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4 Answers

Will furring strips be needed over sheathing if using steel roofing?

I'm Zone 5 - upstate NY, planning to build 1050 s.f. ranch home, using r-20 superior wall basement, r-33 double wall cellulose.
If i build roof using 2x10, and gusset 2x4 underneath, filling with cellulose, and if i use 1" foam board to baffle/vent roof 1-1/2" beneath sheathing, i could obtain over r-43. here are my thoughts/questions

In Green building techniques | Asked By steven bumpus | May 21 12
2 Answers

Help deciding which Mini-Split HVAC to buy

I'm following advice from a previous question I posted here and planning to install a mini-split in my garage apartment. Various sources and calculations indicate an 18,000btu unit is optimal. I'm thinking of purchasing one online, doing some of the less technical work, and having my AC technician do the final hook ups, etc. I have a few questions inhibiting progress.

In GBA Pro help | Asked By Dorothy Prowell | May 20 12
2 Answers

An article on Chris Corson's Passivhaus in Maine

Here's a link to the new JLC article on Chris Corson's Passivhaus project in Maine:
An Affordable Passive House.

Nice work, Chris.

If you are interested in more information on Chris's project, you might want to read the GBA story about his house: Striving for Passivhaus Affordability.

In PassivHaus | Asked By Martin Holladay | May 17 12
2 Answers

Retrofit Vapor Retarder/Barrier in Ceiling Plane

I finally crawled up into my attic of the house I purchased four months ago. I knew that I needed to add significant insulation (currently has about 6"-8” of loose cellulose) as I want to get to R60. In advance of adding the additional insulation I am air sealing the attic. I was digging around in the insulation to find the various wiring penetrations, to foam them closed, and I was immediately struck that I didn’t find poly (or any other vapor inhibitor) on top of the ceiling drywall, as is the typical scenario in homes in my area.

In General questions | Asked By Pete Marthaler - Zone 7 | May 18 12
9 Answers

Combined HRV and mini-split ?

Are there commercially available units which combine heat-recovery ventilation with an air-to-air heat pump?

I'm imagining something that could transfer heat from the exhaust duct to the supply duct of the HRV as needed during the heating season and vice-versa in the cooling season. Heat transfer within the HRV would be wholly conventional and the additional heating/cooling would be introduced in the duct supplying air from the HRV to the house.

In Mechanicals | Asked By Interested Onlooker | Mar 5 10
3 Answers

Cathedral ceiling R-value boost

Zone 6. Layers from the outside in:
Galvalume steel roof
Grace advantec
Plywood deck
1 inch air space
1 inch foil faced tuff r
5.5 inch roxul
Rafters are filled at 7.5 inches.. 24oc

Question; what can I put under the roxul and rafters to get r38?

In General questions | Asked By stephen edge | May 17 12
3 Answers

Spray foam in walls

Katrin Klingenberg of PHIUS gave a talk called "Balancing the Investment: Enclosures, Mechanicals, and Renewables" which is available on demand from the Energy Center of Wisconsin.(1) At 25:00, she makes this comment on many houses with spray foam wall insulation applying for Passive House certification: "We have seen applications that are horrendous. The walls are going to be full of water in two years."

In Green products and materials | Asked By David Martin | May 17 12
3 Answers

Airseal but still have a draft from basement

Since I found you guys Ive airsealed my attic and ducts.
I cheaped out our unfinished basement airseal/insulation with foam xps 1" foam sealed edges and r19 batt, the basement will be sealed with rigid foam and plywood eventually as we need the space.
Ive also chalked the baseplate perimeter to the foundation.
I have a Weil Gold cgi with some form of mechanical blower from the side of the boiler outside assuming the air draft is coming in from this as I dont think it opens or closes just starts when the furnace is on

In Green building techniques | Asked By Darren Finch | May 17 12
8 Answers

"Fooling" a tankless hot water heater

In reading the article about the Chautauqua cottage renovation, the author mentioned that low water volume fixtures can "fool" a tankless hot water heater. (presumably not to come on) The author mentioned using a booster tank to help with the problem. Could someone explain what type of a tank this is and how it works?

In Mechanicals | Asked By Joe Cooper | May 3 12
4 Answers

Can an air handler be placed in the garage without an enclosure?

In climate zone 3, under the 2012 Energy Code, can a residential air handler be placed inside of a garage attached to the dwelling?

In Building Code Questions | Asked By henry zuckerman | May 10 12
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