects. We use it as a thermal break between the slab and the ground.
The aluminum is sandwiched between two sheets of polyethylene foam so
you get a thermal break, vapor barrier, easy to install, and something
that holds up to 93 PSI worth of punding at a job site.
We also use it for radiant under floor applications to reflect the heat
back up a joist bay.
You can see more info here on how we use it for mostly heating
applications:
http://www.houseneeds.com/shop/misc...lationindex.asp
Alec
| |
| Derek Broughton 2006-02-20, 3:21 pm |
| Harry Chickpea wrote:
> LiCL sounds like a good deal at first, but it heats up while absorbing
> humidity, which is about the last thing you want if you are trying to
> cool down.
Refrigerators heat up while they're cooling the contents, too. Surely this
just requires an intelligent design to ensure that heat flows in the right
direction.
--
derek
| |
| Ron Purvis 2006-02-20, 4:21 pm |
| A radiant barrier is primarily helpful in the deep south where you have
almost no heating and a lot of cooling. I live in Greenville, SC and it is a
tremendous help here. The typical household here will use AC daily at least
April to October, whereas the heat will only be used sparely for a couple of
months. In my previous apartment that had pretty good insulation, we used
the heat for less than 10 days in a whole year. On the other hand, we used
the AC at least 180 days. If we had a decent radiant barrier on top of the
normal insulation, we would probably have used the AC only a little more
than the heat.
--
Ron Purvis
ronpurvis@charter.net
"John & / or Maryln" <schnahz@thisaintme.net> wrote in message
news:43f878ec$0$25086$1e6826b@news.chesco.com...
> Hi All,
> Would appreciate opinions on foil insulation. Here is where I
> started. http://www.radiantbarrier.com/physics_of_foil.htm
>
> Thanks, john
>
>
| |
| Ron Purvis 2006-02-20, 4:21 pm |
| That type of analysis is worthless. You can't tell us exactly how much the
problem is due to poor quality of materials, installation, or manufacturer's
defect. Also you have no way to show the way that the wind hit the shingles
differently due to site considerations. The only way to be able to draw a
reasonable conclusion is to test under controlled conditions.
--
Ron Purvis
ronpurvis@charter.net
"Harry Chickpea" <hchickpeaREMOVEME@hotmail.com> wrote in message
news:43fbe07c.1486441@news.east.earthlink.net...
> "Tony Wesley" <tonywesley@gmail.com> wrote:
>
>
> I would guess at about half, but the wind damage didn't happen
> according to age of the roof. One of the more damaged roofs was one
> that had been replaced after mine, but had dark shingles. Some cement
> tile roofs were fine, others were damaged, but most of the clay barrel
> tile roofs had at least some damage. I'm not really crowing about how
> well my roof held up, I fully expected it to do fine in the CAT 1
> storm that we had. I'm more interested to see how it holds up after
> another ten years.
| |
| Harry Chickpea 2006-02-20, 4:21 pm |
| Derek Broughton <news@pointerstop.ca> wrote:
>Harry Chickpea wrote:
>
>
>Refrigerators heat up while they're cooling the contents, too. Surely this
>just requires an intelligent design to ensure that heat flows in the right
>direction.
I agree, but easier said than done, especially on a passive basis.
The dried air would have to be routed through a evaporatively cooled
heat exchanger to get it close to ambient temperature. Then you have
slightly warm dry air being blown into the living quarters, which is a
marginal improvement at best. Add a swamp cooler into that stream of
air, and you get cool moist air, which might drop the air ten degrees,
fifteen if you are lucky, but that air will again be humid.
In humid climates, the nighttime humidity is already at the saturation
point, so evaporative cooling using ambient air doesn't do anything
towards cooling below ambient temperature. You can use the cooled
moist air to cool a second stream of dry air, again using a heat
exchanger. This might drop the temperature of the dry air another
five to ten degrees. You can then split the cooled dry air into two
streams, and use one stream to pass through yet another heat exchanger
that is cooled by evaporation using the second dry air stream to
supply the air, etc. The volume of cooled air is halved through each
pass, so two or three passes becomes a practical limit.
Eventually, you figure that to get cooling of a volume of air
comparable to a heat pump, you have to have a large system of ductwork
and heat exchangers, plus fans, and you have to start recycling cooled
air rather than continuously inputting fresh hot moist air.
