Hi -- I'm looking at SIPs walls and roof panels made by Eco Panels, and am wondering about off-gassing issues related to these products. Eco Panels claims there is no off-gassing with their products, which I would like to believe, but I'm skeptical.
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You have to attach the foam to the walls with some kind of glue, which would contain VOCs. They claim their foam contains no VOCs, but don't say anything about the glue.
I'm particularly worried about off-gassing with SIPs because the house will be so tight, trapping potentially harmful VOCs in the house and negatively affecting indoor air quality.
Does anyone have any insight into this issue? Are there any scientific studies that address this problem?
The purpose of building an air tight house is not to reduce ventilation but to ensure the ventilation is controlled. You still need the right number of air changes per hour or you get high humidity etc.
Which is a good point, any air-tight house needs forced ventilation to be both comfortable and safe. Heat/air exchangers are the normal way of doing this, however one must factor in their initial cost, and operating costs when planning construction.
"Adhesives shall be in conformance with ICC ES AC05 ? Acceptance Criteria for Sandwich Panel Adhesives"
.. so the ICC and their acceptance standards (AC05) might be the place to look.
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A number of years/decades ago, I worked for a short while installing insulation. Much of it was shooting foam into walls but I am guessing this is not the same as the foam used now so those gory stories are best left untold.
You might revisit the idea of 'tight' as Cwatters suggests. It is more about being able to control the ventilation than trapping air.
We just finished construction last Aug. on a Energy Star 50+ passive solar home constructed from ICF's (basement - Nudura) and SIPS (1st floor & dormers - Insulspan brand). And yes, passive solar does work in Northeast Ohio!
The house is extremely airtight - received the highest blower test score the certified Energy Star rater had ever seen and he has done over 100 houses.
Our HVAC system includes an Aprilaire 8100 ERV ( energy recovery ventilator) that runs continuously, using the equivalent of a 120 watt light bulb to provide full house air changes every 3 hours. You have to have either an ERV or HRV if you build an airtight house.
We have great indoor air quality - the house just smells fresh all the time. The ERV draws its outgoing air from the laundry room and two main floor bathrooms, continuously expelling moisture and odors in addition to stale air. We still have exhaust fans in the bathrooms and over the cooktop for direct venting of moisture and odors from those areas, and the baths that have showers have timers on their fans.
I would suspect that the construction materials, adhesives(subfloors, drywall, etc.), and finishes used thoughout the project have a higher VOC content than any glue in the SIPs themselves.
Does this mean you might actually buy that house or are you still diddling around?
The actual answer to your question is that:
1) You have to specify what the insulation is---isocyanurate, styrofoam---and how the panels are constructed. What is the inside wall made of?---it may outgass formaldehyde more than any insulation.
2) There should be a vapor barrier on the inside wall in any case.
3) The people who are talking about air exchange are correct although you can get crazy about that as well.
Seriously, opening a window is very low tech and very cheap.
It's hard to find a builder that will build me a SIPs teepee (with passive solar, no less), let alone a bank that will finance it.
Polyurethane foam. They claim it does not offgass:
"Our foam does not off-gas (see FAQs for more information on this) and it does not contain CFC=92s, HCFC=92s or formaldehydes that can be harmful to people and the environment. With respect to safety polyurethane foam is a thermoset material =96 it does not melt and under most conditions does not promote flame. Please see the =93SIP Burn Test=94 linked from the homepage for a demonstration of how our foam (and our competitors=92) reacts to a blow torch. The strength of our foam, when coupled with even basic siding materials like OSB, has exceeded vertical compressive strength tests of over 50,000 lbs for a single
4=92x8=92, 4.5=94 wide panel!"
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I'm extremely sensitive to chemicals, that's why I'm asking. I'm probably being overly cautious, but I don't want my home to make me sick (been there).
These panels look like a great product to me. But they would destroy the construction industry and put lots of people out of work, so it will be a slow process for them to gain traction.
I didn't see if they make higher R-values; I would like to see these used for roofing.
As for chemical sensitivity---again, the inside wall looks to be made of OSB, which should be sealed off from the interior anyway. There's no way to 'shrug' off the need for a (good) vapor barrier.
Yes, OSB layers -- forgot to mention that. Everyone I've spoken to in the green building biz raves about their products.
The wall panels are R-26, and the roof panels are R-40, which I think is pretty darn good. The home that I'm modeling my home after (which uses these products) recently broke the blower door test record in my state.
Hey, what do you think about a wood stove? With the concrete slab/ passive solar + wood stove, I'm thinking I may never have to use the heating system. I'm considering going with a geothermal heat pump, if I can afford it, but wonder if that might even be overkill. Although given the 2-month span of consistently below freezing temperatures we've had here, maybe not.(the climate here is generally pretty temperate -- rarely do we get extreme hot and cold temps).
Since our last go-round on this topic, I've done a bit more reading on pellet stoves, as well as a lot of chain-sawing and maul-splitting. Motivated by the latter, I purchased a bag of pellets to experiment with in my wood stove. What was fascinating was realizing that the bag had been shipped from Georgia or some such god-forsaken place, which makes no sense when we have lots of overgrown forest here in the Northeast.
But anyway, everything I've read inclines me towards the pellet stove, much as I like looking at the flames dancing on the logs and musing on the metaphysics of randomness. I assume you don't have several years worth of dead-standing firewood on your land like I do thanks to that non-existent global warming causing non-existent pests and disease to arrive from your part of the planet.
Thanks for info on the pellet stove . . . definitely something to look into . . . especially since I'll definitely be living in town on a very small plot without several years of dead wood supply (sorry about that).
And thanks for the info on the SIPs awhile back -- see, alt.philosophy can change the world. ;-)
Automatic pellet boilers are also available (at least in the UK) but they can be fussy to set up as they don't switch on/off instantly. It's pretty essential they are used with a thermal store to reduce cycling.
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