I was told that color would not make much difference in the heating effect of a black plastic flower pot because the sides of the pot are nearly vertical. My understanding is that holding other things constant, a lighter color would be more effective in reducing heat buildup than a darker color. The question sounds a bit wonky, I know, it came up in a gardening group run by university extension agents, normally pretty well-educated people, so I am reluctant to butt heads without a bit more information.
We have a vinyl garage door that faces due East and the garage really heats up in the warmer months because of this orientation. The R-Value of door is maybe R-3 +/- according to the manufacturer. I considered adding more insulation on the interior of the door, but that does nothing to reduce the exterior heat input. Would a reflective vinyl approved paint on the exterior of the door help reduce heat absorption in your opinion/experience? Thank you for your time and thoughts on this challenge.
I plan to build a climate-controlled garage in North Texas, near the Red river. I want to achieve R-30 in the walls and R-40 in the ceiling. The HVAC air handler and all ducts will be within the climate-controlled space. Exterior walls and roof will be finished with steel sheet panels.
1. Will it be effective to sheath the building with foil-faced OSB (foil on the outside), then place 2 x 4 stringers flat on the outside, followed by the steel sheet on top of the stringers; achieving a 1-1/2-inch air space between siding and sheathing? Is there benefit to increasing the air gap from 1-1/2 to 3 inches?
2. Is there than any negative affect from applying at least 5 inches of open cell spray foam to the inside?
3. Radiant barrier house wrap; what and where? To my knowledge, Tyvek is not a radiant barrier. The foil faced OSB is a radiant barrier, do you recommend redundant radiant barriers? If so, should there be a separate air gap for each barrier? My understanding is that placing anything in the air gap between the inside roof surface and the reflective radiant barrier is counterproductive.
I am a writer and am researching radiant barriers and building codes–specifically, which codes have incorporated radiant barriers as part of a prescriptive compliance path. I am aware of California’s Title 24, but am having trouble efficiently researching what other states or municipalities have similar language.
Someone mentioned Honolulu and Florida. I did find something about a “radiant barrier credit” in the Honolulu code, but am afraid I don’t understand what that means. I also found something from Florida’s 2007 code, but don’t know if that is still in effect.
Can you offer some guidance or point me to someone who can?
Can you explain the following statement in California’s Title 24? “The Title 24 prescriptive compliance approach requires a radiant barrier in climate zones with significant cooling loads (zones 2-15). The performance approach does not require a radiant barrier in any climate zone.”
I am writing to inquire about a conflict that has arisen in the re-roofing project of my home. A contractor has replaced radiant barrier decking in some areas with regular decking. We both are hesitant to remove the shingles to replace the decking with the correct product, but are unsure if there is an appropriate DOE/ASTM approved solution? Paint has been brought up, but that after reading the literature on your website I see that is not an effective solution.
I am planning on installing a radiant barrier in my attic and garage door. I read all over that radiant barriers and reflective insulation “must always be installed in the presence of an air space.” However, I have a few questions regarding that air space:
1. How big does the air space have to be?
2. Do you need air space on both sides or only one side (if only one side, which side is best)?
3. For the garage door, can I install insulation first (directly against the aluminum garage) and then attach the radiant barrier to the insulation? Again, I think this relates back to airspace, does the inside of the garage act as airspace or does the insulation?
I had a shed delivered to use as a hobby shop and plan on climate controlling it, so I was going to install batt insulation. I told the shed guys this and they talked me into getting the silver treatment, which is the radiant barrier OSB roof and wall sheathing. But when I went in the shed, printed on the silver side it says “for open wall use only.” Is there a way to add batt insulation with this?
I want to put a radiant barrier in my home’s attic. I plan to staple it to the underside of the attic rafters. Is that a good way to proceed? Also, I have seen materials with bubble insulation between foil faces and I have seen radiant material that is perforated with small holes, apparently for ventilation. Do either of these materials provide a specific additional benefit or is a solid foil material best or equally good?
Hi I’m in Corpus Christi, Texas. Is it okay to fasten non-perforated radiant barrier to the bottom of the rafters inside an attic? The problem is I ran short on my initial order of perforated radiant barrier and they sent non perforated radiant barrier instead. I have completed approximately 2/3 of the project and I have 1/3 left to do. Any input is appreciated.
Hello, I am speaking with two suppliers of two different radiant barriers. I am learning from them that it meets the CA acceptable cool roof alternative for compliance with both the prescriptive and performance methods for energy compliance as described in ES 150.2(b)1H. Energy Standards 150.2(b)H1 (prescriptive)and Table 150.2-B (performance).
