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4 Answers

Thoughts on PERSIST construction in Chattanooga, zone 4a

I'm designing my home using the PERSIST technique and would like input on insulation ratios that are suitable for my climate zone. I'm in Chattanooga, climate zone 4a, with 3587 heating degree days and 1544 cooling degree days.
Practically speaking, we have 3 months of trying to stay warm, and 8 months of desperately trying to stay cool.
My plan is a 1200 square foot, 2 story, flat-roofed house with a simple footprint, oriented for passive heating, windows placed accordingly.

In Green building techniques | Asked By Myles Freeman | Feb 25 14
6 Answers

Strapping for dense pack cellulose

Looking for recommendations on the correct strapping spacing (12" or 16") to help prevent bulging with a dense pack cellulose installation on walls. We will be using Insulweb over 8" cavities, 16" on center framing.

In GBA Pro help | Asked By jessie pratt | Feb 25 14
4 Answers

Where are commercially available VIG windows? Are they vaporware?

When I first read about vacuum-insulated glazing (VIG) several years ago, I got really excited; R-10+ windows!! I've been checking every couple of months since to see if they were commercially available and they STILL don't appear to be.

I've got my 100+ year old home almost up to passive house standards with air sealing/insulation. The foreclosed-upon house flippers that we bought our home from installed the cheapest builders grade dual pane windows they could. These are the weakest link in our home's energy efficency.

In Green products and materials | Asked By David D | Dec 12 13
2 Answers

Zip-R sheathing and spray foam?

I am looking to build my house in Birmingham, AL, Zone 3. I plan on using Zip-R 1 1/2" (possible 1" due to cost) and use 2x6 advance framing minus the single top plate. The exterior will have brick veneer.

My question is about using spray foam in conjunction with the Zip R polyiso. Is it chemically compatible? Thought on just filling up 24" cavities with open cell vs 2" CC and R15 batts?

I am a little worried about the CC not allowing drying to the inside, however, I'm not sure, since it will be bonding with the polyiso.

In Energy efficiency and durability | Asked By Paul Pankey III | Feb 24 14
23 Answers

With $15,000 would you buy PV or improve your envelope?

Last night I went to an informational meeting sponsored by Solarize CT. This organization negotiates with solar companies to reduce installation costs for PV panels. They keep lowering the price in accord with how many people sign a contract. Currently they're offering installed panels at $3.30 a watt. A 9 or 10kw array would likely meet all our electrical power needs. Also at the meeting were lenders who will finance the net cost (less 5% down) for 15 years at 6.5%.

In General questions | Asked By Patrick McCombe | Jan 24 14
1 Answer

Ducts inside?

Has anyone done or seen soffit or chase retrofit inside home envelope from flex duct in the attic? In other words, move ducts indoors.

I want to get rid of my 20-year-old falling-apart money-hungry flex ducts that are in the attic. Read that it is more efficient inside. My Jim Walter home is more like a double wide mobile home about 1200 sq ft single story ranch, raised foundation crawl space, no basement, central air with air handler inside.

In Energy efficiency and durability | Asked By Valerie Morgan | Feb 25 14
3 Answers

Why are there so many spam links in the Q&A?

I see lots of spam.

In General questions | Asked By Tom Perkins - Midcoast Maine CZ 6A | Feb 24 14
2 Answers

How to best insulate a new truss roof?

I am going to build a new home in northern Idaho, zone 5. It will be a ranch house with walk out basement. Most of the house will have scissor trusses, 8/12 pitch upper and 4/12 pitch lower. With the exception of two shed dormers that will be stick framed. I originally thought of closed cell spray foaming the entire underside of the roof deck for an unvented attic space.
There will be a few areas which will most likely have 9' flat ceilings such as baths & closets.
Would this be the optimal approach as opposed to using batts and blown in on top of that and venting the attic?

In Energy efficiency and durability | Asked By James Mills | Feb 24 14
9 Answers

What is the best cold climate basement strategy?

We are building a new home in the Black Hills of South Dakota, about 20 miles south of Rapid City. The floor plan is nearly finished. The home is a ranch style with a partially finished walk out basement. There is a small loft area for an office above the mudroom/ laundry/ pantry. There will be about 4,150 sq. ft. finished. The home will face due south.

In PassivHaus | Asked By Tom Hanke | Feb 15 14
7 Answers

Is hydronic heat worth installing in an old house?

I have a client who is convinced that replacing their 80% gas-forced-air furnace with a hydronic system will improve their comfort. The plan is to install a gas-fired boiler to serve both the heat and domestic hot water needs, and staple PEX below the floor in the joist bays. We've discussed the options of a more efficient furnace, or a duct-less mini-split, but byronic is still their preference.

In Mechanicals | Asked By Lydia Marshall | Feb 19 14
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