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12 Answers

Is make-up air req'd for a Conditoned basement heat pump water heater vented to the outside?


I have a tight house (2.0ach50p) and want to install a heat pump water heater in the heated basement. I have no back draft appliances and the house is all electric with a fully ducted HRV system. I occasionally run the range top fan on low and a bath fan for 15 minutes or less (timer switch).

In Energy efficiency and durability | Asked By Frank O | Jan 10 12
3 Answers

Re-roof Question

This Zone 5, coastal roof is leaking and going to be replaced via a low-interest, deferred HUD loan. (See photos). I had dreams of a Deep Energy Retrofit, but even with generous incentives from the electric utility, the expense is too great for the loan recipient, and a VERY incremental approach is required.

In Energy efficiency and durability | Asked By John Rockwell | Jan 11 12
2 Answers

Seal or Vent Bottom of Balloon-Framed Wall?

I am replacing the water table and belly band on my 1903 house that had the foundation replaced.

The wall constructions is studs, turned either short or long side out, and then board and baton style sheathing, and then lap siding. The board and baton form a sort of drainage plane behind the siding. However, there's no building paper vapor or air barrier over the sheathing, and the boards seem like there are plenty of air leaks between them. The walls have cellulose insulation, and the siding is covered with asbestos cement shingles, which I hope to remove some day.

The dilemma is this:

In Energy efficiency and durability | Asked By Adam Liberman | Jan 11 12
5 Answers

Can anyone help with info (esp. technical documentation) about whether vented (soffit-ridge) or unvented roof assemblies are more resistant to high wind load damage?

A customer of mine is being told by his builder that he can't switch to roof deck spray foam and an unvented attic because that will change (reduce) the resistance to wind loads compared to the as-designed house with soffit and ridge vents. We are in a 130 mph wind zone.

In Energy efficiency and durability | Asked By Kevin Veach | Jan 10 12
5 Answers

Venting REMOTE insulated walls

I've been looking for a video article I saw in the last (2) months that covered the subject of providing a vent path at both the top and bottom of a wall insulated with rigid insulation at the exterior. The general concept was to place a thin strip of fiber-mesh type material between the 1x4 strapping bays at both the top and bottom. I remember the top end detail but the lower end detail is what I can't remeber accurately.

In GBA Pro help | Asked By Harry Seidel | Jan 11 12
15 Answers


I was nosing around on wikipedia and I came across the statement below regarding radiant barriers in wall assemblies.

I'm skeptical...
Can anybody verify that "wrapping a house with radiant barrier" can produce such results?

In Energy efficiency and durability | Asked By Lucas Durand - 7A | Jan 10 12
1 Answer

Icynene Spray Foam on Underneath Side of Roof Deck - Zone 5

After reading for months, getting 4 quotes from spray foam contractors in my area, and undergoing an energy audit, I'm in the process of finalizing plans for open cell half-pound Icynene application to the bottom side of the roof deck in the attic. This is a retrofit job. Within the attic is a furnace in a closed room vented directly to the outside. I have a few questions after I received the proposal today from the contractor

In Energy efficiency and durability | Asked By Kevin Hilton | Jan 11 12
4 Answers

Roof valley

I have a client with a roof valley that has ice damming problems ever year due to poor design and snow drifts off higher roofs. The valley end into a wall section . Other than installing de-icing cables does anyone have a suggestions

In General questions | Asked By Christopher Lorden | Jan 10 12
9 Answers

Earth tubes

Looking for the expert opinions regarding the use of "earth tubes" to temper incoming ventilation air. I understand that in some climates, that moisture must be carefully managed to reduce the risk of mold etc. The idea is appealing for those of us in climates with hot summers and cold winters.

In General questions | Asked By Garth Sproule | Nov 14 09
1 Answer

How to install siding and windows with rigid board insulation?

I have read through your articles and watched the videos on using polyiso for exterior sheathing and insulation. After spending quite a bit of time researching this issue, I would like to know your comments on the following.

I live in the Seattle area and have spoken to a company in Portland with a similar weather environment about the best way to accomplish the above. They recommended using polyiso 1 1/2" over my existing 1/2" CDX sheathing on the exterior (I am doing a remodel with new siding) by Hunter (no foil or material on it) followed by a housewrap for a water barrier.

In Green building techniques | Asked By Steve dorsey | Jan 10 12
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