My concern is they tell me I can install this product on a roof deck without a 3/4 or 1″ air gap between the deck, vapor barrier and roofing material, meaning direct contact between deck and roofing materials. I have learned in the past that radiant barriers need an air gap of at least 3/4″ of an inch to perform.
I am estimating on three different residential buildings to show the local building departments that these products can work to allow an alternative other than the more costly alternatives here in zones 11 & 12 CA.
Can you possibly supply me with a correct approach or any info possible to do this approval process?
I am looking to retrofit a home built in 1967 in Tampa, Florida. The current blown-in attic insulation is original and about 3 inches. Would a reflective insulation alone attached to the bottom of the top cord of the roof truss be a good option?
I am in the process of finishing my basement, my plan up until a few weeks ago was to lay 1″ rigid Styrofoam directly to the concrete floor covered by 3/4″ tongue and groove plywood subfloor. Visiting a friend while he was renovating a home for his kids, he mentioned that he was using reflective insulation in many areas of his project. As I started to research this product I was surprised by the number of companies and number of products that are available.
I have emailed 4 companies and actually talked on the phone with one of them. They have all convinced me to change my original design by replacing the rigid Styrofoam with a layer of reflective material directly to the concrete, installing 3/4″ furring strips then the subfloor. Although I live in upstate NY, I am not worried about an R-Value since my basement walls are spray foamed, but I do want a vapor barrier and hopefully will block any radon I have in the ground. How do I pick the best product from all this info overload? One company suggested a reflective material, the others have suggested bubble material, which they are suggesting the double bubble over single bubble. I asked one company why I need double bubble over single since one surface will be in direct contact with the concrete floor and he said it wasn’t that much more in price and it was easier to work with?
I would like to use one of these products due to easier installation and cheaper in the long run.
Please help me make sense of all the info I have gotten so far, and dispel some of the myths and marketing I am receiving from these companies!
I stumbled upon your site after going to the government energy site. I have a large sliding glass door in my condo that I need to block somehow in the summer so that the heat doesn’t come through, the condo gets unbearable. Should I get the reflective aluminum foil and tape it up on the windows? Hope you can send some advice.
Radiant barriers are an integral part of Hawaii’s energy code. The question came up about radiant barriers discoloring “like old silverware” over time, and of course, dust collection is an issue. Does the association measure performance drop–perhaps the same way that the CRRC measures aged reflectance over 3 years?
I am considering using a product called Low-E Therma-Sheet under a composite shingle roof to be installed in a few weeks. It is installed directly under the shingles with no air space.
I’m very concerned about the claims made about this product and wonder if your organization has any reports or reservations about this product — especially used in the manner I just described.
We had our roof redone during the summer. Low-E Thermal was installed at the suggestion of the contractor. We have a flat roof with no attic space whatsoever. The Low-E Thermal sheets were installed directly above the stripped roof, no air space above or below. Afterwards, the heat was worse than ever, even with the AC on, temperatures still rose to 85-90+ degrees. The roofer stated no air space was needed and that he did everything properly. What is your take? Was this correct? Any suggestions?
I’m installing a radiant barrier to the walls in an old house that never even had insulation. I’m using Kraft paper back rolls of fiberglass insulation between the 2×4’s. Where exactly should the radiant barrier be installed? Against the outside vapor barrier before installing the insulation, or on the “sheet-rock” side of the insulation?
I’m in the planning stages of replacing the cedar shake roof on my 1982 house located in Carbondale, CO (81623). The house has cathedral ceilings under the roof in all areas. As far as I can tell at this juncture the shakes are stapled/nailed onto plywood sheeting. Is there a manner that I can install a two-way radiant barrier during the re-roof process? We own a sizable portion of a community solar farm and have solar hot water panels on the house, so our energy bills are pretty low for a 4000SF, all electric house.
Also, I remember just enough about radiant energy to be dangerous from past physics classes, but I don’t understand why an air gap is necessary? Seems to me that a radiant barrier is a radiant barrier no matter where it is in the construction column? I’m sure you are correct on the air gap issue, I just don’t understand it, be that as it may, if I lay a radiant barrier on the plywood sheeting would corrugated steel on top of that provide enough air gap to be effective? My desire is to keep our radiant heat in during the cold months and the sun radiation out during the summer. Any means to that end that don’t require major reconstruction?
Is there a difference in heat gain in the house if you place the radiant barrier on the attic floor or roof section? On top of the studs, with a vapor space.
We are planning to use a radiant barrier in a new construction. It mentions in your (RIMA) manual for installation to use furring strips to separate the outer skin from the internal structural wall. I am guessing that this means: sheet rock, fiberglass or some type of insulation, the radiant barrier, furring strips followed by the exterior siding. The main question is, do the furring strips act as a thermal break or is there a product that should be used on the studs to avoid heat transfer through the wooden studs?