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0 Answers
Make-Up Air Heaters to Balance a Range Hood

I'll be breaking ground this Fall for a new home in Maine that will be small (1,197 sq ft) and super-insulated. Heatload requirements are between 10,800 and 12,000 Btu/h in the dead of a Maine winter to keep the place at around 72F. One challenge I'm facing is maintaining the thermal efficiency of the home when using a gas range top and ventilation hood on a regular basis.

In Mechanicals | Asked By Litawyn Eco-Cottage | Feb 3 12
24 Answers
Smallest ERV unit vs. RecoupAerator

We have a small home (1320 sq ft) in SW Wisconsin, and we are bermed into the hill and using a tight envelope with passive solar, high thermal mass and radiant floor heat (that we may not use very much).

We are going to put in the ductwork for an ERV because of what I've read about air quality and our concerns about humidity control.

In Mechanicals | Asked By sheri | Jul 28 10
1 Answer
Dr. Wolfgang Feist responds to questions about the Rideau Residences

On February 3, 2012, Dr. Wolfgang Feist issued a written response to questions about the certification of the Rideau Residences.

After I received the statement and posted it here, I received an e-mail informing me that the Passivhaus Institut in Darmstadt is requesting that Dr. Feist's statement not be published.

I am respecting their request, and have therefore removed Dr. Feist's statement.

In PassivHaus | Asked By Martin Holladay | Feb 3 12
44 Answers
"What must we say?"

I stumbled on this ancient video recently and heard a sort-of contrarian statement:
"don't EVER say that hot air rises..because that AIN'T so"
http://www.youtube.com/watch?v=S57nIs503fA&feature=results_video&playnex...
(just watch the first 1:30 minutes)

"What happens is that the less dense air is pushed up by the colder air"

I had never heard it put that way ...hmmm.... very interesting

So yesterday Allison Bailes Posts a Blog on the same subject.

In General questions | Asked By John Brooks | Jan 31 12
12 Answers
A question about straw insulation...

My name is Michael Garrison, a 30 year carpenter with 17 years building experience in Alaska. I had a friend who used straw insulation. The condensation inside the structure caused a mold to develop that put off a gas that caused a serious lung infection and almost killed him. Have you heard of any other instances of this effect? Thank you for your time.

In Energy efficiency and durability | Asked By Michael Garrison | Feb 1 12
1 Answer
Anyone tried HomeSEED yet?

Just saw this yesterday. Looks like an interesting way to explore alternative strategies to meet energy goals.

http://ekotrope.com/products/homeseed/

In General questions | Asked By Larry Burks | Feb 3 12
12 Answers
Rigid Foam on the interior face?

Hi

I am working on plans for a new house and have been looking at a couple of options for the exterior wall assembly. Climate zone 5, coastal, very humid summers. Will probably be forced air heat and central AC for cooling.

Looking for approx. R-40 walls.

I am leaning towards a double 2x4 stud wall filled full with cellulose. I prefer the environmental benefits of cellulose over spray foam and rigid foam. It also seems like detailing/ flashing at windows/ doors etc are much easier with a double stud wall than rigid foam on the exterior.

In Energy efficiency and durability | Asked By Chris Harris | Feb 2 12
1 Answer
Exterior Rigid Insulation and Siding

Hi,
I recently completed a single family home in Va with 6" stud walls (cellulose) and exterior rigid insulation. I wanted to have 2" minimum exterior rigid, but the contractor pointed out that the literature on the specified siding (Hardi-Plank) only supported up to 1" rigid insulation. They also did not seem to support a rainscreen detail of any type when rigid insulation was used.

In Green building techniques | Asked By Grayson Jordan | Feb 3 12
0 Answers
A nice TV news report on Alan Gibson's Passivhaus development

Here's a link to an interesting TV news report on Alan Gibson's Passivhaus development in Belfast, Maine:
http://www.wmtw.com/video/30363803/detail.html

Congratulations, Alan -- looks good.

In PassivHaus | Asked By Martin Holladay | Feb 3 12
5 Answers
Spotless HVAC filter

Why would my HVAC filter show absolutely no dirt or dust? It fits tightly and there is no residual dust in the air handler unit. A couple of years ago I found that the top of one of the return runs was never closed in, leaving it open to the mechanical room in which that return was located. I covered the opening with duct board and sealed it with mesh and mastic. The majority of returns are panned (what a joke!) and are not accessable. Those that are accessable, I have also sealed appropriately. The filter may not display dust, but the house sure does! Climate Zone 5.

In Mechanicals | Asked By Chris Brown | Feb 2 12
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