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8 Answers

Mini-split, air circulation and noise transmission

We are considering using a mini-split system on our new tight home (double wall cellulose on a insulated slab) in Upstate NY (Zone 5a). We are both consultants with full time home offices.

One option is a hidden short ducted system on the first floor (1,500 sf) to duct air to the main living area and the master bedroom area and a regular mini-split unit for the upstairs (800 sf) where we will have our two offices, a bath, storage and a guest room. Our mechanical room is on the second floor. I don't want a visible unit on the first floor.

In Mechanicals | Asked By Elizabeth Kormos | May 10 12
8 Answers

Where is the water coming from?

I am working on a house about 30 miles north of NYC. It has had a paint peeling problem for 15-20 years, ever since the house was renovated. It has many large thermopane windows, all with copper pans below. It has a narrow continuios vent at the fascia, no soffit, and a 41/2" pitched roof over the windows that extends to the ridge. the rest of the roof is a 6 1/2" pitch with the same venting detail. there is a continuios ridge vent. It is sided with 3/4" x 10" redwood clapboard siding that was back primed with a 2 1/2" overlap over Tyvek and Barricade wrap around window openings .

In General questions | Asked By James DeSalvo | May 9 12
1 Answer

Polyiso designed for roofing OK in crawlspace?

I want to seal and insulate my crawlspace walls and rim joist area in an affordable manner, which for me is about as close to zero as possible. So I found a guy who has a bunch of used 4'x8'x1.5", with black paper facing on both sides, for $5 per sheet. In looks like its pretty good shape from the photos I've seen and the price seems like 1/5 the retail price.

My question is: what is the purpose of the black paper facing and is it OK to use in spaces other than roof applications?

In Green products and materials | Asked By David Martin | May 10 12
4 Answers

Lighting strategies

i could not find this on any other forum and hopefully my post is relevant

Is there a way to get natural sunlight into a dark room? I have a 1st floor living room in an attached house (attached from both sides) and this room runs north south and has some windows on the south-facing side. Could I use some technique to light up the whole room using these windows? I see a technique listed here but it needs direct access to the roof


In Green building techniques | Asked By sam dhak | May 9 12
6 Answers

What is the the thermal mass heat storage capacity of 1/2 inch of sheet rock?

I understand that the BTUs per degree of F per square foot of 4" thick brick pavers is 9, of builder's brick is 6.5 and of hard wood is 1.7 per (Johnston and Gibson, Towards a Zero Energy Home). What are the BTUs per degree of F per square foot of 4" thick sheet rock?
I am building a 1550 sf one-story zero energy home in Bend Oregon. It will have .6 ACH@50p and will have 50 R walls and floor and 60R ceiling. The windows will have a .2 u-value and a SHGC of .6. The south facing living area is approximately 600 sf.

In PassivHaus | Asked By Joseph Emerson | May 8 12
3 Answers

Duct Insulation R Value in a Attic with a spray foam roof deck.

Definition of Conditioned Space - Spray foamed attic/roof deck
I am consulting on a new construction house for efficiency. We are spray foaming the entire house including the bottom of the roof deck. The HVAC installer finished his rough in. His duct work is wrapped with R6 insulation in the attic because he understood it was a "conditioned space"
The building inspector failed his rough in because he said the area was not directly conditioned with its own supply and return so the duct need to be R8.

What is your opinion and suggestions?

In Building Code Questions | Asked By Paul Pankey III | May 9 12
4 Answers

Wood gasification boilers

I have a friend in town who is thinking of installing a wood gasification boiler to run his hydronic heating system and domestic hot water. As I haven't come across many of these before I am hoping some of you guys can give some advice that I can pass on. I believe he is considering one of the following units; Econoburn, Empyre Elite or a Woodgun.
Many thanks

In General questions | Asked By Ray Smith | Apr 3 12
7 Answers

Zone 5 - Vapor Retarder on ceiling of indoor swimming pool

I an an insulator and a little confused on the subject of vapor retarders for ceilings. Normally we do not put a vapor retarder on the ceiling for Zone 5. But we are doing a job for someone that is enclosing their swimming pool and I am concerned that with that much humidity it might be necessary. They are installing an air-exchange unit of some kind but I do not have any details on that at this time. If this question has already been answered, can you please direct me to that thread?

Thank you

In GBA Pro help | Asked By Lisa Goodman | Feb 6 12
6 Answers

Experience with "Drain Plane"?

Has anyone had experience with Drain Plane, a recycled-plastic, vertically-applied furring strip by G.B. Williams that is sold for use in rain screen assemblies? (http://www.drain-plane.com) I wonder if it could be used over foam sheathing in place of 1x4s. Any comments welcome.

In Green products and materials | Asked By Gordon Taylor | May 9 12
32 Answers

A blog for "air-tight" sheathing nuts

For those who are interested, here is a link to a blog that I have started about my building project.

Please note that the blog has only just gotten started and has a ways to go before it catches up to the actual project.

It generally covers the technical aspects of the build but I have also included (and will be adding) construction details for a "truss wall" with "air-tight" sheathing approach I have been working on.

In Green building techniques | Asked By Lucas Durand - 7A | Dec 7 11
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