Ultimately, there has to be at least as much energy input into such a
system as is input into a heat pumping system. Yeah, it can be done,
but the scale gets unwieldy and the costs are high. The system also
doesn't work on cloudy days, since there isn't enough heat to dry out
the LiCL to restart the cycle.
| |
| Harry Chickpea 2006-02-20, 5:21 pm |
| "Ron Purvis" <ronpurvis@charter.net> wrote:
>That type of analysis is worthless. You can't tell us exactly how much the
>problem is due to poor quality of materials, installation, or manufacturer's
>defect. Also you have no way to show the way that the wind hit the shingles
>differently due to site considerations. The only way to be able to draw a
>reasonable conclusion is to test under controlled conditions.
I wholeheartedly agree that it doesn't hold to the standards of
scientific testing. I never claimed that it met those standards when
asked for a cite. Quoting myself, "This is one where I go by my own
real world experience and extrapolate from that."
For me, not having to pay a $10,000 deductible for a new roof is not
"worthless." My wallet doesn't care if I didn't do a standardized
test, and it doesn't care if reporting a real-world experience is met
with derision on usenet. Y'all do what y'all want, I'm keeping my
shingle temps down.
If you want to waste time doing a "scientific" test, weigh and toss a
shingle tab and a bit of tar paper in an oven set at 200 degrees for a
month, and then weigh them again afterwards. The difference in weight
will be the evaporated volatiles as experienced on a normal roof.
Stick another tab and paper in the oven at about 350 for a month, and
you can figure out about what the total volatiles are. Finally stick
another shingle tab and paper in the oven for a month at 110 degrees
and see if ends up with less weight loss than the other two. I'm not
going to bother, cause I'm pretty sure I know the answer. Stick a
shingle on a roof and after a few years it'll cup, split, and fail.
Stick one in your basement and it'll remain good. There is a reason
for that, and it ain't because raccoons are wearing it out by tap
dancing on it by the light of the full moon. :-)
| |
| daestrom 2006-02-20, 5:21 pm |
|
<alecn@houseneeds.com> wrote in message
news:1140459536.397248.283580@z14g2000cwz.googlegroups.com...
> John,
>
> Like any tool foil insulation it needs to be used in the proper
> context. What are you trying to achieve?
>
> We use a product call Low-E with great success is many of our radiant
> projects. We use it as a thermal break between the slab and the ground.
> The aluminum is sandwiched between two sheets of polyethylene foam so
> you get a thermal break, vapor barrier, easy to install, and something
> that holds up to 93 PSI worth of punding at a job site.
>
> We also use it for radiant under floor applications to reflect the heat
> back up a joist bay.
>
> You can see more info here on how we use it for mostly heating
> applications:
> http://www.houseneeds.com/shop/misc...lationindex.asp
>
John, this is *exactly* the kind of 'double-talk' you want to look out for.
Stuff like, "Mass insulations (foam boards/extruded polystyrene) even though
they may have high R-values(depending on thickness) will eventually
stabilize at that constant ground temperature of 55 degrees or lower
depending on climate. Therefore the mass insulation provides a constant
drain on the radiant system and the slab. "
Frankly, if they understood heat transfer, they would know that the slab
will *always* reach an equilibrium temperature between the heat flowing into
it from above, and the heat flowing out of it to the ground below. Even
with their product. The best you can hope for is to raise that equilibrium
temperature to a comfortable level by reducing the heat flow to the ground
below. But they're trying to make it look like their product isn't subject
to the laws of physics and it somehow 'breaks' the heat transfer path
preventing heat loss from the slab to the ground underneath.
Aluminum sandwiched between two layers of foam can have some benefit by
minimizing the radiant transfer across foam cells on one side to those on
the other. But this same reduction in heat transfer can be achieved with
simply thicker foam board. But their product does look like it is easy to
install.
But what is the actual heat transfer coefficient for a layer of this product
versus a 1/2" or 1" of foam board? I suspect the *real* difference isn't in
the heat transfer performance, but in the ease of installation, toughness
and price. It would seem if their product were remarkably better, they
would say so with numbers from an independent laboratory, not some paragraph
of mumbo-jumbo about 'thermal breaks' and 'seeking the cold ground below
it'.
Foil insulation spanning under joists of a radiant floor system is the sort
of niche that radiant insulation works very well. It reduces the downward
radiant heat transfer to an unheated basement or crawl space. Because of
the orientation, there is already very little convective heat losses in such
a situation, and no conductive losses. So now that we're down to just
radiant losses anyway, this becomes the 'best bang for the buck'.
daestrom
| |
|
|
>
> Foil insulation spanning under joists of a radiant floor system is the
sort
> of niche that radiant insulation works very well. It reduces the downward
> radiant heat transfer to an unheated basement or crawl space. Because of
> the orientation, there is already very little convective heat losses in
such
> a situation, and no conductive losses. So now that we're down to just
> radiant losses anyway, this becomes the 'best bang for the buck'.
