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7 Answers

If a home is too tight and does not have provided mechanical ventilation, can it draw in humidity and excessive heat during peak times?

I have a customer that purchased a home eight months ago and all summer long he has complained to the builder that the temperature and humidity levels are way too high. I performed a blower door test and found that the home is 2000 cfm lower on infiltration than what BPI recommends.

In Mechanicals | Asked By matt tucker | Aug 13 13
0 Answers

I'm looking for a green architect/designer/contractor in the San Francisco/East Bay area

I am doing a single family home reno in Lafayette, CA and want professionals who are up on building science ... roofing, infiltration, insulation, etc. You may recommend yourself if you think you qualify. You may email me direct at ballerina4hire-cashonly@yahoo.com, if you prefer. No spam please.

In General questions | Asked By Joe Karen | Aug 13 13
4 Answers

What type of water heater and where?

I was planning to install an electric heat pump water heater in my new house. I really liked what I read about the Airgenerate ati66. But apparently so do a lot of other people. The ati66 is in short supply and not distributed in my region. I can possibly buy one and have it shipped from the West coast.

I could possible substitute an AO Smith Voltrex 80 gallon. It would be easier to source and support than the Airgenerate.

In Mechanicals | Asked By Steven Knapp | Aug 12 13
8 Answers

Heating a cold-climate off-grid superinsulated house

The house will be in New England, northern zone 5, high elevation, open to north winds. Good southern exposure but lots of windows for north view. Cathedral ceilings up to 18-20. Proposed insulation R40 walls, R65 roof, triple glazed European windows; very tight. (<1.0ACH50) There will be a PV system with battery back up and possibly solar thermal.

Do minisplits work for off grid situations? Solar thermal with radiant wall heaters? Anyone have experience with superinsulated off grid homes in this climate?

In Mechanicals | Asked By Bob Irving | Aug 11 13
15 Answers

Make an unvented semi-conditioned space around air handler and ducts in attic?

If the builder can use rafters instead of roof trusses, I want to make the attic space around the air handler and ducts semi-conditioned by putting rigid foam board on underside of rafters, and buttoning up the envelope completely, leaving the space behind the foam to be vented by soffit and ridge vents.

In Energy efficiency and durability | Asked By rob clark | Aug 8 13
2 Answers

Solar vapour drive a concern?

How risky is solar vapour drive in zone 6 toronto which experiences hot humid summers? And increasing occurences of severe thunderstorms? Have what I think is a non-resevoir cladding (2 metal skins with polyiso foamed in btw like a SIP but dependent on caulking at joints, over 2" mineral wool, Tyvek Drainwrap, plywood, 2x6 with mineral wool batt, ? and drywall. Not sure of Tyvek and whether ? layer is needed. Thx.

In Green building techniques | Asked By Jerry Chwang | Aug 10 13
4 Answers

Will installing Optima fiberglass (closed system) stop the ice damming?

I live in Madison, Wisconsin. I have a cathedral ceiling with 2"x 8" rafters. The interior is a wood ceiling attached to plywood. I have contacted an insulation contractor and stated I would like to remove the shingles & roof sheathing. He said once I did that, he would seal all air penetrations areas and then install blown Optima fiberglass insulation into the 2"x 8" ceiling rafters using the BiBs method.

After the Insulation was done, I was going to replace the sheathing and put Ice and Water Shield over the whole area.

In Energy efficiency and durability | Asked By Dave Heinzelman | Aug 11 13
3 Answers

Will a Mitsubishi heat pump system be efficient for winter heating?

I have a second home in East Otis, MA 01029, and plan to install a heat pump system. The home is vacant during the winter and the heat is kept at 50 degrees and have an oil hot water system for heat.

Will the heat pump system be effective in heating the main part of the house as it will be effective in cooling during the summer months? Thank you.

In Energy efficiency and durability | Asked By Albert Gabbay | Aug 10 13
6 Answers

Another foam sandwich question: retrofit options

First, I am a DIYer. There is no pro involved. That said, I try very hard to educate myself...

I'm in the process of upgrading windows 1 by 1 in my house. When I do this work, I've begun to take the approach of stripping all drywall, polyE, and existing (generally poorly installed) fb batts. I then custom cut and foam in polyiso foam board and don't replace the polyE. However, the house also has 1" of XPS outsulation with an interior-to-the-XPS 1.5" air gap and someday, when the stucco gets redone, I'll probably put more outsulation on. Stucco is directly on the XPS.

In Energy efficiency and durability | Asked By Keith Hoffman | Aug 11 13
1 Answer

Spelling police

This ad (see screen capture, below) ran on GBA this morning. “Efflorescence” doesn't have a “u.” Fluorescent lamps. Efflorescence. They say it comes from the French for flowering, but that would be “effleurescence,” which it ain’t, in French or in English.

And besides, the building science is a lousy as the spelling. It should say, “Is this your basement? Get the downspout water away from the foundation.” Wouldn’t sell product, though. Oh well.

The misspelling is not a big deal. But people thinking they need to buy a product to solve a wet basement corner — that’s a bigger problem.

In General questions | Asked By Martin Holladay | Aug 12 13
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