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4 Answers

Does anyone have experience with the Dow Powerhouse Solar Shingle?

Can the Dow Powerhouse Solar Shingle be safely installed on an unvented cathedral ceiling/roof which is insulated below the deck with impermeable closed cell insulation. will this Dow system trap moisture and condensation below it? What about the Certainteed Solar system which is installed directly on the roofing deck? For solar PV systems with modules raised off the roofing deck, what is the long term effect of shading, moisture and fungus on these shingles? Do these shingles below the raised solar PV module have to be replaced before the life expectancy of the solar PV system?

In Green products and materials | Asked By JOSEPH POLAND | May 19 13
4 Answers

Does earth coupling work?

I've purchased a city lot in Tucson, AZ and plan to build a tight, well insulated home on a concrete slab-on-grade within the next few years. It's a hot, dry climate with 1578 HDD, 3017 CDD, so obviously keeping the house cool is the big concern.

In Energy efficiency and durability | Asked By Michael McNulty | May 20 13
19 Answers

Experiences with grey-water and composting toilets?

Grey-water toilets: The Aqus toilet system (http://www.watersavertech.com/AQUS-Diagram.html)seems like the most popular (only?) grey-water toilet available. I really don't like the fact that it installs with a purification system and electric pump. Does anyone know of a model that does not have these features?

In Green products and materials | Asked By Lucas Durand | Oct 20 10
11 Answers

Smart vapor retarder (ie: MemBrain) installation details

I'm currently in the final estimation phase of my upcoming new build and we're coming in a little tight - so every little bit needs to be justified.

In General questions | Asked By Mike Goulet | May 15 13
2 Answers

Basement slab moisture barrier

I am finishing our 800 sq.ft. basement in Portland, OR (zone 4c). I am planning to lay a combination of carpet and linoleum and want to reduce the chances of mold from moisture that might seep up through the concrete slab, which varies in thickness from 2" - 4" in some spots. I have noticed a couple 6" diameter spots on the slab that seem moist during the rainy season, but no pooling of water.

In General questions | Asked By Matty McDermott | May 16 13
8 Answers

How green is my cloud?

I can't verify, but I read sometime recently that there's less embodied energy in buying a CD than in storing it on-line. Which got me to thinking about these monster servers that must be sprouting like mushrooms. I have a vision of us all living in lovely net zero homes, served by our own individual off-site servers consuming a Fukushima's worth of juice.

No real question. Just wanted to share my cheerful thought before the weekend.

In Energy efficiency and durability | Asked By Dan Kolbert | May 17 13
3 Answers

Quickly listing neighborhood amenities by LEED category

I am working on several LEED for Homes Midrise projects which are pursuing points under LL5 Community Resources. LEED outlines several categories of resources, like:

Arts and entertainment center, Bank, Community or civic center, Convenience store, Daycare center, Fire station, etc.

In Project management | Asked By Kris Knutson | May 17 13
5 Answers

Say you want a door but you also want to use it for solar gain. Is there a type of door style/material/size thats best?

I can't seem to get values for doors from manufacturers or when I do, the SHGC drops precipitously once you put the glazing in the door, e.g., Sungate 500 SHGC drops from .6 to less than .4 when put in a swinging fiberglass patio door. Of course glass size is limited to about 2 ft width, although the length is long. How I get what I need in SHGC in a south facing door. Do I change door style, size of door/glass, material, glazing brand, ? etc. Thanks

In Green products and materials | Asked By Lisa Young | May 16 13
3 Answers

Some help with estimation of wall assembly cost?

We are in the process of designing a passive house and are working with PH certified architect/consultant. But for now, builder's knowledge would be needed: a back of the envelope calculation for the cost /sf of this kind of wall assembly: fiber cement board w/ rain screen, fiber board, dense packed cellulose, OSB, dense packed cellulose, drywall. The wood framing will most likely be w/Larson trusses. The R-value we are trying to achieve is around 40. The house is a duplex with gross sf area of ~4500. Would be good to know the material & labor separately. Why do I need it?

In PassivHaus | Asked By Lucyna de Barbaro | May 16 13
2 Answers

Sealing a dry sump

My basement is fairly dry and well above the local water table
and hasn't had any water ingress over any of the major storm
events we've had, and has never had a sump pump. So I don't
really care about storm water; what worries me is the potential
for internal plumbing leaks as there's no way for the basement
to drain until it basically fills all the way up. So I'm
thinking of putting in a sump pump but into a small well that
*doesn't* connect to whatever gravel/earth/whatever is underneath
the slab -- it would be connected to the slab and sealed in and

In Mechanicals | Asked By Hobbit _ | May 16 13
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