>
> daestrom
>
daestrom, I'm in the process of putting a new floor in my house, while I
have it up I was planing on putting in fibre-glass insulation (about R3 as
the joists are 4 inches), with foil insulation under the joists. This is
more for stopping summer heat gain. although another thought I had was just
to block the sub-floor ventilation on the really hot days.
any ideas or links you have would be great thanks
Stuart
p.s. melbourne australia, so no freezing temps
| |
| Ron Purvis 2006-02-20, 8:21 pm |
| Harry,
No is telling you that you have to do anything. You don't want to put a
radiant barrier under the roof: then don't. However the assumption that you
saved $10,000 by not doing so is is only a very wild guess. I believe that
you are vastly over estimating the amount of heat gain in the shingles.
According to studies that are reported by Oak Ridge National Laboratory, the
gain is only 2 F to 10F.
The Florida Solar Energy Center says 2F to 5F depending on color of the
shingle.There are warranty statements from Elk, GAF, Celotex, Owens Corning,
Certainteed, and Tamko that allow the use of TechShield as roof decking
without affecting their shingle warranties as long as the shingles are
installed according to their installation instructions. (See
http://www.lpcorp.com/lpstructuralp...ation/faqs.aspx)
I think that you looked at something you didn't understand and so you made
assumptions that are completely invalid. Kind of like the ancient Norse
heard thunder so Thor was out there in the heavens making the noise. If you
choose not to find out the actual facts, so be it. You are as free to
believe what you wish. Just like the member of the Flat Earth Society.
--
Ron Purvis
ronpurvis@charter.net
"Harry Chickpea" <hchickpeaREMOVEME@hotmail.com> wrote in message
news:4406230e.18530672@news.east.earthlink.net...
> "Ron Purvis" <ronpurvis@charter.net> wrote:
>
>
> I wholeheartedly agree that it doesn't hold to the standards of
> scientific testing. I never claimed that it met those standards when
> asked for a cite. Quoting myself, "This is one where I go by my own
> real world experience and extrapolate from that."
>
> For me, not having to pay a $10,000 deductible for a new roof is not
> "worthless." My wallet doesn't care if I didn't do a standardized
> test, and it doesn't care if reporting a real-world experience is met
> with derision on usenet. Y'all do what y'all want, I'm keeping my
> shingle temps down.
>
> If you want to waste time doing a "scientific" test, weigh and toss a
> shingle tab and a bit of tar paper in an oven set at 200 degrees for a
> month, and then weigh them again afterwards. The difference in weight
> will be the evaporated volatiles as experienced on a normal roof.
> Stick another tab and paper in the oven at about 350 for a month, and
> you can figure out about what the total volatiles are. Finally stick
> another shingle tab and paper in the oven for a month at 110 degrees
> and see if ends up with less weight loss than the other two. I'm not
> going to bother, cause I'm pretty sure I know the answer. Stick a
> shingle on a roof and after a few years it'll cup, split, and fail.
> Stick one in your basement and it'll remain good. There is a reason
> for that, and it ain't because raccoons are wearing it out by tap
> dancing on it by the light of the full moon. :-)
>
| |
| Derek Broughton 2006-02-20, 9:21 pm |
| Harry Chickpea wrote:
> Derek Broughton <news@pointerstop.ca> wrote:
>
>
> I agree, but easier said than done, especially on a passive basis.
Yeah, you're probably right. Theory is great - in theory :-)
--
derek
| |
| Harry Chickpea 2006-02-21, 12:21 am |
| "Ron Purvis" <ronpurvis@charter.net> wrote:
> we used the heat for less than 10 days in a whole year.
>On the other hand, we used
>the AC at least 180 days. If we had a decent radiant barrier on top of the
>normal insulation, we would probably have used the AC only a little more
>than the heat.
Don't you think that is stretching the truth a little, especially if
the place has "pretty good insulation?"
Someone just gave me a good quote:
"If you choose not to find out the actual facts, so be it. You are as
free to believe what you wish."
| |
| Ron Purvis 2006-02-21, 1:21 am |
| Harry,
Anyone who knows me, knows stretching the truth is not what I do.. I said
what I believe is the truth. Dropping the amount of heat that entered the
apartment from radiation by up to 50% would be very significant. For a fair
part of that period we only used the AC for one to two hours daily. All of
those days would not need the AC if a radiant barrier was in place. The vast
majority of the days, the AC was in use for less than 3 hours. Again, I
think that if a radiant barrier had been in place we could have made due
with fans and not used the AC at all on those days. We would have been able
to use fans to keep it bearable.
