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7 Answers

Are HVAC ducts a factor in heat loss?

I am in the whole house fan business (http://www.invisco.com) and just released an R60 duct adapter. I notice that there is nothing like it for HVAC ducts. Are those ducts too small to be of concern? My design can be used to add insulation to ceiling connections to meet R38, R49 and even R60 for hvac ceiling interfaces if that would be of value.

In Energy efficiency and durability | Asked By Kurt Shafer | Jan 23 12
4 Answers

Insulation for Vented Cathedral Ceiling

Hi all. I know the issue of insulation for cathedral ceilings has been addressed before, but I am still confused by what the best approach is for a vented cathedral. I live in Westchester, NY. We currently have 3 large skylights in our great room. One has developed a bad leak, so we have taken down much of the ceiling and are now considering the choice of fixing them or eliminating them. The beams are 2x10s, which currenly have about 10 inches of fiberglass batts. there is no vent channel against the roof, so I assume the air just moves through the fiberglas.

In Energy efficiency and durability | Asked By Richard Cohn | Jan 24 12
0 Answers

A great new introduction to air sealing

Credit where credit is due: the U.S Department of Energy's Building American program has done a great job with their new introduction to air sealing:
Air Sealing: A Guide for Contractors to Share with Homeowners

Check it out -- it's good.

In Energy efficiency and durability | Asked By Martin Holladay | Jan 24 12
23 Answers

Insulation- rim joist area?

Keeping with the theme of the week-- not-so foamy homes-- I am trying to come up with a solution for insulating a rim joist area with open web floor trusses that does not include foam.

Has anyone tried to wet spray cellulose onto the rim joist between/around the floor trusses? I would imagine that wet sprayed cavities need to be incapsulated on all six sides to avoid settling, but I could wrong about this.

Dense packing the area with insulweb and cellulose would a nightmare-- it would be dang near impossible to fasten the insulweb around the webbing of the floor trusses.

In Energy efficiency and durability | Asked By Brett Moyer | Jan 13 11
4 Answers

Basement rigid insulation

Im installing 2”xps against concrete basement walls using insulation adhesive and foaming gaps. However, bracing the rigid panels while the adhesive sets up is proving time consuming. Can I use a concrete screw and washer to brace the panel? Best practices appreciated.

In Green building techniques | Asked By Frank O | Jan 23 12
7 Answers

Newbie questions


This may be a little odd question for you experts here but I'm making house vs condo considerations and the major factor is the heating costs which are included in the condo maintenance

In General questions | Asked By sam dhak | Jan 20 12
59 Answers

Heat Bridge or 3-Dimensional Pressure Boundary?

I stumbled on this interesting image a while back.
I noticed that the caption refers to "heat bridges from structure and roof fasteners"....
The fastener locations are obvious....
But the linear pattern does not look like a structural pattern(series of wood or steel rafters or joists).
It looks more like a pattern of rigid insulation and the voids between the insulation.

I think the pattern is more likely related to 3-dimensional Air flow as mentioned in this Insight

In Energy efficiency and durability | Asked By John Brooks | Dec 23 11
2 Answers

Are Fi-Wi or Fine Wire Ventilation systems for a Passive house adequate or hyped up?

As the question implies I wonder if any one here has any thoughts on this ventilation system I have come across on a particular site in Ireland. Here's a link to it http://www.viking-house.ie/fine-wire-hrv.html

Here's an extract -

In PassivHaus | Asked By Tim O Brien | Jan 20 12
2 Answers

Hi there, I am a general contractor with a long history of natural building.

I am currently on a design build project of a 1200 sq ft Net Zero Energy home in Santa Cruz, CA area.

We are about to insulate with a closed cell foam product called Spraytite 178. i have been informed of the issue of soy and plant based foams vs. non soy based for a number of years and want the best product for my project/ customer. I am wondering if, in your opinion, there is a significant advantage to any other closed cell foam in my locally available market ?

Thank you!
Michele Landegger

Boa Constructor Building and Design

In Green products and materials | Asked By Michele Landegger | Jan 23 12
1 Answer

Great comic related to green building speak.

What will we run out of first - words or resources?


In General questions | Asked By Ben Wilson | Jan 23 12
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