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11 Answers

Most energy-efficient ERV?

I'm planning a net-zero energy home built from SIPs, and am trying to size my PV system accordingly. Unfortunately, I'm finding that the ERV that the home needs eats electrons with relish (one model, if run at the highest setting, will consume about 6 kWh per day if it runs continuously). That said, I don't understand the workings of an ERV to know if it does run continuously or cycles, or what the average daily electricity consumption is. I'm hoping folks on this forum can share their insights.

In Mechanicals | Asked By Claire Anderson | Sep 16 09
9 Answers

Condensation Problem

I decided to liven up this gloomy winter day in the Mid-South, by posting about a problem I recently encountered. I am just posting the information pertaining to the problem and will not add my two cents about the possible solution until we see what others think about this. Pictures are attached.


In General questions | Asked By Grant Dorris | Jan 13 11
1 Answer

Lingering Odor after using 0 VOC Paint

I live in Zone 4C near Seattle.

I painted a bedroom with Benjamin Moore Natura 0 VOC Paint about 35 days ago. I painted two coats of a green color waiting the required time between coats. It was the first time I had used this paint. My wife and I didn't like the color so two days later I repainted it white, again waiting the required time between coats.

In Green products and materials | Asked By Kevin Larsson | Jul 3 12
8 Answers

How to ventilate a hip roof

We are going to be replacing the roof on our house as part of a project to make the house more energy efficient as well as an addition and remodel. I live in NJ - a little bit north of central, so we have pretty good swings in climate between summer and winter. The house has a shallow hip roof, and the house is 42' wide and 26' deep. There are nice large overhangs at the eaves, and we will be putting in lots of venting there, but the question is what to do at the top. There is an old existing power fan, two passive vents and a ridge vent.

In Energy efficiency and durability | Asked By Eric Lavitsky | Jun 27 12
6 Answers

Air-Entrained Concrete Walls?

Has anyone used air-entrained concrete for foundation walls in a cold climate? I don't mean the "Krete" products. The reported R-values are R-3.9 as opposed to regular concretes R-0.08. For an 8" wall you are going to get somewhere around R-30? From reading around a bit it seems you can get a 20mpa (3000#) air entrained concrete mix with 6% air. I wonder what the extra cost would be...would it be worth it from an insulation perspective?


In Energy efficiency and durability | Asked By Tim Shepp | Jul 2 12
7 Answers

I have a friend who is remodeling his attic in Columbia, SC and his builder is telling him that all he needs for insulation

is 5.5 inches ofopen cell spray foam and that this will perform at R49. Of course his existing rafters happen to 2x6s. I recomende furring down and blow in netted cellulose or R30C. Any comments

In Energy efficiency and durability | Asked By Kevin Brady | Jul 2 12
0 Answers

conditioning a basement in a super insulated home?

oops, double post. please delete this thread.

In Mechanicals | Asked By Jesse Lizer | Jul 3 12
1 Answer

Suggestions for retrofit insulation in a ceiling with scissor trusses in Very Cold Climate.

I live in Northern Wisconsin (Climate Zone 7).
Here’s my current configuration (exists from when I purchased the house).
Scissor Truss with Roof slope of 4/12 and ceiling slope of 2/12.
Roofing consists of ½” plywood, roofing felt, and asphalt shingles with a vent at the ridge.
Insulation consists of Kraft-faced Fiberglass (estimated at R-20 to R30) stapled to bottom chord of trusses.
Underside of roof deck is ventilated from soffit to ridge.

In Energy efficiency and durability | Asked By Pete Marthaler - Zone 7 | Jul 3 12
0 Answers

Are there any energy retrofit details/drawings for Hydronic-[pipes with fluid in ground] Earth-Tubes to internal heat-exchangers (hx) ?

Earth Coupled Loop (gle) alone to a heat-exchanger/and a blower, etc, or "radiant" using an interior tubing in-floor, etc...?
- for clean Earth-Tube (geothermal piping) to pre-cool or pre-heat a space ??
Or even to a radiant layout just to keep a slab area above freezing (in a barn for an RV, etc.?

In Energy efficiency and durability | Asked By JP Jon Pierce | Jul 3 12
10 Answers

Carpeting over a cold slab: vapor / xps / double plywood

Background: the house was built in 1938 with slab poured between pre-existing foundation walls in 1954, and topped with vinyl asbestos tile. The slab does seem to stay dry all year, but nearby crawl space dirt is always a bit dark and moist. The slab is at grade. Quake contractors reported wetness at the bottom of each drill hole in the foundation nearby. Termites have been active through the slab. Radon is not a problem.

Climate: San Francisco Bay Area fog zone. It is a heating climate with chilly days possible all year, and only a few hot days ever.

In Green building techniques | Asked By Bryce Nesbitt | Jun 9 12
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