Yes, I do think that we could have made do only using the AC a little more
than the heat if we had a good radiant barrier on top of the normal
insulation that is already in place. Other areas will have different
results. The Greenville area gets hot in the afternoon but the mornings and
evenings gets cooled off from the mountain air to the north of us. If you
can keep the sun from radiating heat into the home, you can save an awful
lot on cooling the place. Other areas of the country, even others of SC,
will be different in the results they achieve. However, the ORNL report
says "The tests to date have shown that in attics with R-19 insulation,
radiant barriers can reduce summer ceiling heat gains by about 16 to 42
percent compared to an attic with the same insulation level and no radiant
barrier." That is nothing to sneeze at. Especially if the largest part of
the heat gain is from radiation.
As for your last comment, I can back up everything I have said. You can
check everything I say by doing research and find that I am correct. In none
of you posts that I have seen, has there been any rational basis for you
posts. So keep your quotes to yourself.
--
Ron Purvis
ronpurvis@charter.net
"Harry Chickpea" <hchickpeaREMOVEME@hotmail.com> wrote in message
news:440d89c3.44828207@news.east.earthlink.net...
> "Ron Purvis" <ronpurvis@charter.net> wrote:
>
> Don't you think that is stretching the truth a little, especially if
> the place has "pretty good insulation?"
>
> Someone just gave me a good quote:
> "If you choose not to find out the actual facts, so be it. You are as
> free to believe what you wish."
| |
|
| Daestrom
Thanks for the copy points we are always looking to improve our copy so
it is easier to understand. We don't claim to be Thermo dynamical
engineers we are folks that sell and install a lot of Radiant Heat
applications.
The insulation is a Polyethylene barrier with a 99.4% Polished Aluminum
/ PE foam laminate to both exterior surfaces. One of the main benefits
is workability. So you have all of the qualities of a two layer process
in one easy to apply roll, with sealing tape. An alternative install
would be plastic sheeting and Polystyrene foam board. One of the
problems with using this system for radiant is the damage that can
occur during installation.
As tubing loops are laid out, walking creates cracks in the foam and
perforations in the plastic moisture barrier. If the slab is an area
with some ground water, this can be a problem. Water touching the slab
creates further heat loss.
Many of our customers are first timers. Use a product that has a high
Puncture Resistance of 92.9 psi., with a contiguous layer, that
isolates the slab completely from moisture, while giving the added help
from the foil center. So why use a radiant specific product? Price,
time to install and piece of mind. Keep in mind most of our customers
just like us have a weekends and nights to work on projects.
As to independent ratings and test it is tested to ASTM C 518-98 at R
2.9. You can check out the manufactures site here for more detailed
info: http://www.lowe.com/Pictures/Web%20...ab%20Shield.pdf
Alec
| |
| daestrom 2006-02-21, 7:21 pm |
|
"Alec" <alecn@houseneeds.com> wrote in message
news:1140536435.272158.28270@o13g2000cwo.googlegroups.com...
> Daestrom
>
> Thanks for the copy points we are always looking to improve our copy so
> it is easier to understand. We don't claim to be Thermo dynamical
> engineers we are folks that sell and install a lot of Radiant Heat
> applications.
>
> The insulation is a Polyethylene barrier with a 99.4% Polished Aluminum
> / PE foam laminate to both exterior surfaces. One of the main benefits
> is workability. So you have all of the qualities of a two layer process
> in one easy to apply roll, with sealing tape. An alternative install
> would be plastic sheeting and Polystyrene foam board. One of the
> problems with using this system for radiant is the damage that can
> occur during installation.
>
> As tubing loops are laid out, walking creates cracks in the foam and
> perforations in the plastic moisture barrier. If the slab is an area
> with some ground water, this can be a problem. Water touching the slab
> creates further heat loss.
>
> Many of our customers are first timers. Use a product that has a high
> Puncture Resistance of 92.9 psi., with a contiguous layer, that
> isolates the slab completely from moisture, while giving the added help
> from the foil center. So why use a radiant specific product? Price,
> time to install and piece of mind. Keep in mind most of our customers
> just like us have a weekends and nights to work on projects.
>
Yes, I agree that your product can certainly be easier to install and
probably suffer less damage in the process. I said as much in my last post.
