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12 Answers

Ventless heat pump clothes dryer

Would a ventless heat pump dryer contribute to indoor humidity and heat levels?

I thought the unit was all self-contained and would NOT contribute to increasing moisture and heat in the room it was located in. If anything, it would only dispense water from the drain line into a sink drain but that's about it. Am I wrong?

In General questions | Asked By Peter L | Sep 5 14
2 Answers

How to insulate a partially open unvented ceiling/roof?

We've had a leak and ceiling damage in a 50 yr old house with a flat roof in zone 4A. Part of the ceiling is gone, damaged, part still intact with its fiberglass.So there are cavities with part fiberglass. There is no ventilation in the cavities. This part of the roof was re-roofed a few years ago and some sort of foam board was added on the exterior (presumably between the old rubber and new TPO) at that time. The is no condensation currently with the cavities open.

In Green building techniques | Asked By Katie Dorst | Jan 23 15
13 Answers

Using too much electricity?

I just completed a 1043 sq ft story and a half cottage with a 351 sq ft garage apartment over a detached single car garage. I have two mitsubishi hyper heat splits in the cottage and one in the garage apartment. The cottage has a 27KW ecosmart tankless and the garage apartment has an 18KW. The garage apartment is never used and my usage is between 60 and 74 KWH per day. I'm gearing up to call the utility and the electrician to check things out. Is this atypical for an all electric home this size?

In Energy efficiency and durability | Asked By Andre Jones | Jan 19 15
1 Answer

Advice for basement wall and flooring on an uninsulated basement slab

I am insulated a basement with a very low head room and cannot add any insulation to the floor. I am insulating the exterior walls and I have a trench drain and sump on the interior perimeter of the basement. This had been installed before moving in to the house. No water has shown up in the basement in the last 4 years.

The walls are fieldstone and I intend to use spray foam and provide a dimple mat along the fieldstone wall to funnel any water into the trench at the perimeter. Not sure if this dimple mat should go up the side completely or not.

In Green building techniques | Asked By E M | Jan 22 15
4 Answers

Air sealing for unvented cathedral ceiling

I am planning a remodel which will add a cathedral ceiling,and there is already an existing cathedral ceiling in another part of my home. Since much of the roof will already be removed this seems like a good time to correctly insulate and air seal.On this site (thank you Martin et.al.) the outer layer of rigid insulation is taped at the seams. On the BuildingScience site (thank you Joe et.al.) the unvented compact roof shows self-sealing membrane over the structural roof deck for an air barrier. Somewhere else I read the suggestion to use tape on the seams of the structural sheathing.

In Energy efficiency and durability | Asked By Eric West | Aug 28 13
4 Answers

DC vs. AC lighting, etc.

Hi there,

In General questions | Asked By jonathan nagar | Jan 22 15
9 Answers

Humidity question

I live in southern Ontario (think Buffalo) and moved here last year. The house had a 80% efficient furnace that used indoor air for combustion, the house had 17.68 ACH50, with the majority of the air leakage through the crawlspace (under 1/3 of house) and non existent attic hatch (above 1/3 of the house, above the crawlspace house extension ironically). The indoor humidity last winter was 25-30%, i gave up in trying to raise it.

In Energy efficiency and durability | Asked By Alan B | Jan 19 15
2 Answers

Energy savings contributed by windows & appliances

I am deciding to go for a building envelop. Can anyone guide me what could be the possible savings and its contribution to energy efficiency for both building and other appliances?

In Energy efficiency and durability | Asked By Rahul Sharma | Jan 23 15
3 Answers

Ever since I got new windows, doors and a vent put in, it is freezing, there is an awful draft

Ever since I got new windows, doors, and a vent put in, it is freezing, there is an awful draft, and even when the fire is lit it is cold. I cannot keep the heat in the house even with the fire and radiators going. There is no heat staying in. I can feel a constant draft blowing all the time.

In Energy efficiency and durability | Asked By jenny sinnott | Jan 23 15
26 Answers

Closed crawlspace with dehumidifier and foundation insulation

I am still in the planning stages of building my new house. I would like a closed crawlspace (I'm in a mixed humid climate) with a dehumidifier and foundation wall insulation. See page 35 (which is actually page 41 on the pdf page counter) http://www.advancedenergy.org/portal/crawl_spaces/pdfs/Closed%20Crawl%20... for a sample design of what I'm going with. I have two main questions about this design choice:

In Energy efficiency and durability | Asked By Michael Geoghegan | Oct 27 14
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