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4 Answers

GSHP Vs whole-home dehumidifier


I am looking at retrofitting my home with a GSHP (please see the below thread for details):


I am also planning to have an HRV and a whole home dehumidifier (Lennox 65-pint) installed as part of the new setup. My question is:

In Energy efficiency and durability | Asked By Venkat Y | Jul 23 12
6 Answers

Insulating recessed lights where there is no attic

I have an interesting problem. We have seventeen, 6" recessed lights in a ceiling that has no attic above it. We conducted an energy audit (we're putting in a 9 kw solar system and a host of other related changes) and found these to be a serious source of energy loss. The area where these are located is a single story, family room that just has the heat sucked out of it in the winter. These recessed lights are like chimneys.
While I am replacing most of our recessed lights with LED's, this one area I haven't touched as I need to insulate first

In Energy efficiency and durability | Asked By Alex HIllman | Jul 29 12
1 Answer

High solar gain windows in NJ?

I'm building a super-insulated house, 12" cellulose filled double-wall in South Jersey, R60 roof. I think the HDD are about 5000 and the CDD are about 1000. Should I be using high solar gain windows? Would they be cost effective?

In Green building techniques | Asked By Michael Arnold | Jul 29 12
4 Answers

Construction-detail Drawing Library

Would love to see drawings pertaining to double-stud walls or links to other resources providing these details. Any plans to create a library section dedicated to this subject?

In Green building techniques | Asked By ken dupuis | Jul 27 12
5 Answers

Earth tube for make-up air

I am planing on building a very tight house. Before I ever heard of "earth tubes" I was planing on providing make-up air. About 90 feet from the home I am going to build an out building. On this outbuilding on an exterior wall i was going to build a box that would hold a furnace filter from which I was planning on using 6" s&d pipe to run down 8' into the ground & then over to the house from where it would come up into a chimney chase & ultimately exit at the top of the conditioned attic space.

In Mechanicals | Asked By Eric Mikkelsen | Jul 28 12
3 Answers

Wet Spray Cellulose Dry Time

I'm building a house in Maine, we recently did a wet spray cellulose installation in the wall cavities, its a 2x6 wall with zip sheathing and 2 inches of poly iso on the exterior. We installed about 2 weeks ago and the cellulose is still very damp. I was told to drywall to prevent the cellulose from absorbing more moisture. I'm concerned about possible mold in the damp dark wall cavities. Any thoughts?

In Green building techniques | Asked By Mark Hinkley | Jul 26 12
1 Answer

Insulation refit and balancing the insulation.

House located in zone 2A, off the ground ~ 2 feet (1800 sq ft). The house has a sloped metal roof with 2 x 6 rafters on 24 inch centers and 2 x 4 stud walls on 16 inch centers. Currently there is no insulation in the walls or floor and 5 1/2 inches of fiberglass on the attic floor.

Attic Unvented (~R30) 5 1/2 inch fiberglass batt with 2 inches of rigid poly iso foam.
Walls (~R20) 3 1/2 inch fiberglass batt with 1 1/2 inches of rigid poly iso foam.
Floor (~(R13) 2 inches of closed cell foam.
Windows triple pane low e argon gas filled.

In Plans Review | Asked By David McMillan | Jul 28 12
1 Answer

How to insulate a basement wall rim joist that is an inaccessible "cavity"?

Baltimore, zone 4A

In Green building techniques | Asked By richard Ugarte | Jul 27 12
5 Answers

Ooops... where's the air barrier?

Here in WA state we now have blower door testing required for new homes, and they have to meet a fairly lax standard. As expected, a lot of folks aren't clear on what air leakage is and how to build tight. Got a call yesterday from a man with a new owner/builder home underway, insulation just installed, and he wants to know about testing. He intends to put T&G wood on all walls and ceilings. The building inspector advised him that he would need 4-mil poly as a VB if he wasn't going to have drywall with VB primer.

In Energy efficiency and durability | Asked By David Meiland | Jul 27 12
23 Answers

How do I detail unfinished wood rainscreen siding?

I don't like the idea of paint, stain, or wood preservatives. They're expensive, a lot of work, and often toxic. Unshaped, wood boards are available, durable, relatively cheap, and easy to replace. Of all the siding options, unfinished wood benefits the most from a rainscreen, yet is proving to be very difficult to detail.

Two ways of installing board siding in a rainscreen fashion is vertically "board and batten" style, or horizontally as clap boards.

In Green building techniques | Asked By Richard Baumgarten | Jul 24 12
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