And as you point out, it combines two construction needs in one easily
installed product (both a layer of insulation and a vapor barrier).
But that isn't really so much a result of using a radiant barrier in the
middle of it, as it is the particular foam material and polyethylene barrier
and PE foam laminate, right?
> As to independent ratings and test it is tested to ASTM C 518-98 at R
> 2.9.
For the 1/2" thick product? Compared to a 1/2" layer of rigid foam at R
values between 2 and 3.3. While your stuff looks like a good and useful
product, the layer of "97% pure aluminum" doesn't seem to really add much in
the way of insulation value. Perhaps it adds to the overall toughness and
ease of installation (or vapor blocking), but as a 'radiant barrier' it
doesn't seem to do much for it.
> You can check out the manufactures site here for more detailed
> info: http://www.lowe.com/Pictures/Web%20...ab%20Shield.pdf
>
Thanks, but I can't seem to get that link to work. Lowe fishing boats?
daestrom
| |
| daestrom 2006-02-21, 7:21 pm |
|
"Ron Purvis" <ronpurvis@charter.net> wrote in message
news:1yoKf.31$Qq1.8@fe03.lga...
>A radiant barrier is primarily helpful in the deep south where you have
>almost no heating and a lot of cooling. I live in Greenville, SC and it is
>a tremendous help here. The typical household here will use AC daily at
>least April to October, whereas the heat will only be used sparely for a
>couple of months. In my previous apartment that had pretty good insulation,
>we used the heat for less than 10 days in a whole year. On the other hand,
>we used the AC at least 180 days. If we had a decent radiant barrier on top
>of the normal insulation, we would probably have used the AC only a little
>more than the heat.
>
One of the problems with radiant barriers is they lose their effectiveness
if they get dust/dirt on the radiating surface. (dust/dirt radiate IR about
as good as ordinary building materials) So to maintain it's effectiveness,
most manufacturers recommend installing on the upper side of the space to be
insulated.
This means it works good under floor joists to minimize radiant losses
downward from a floor into a crawl space. Or mounted on the rafters in an
attic so hot roofing doesn't radiate energy down onto the insulation on the
attic floor.
But rolling it over the top of attic insulation, it will get dirty and lose
it's effectiveness pretty soon.
daestrom
| |
| Ron Purvis 2006-02-21, 9:21 pm |
| Daestrom,
Sorry for the way I worded my post. I did not mean laying the radiant
barrier on top of the attic insulation. What I meant by saying "on top of",
was "in addition to". It is just the local manner of speech. I do understand
that you just can't lay the radiant barrier on top of the insulation that is
lying on the attic floor. It must be properly installed or it will lose its
effectiveness in a fairly short period of time. I would also like to point
out that most people tend to ignore placing the radiant barrier in the
walls. In an area like mine, this could be a big help.
--
Ron Purvis
ronpurvis@charter.net
"daestrom" <daestrom@NO_SPAM_HEREtwcny.rr.com> wrote in message
news:ZBMKf.23533$j53.20983@twister.nyroc.rr.com...
>
> "Ron Purvis" <ronpurvis@charter.net> wrote in message
> news:1yoKf.31$Qq1.8@fe03.lga...
>
> One of the problems with radiant barriers is they lose their effectiveness
> if they get dust/dirt on the radiating surface. (dust/dirt radiate IR
> about as good as ordinary building materials) So to maintain it's
> effectiveness, most manufacturers recommend installing on the upper side
> of the space to be insulated.
>
> This means it works good under floor joists to minimize radiant losses
> downward from a floor into a crawl space. Or mounted on the rafters in an
> attic so hot roofing doesn't radiate energy down onto the insulation on
> the attic floor.
>
> But rolling it over the top of attic insulation, it will get dirty and
> lose it's effectiveness pretty soon.
>
> daestrom
>
>
| |
|
| Yep for the 1/2 product.
Here is the link just to the site as the other was a PDF spec sheet:
http://www.low-e.com/
| |
| daestrom 2006-02-22, 6:21 pm |
|
"Alec" <alecn@houseneeds.com> wrote in message
news:1140616172.719715.89300@g14g2000cwa.googlegroups.com...
> Yep for the 1/2 product.
>
> Here is the link just to the site as the other was a PDF spec sheet:
> http://www.low-e.com/
>
Ah.... 'low-e'. In the other link, somehow the '-' got lost and 'lowe.com'
is for something entirely different. Now that I have the right URL, I'll go
read the pdf.
thanks,
daestrom
|
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