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1 Answer

We are retrofitting a slab on grade portion of our home that has an existing 4" thick concrete slab with a thinnish layer of insulation underneath. We are going to install radiant heating over top of this existing slab. There's an existing fireplace in the room and the hearth is 3 inches above the existing slab.

So to keep the new radiant overall thickness to roughly 2 1/2 inches to allow for 1/2 inch for wood flooring I was going to install 1/4 inch thick extruded poly (Owens Corning fanfold) then Hilti wire mesh, then 5/8 tubing, then gypcrete.

Asked By chris hoy | Aug 26 14
10 Answers

We are building a straw-bale house with steel bones in Sacramento, CA in spring 2015 and I'd love to get some insights from the community! We are pretty far along into the design process, but with nothing purchased as of yet I'd love to get some input before we put our money where our mouths are.

Our goal is to have a (mostly) passively heated and cooled home in (relativity) temperate Sacramento, CA. Passivhaus would be nice but it's an aspiration rather than a goal. Our lot has a number of trees for shade that we plan to utilize, especially in the western aspect.

Asked By Nick Campbell | Aug 26 14
2 Answers

I got a quote for windows from Intus and thought it the quote was high. But I do like the windows themselves.

A 24 x 48 fixed window was $385 with a simple grid pattern white - thats 48.13 sft
A 36 x 48 operable window was $745 white - thats $62.60 sqft faces west
and a 42 x 72 operable window white $1000.00 thats $47.62 faces west

I read somewhere on GBA blog that a typical Intus window was $30-35 sft fixed and $40-$45 operable, I have 34 windows and only 7 are operable and totals $28,000, is this reasonable or not???

Asked By Sam smith | Aug 26 14
12 Answers

I was speaking with my passive house consultant the other week, and she expressed concerns about boring critters and subsurface rigid insulation. She had such an experience with some insulation in her garden (It was put in one season and removed at a later time as she got back to completing the project.)
Now, I know all about the ate/termite protection used in these insulation products, but what about larger critters that would love to have a warm dry home?

Asked By Steve Young | Aug 16 14
32 Answers

Does anyone know if there are any companies that offer residential fuel cells on a lease program?

I met someone at RESNET this year who worked for a company that was offering such a program, but I have not been able to reach him since mid-March.

I'd like to utilize one to carry the electrical load on my future home.

Thanks for any help you can offer.

Asked By Mike Collignon | Jul 24 12
8 Answers

I would like to ask the math pros here on how to calculate heat loss from infiltration rates.

I have seen so many different formulas in the last weeks that my head is hurting.

So would like to have a "reliable" formula that could be used in my never-ending expanding excel spreadsheets !

Something with at least a little bit of proven precision, that could be used to effectively get additional heat loss using door blower results or planned target value.

Links or straight formula please :)

Asked By Jin Kazama | Aug 25 14
4 Answers

I would like to decide on putting in solar panels to reduce energy costs.

I have read about the next generation solar panels not being to far off.

Question: Would it be better to install current solar panels or wait for the new type that will be coming shortly?

Asked By John Alberti | Aug 26 14
1 Answer

I am in the process of trying to determine how much strapping spacing is needed on a ceiling to support 22" of blown-in cellulose above it. The strapping is 1x4 pine and I plan on spacing 16" OC whixh makes the space between supports of 12". The strapping is holding 6 mil poly up against the bottom chord of the truss. There will be some ballooning of poly downward in those squares between truss and strapping. 5/8" Sheetrock will be used up against strapping to finish. Thanks in advance.

Asked By Matthew Michaud | Aug 26 14
28 Answers

My house has high levels of CO2 / carbon dioxide, every room is between 1100 ppm to 1200 ppm according to an air quality test I had. There are only 2 grown occupants and it's a 1000 sq. ft. brick house. No pets or plants, gas stove / furnace / water heater.

The basement was the only area that had between 900-1,000 ppm of CO2. I've read ASHRAE likes to see under 1000 ppm of CO2. We do have headaches & drowsiness but aren't sure if it's strictly from CO2. For reference, our CO (carbon monoxide) numbers were all under 2 ppm.

Asked By Jeff Watson | Mar 9 14
6 Answers

Wondering if someone can identify a specific product for this application. The merits of the application might entice some to debate, but I am neither a code writer nor building inspector, just a guy caught between them.

I have a job with a woodstove in an art studio space. It does not have a direct connection from the firebox to an outside air duct, and it would be difficult and costly to accomplish that, because the stove is on a concrete slab, it is against a wall with a garage on the other side, and it's 12' from any exterior wall.

Asked By David Meiland | Aug 26 14
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