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13 Answers

Does anyone have experience with Zehnder ComfoFlex?

We are building a new house and in the final stages of design. The design includes an HRV and Zehnder ComfoTube looked great until I discovered that it is not UL listed. So, I'm curious if anyone can provide feedback on ComfoFlex. There isn't much on the intertubes...

Asked By Trevor Fontaine | Feb 9 16
3 Answers

How to work with a very deep truss in vaulted ceiling.

Hello dear friends, as you will see in the attached drawing I am looking at about an 8 foot run of 22" deep truss over my living roof before my ceiling flattens out to catch the height of the second story ceiling in the back of the house.

Asked By Barry Reicker | Jun 29 16
0 Answers

Insulating above a garage roof

Location: Western NC, zone 4, mixed humid
Elevation 2000 ft
Roof: slope 2:12, standing seam.
Attic: formed with trusses and unvented
House roof insulation: Polyiso nailbase R15 min above the deck, netted BIBs below.

Asked By Jeremy Turner | Jun 30 16
0 Answers

Trying to source 3/4 inch thick coroplast in Maine

Has anyone had luck in sourcing thicker coroplast sheets near Maine?
The one sign maker i contacted said his vendor will only supply full units and not single 4x8 sheets...

Asked By kevin freeman | Jun 30 16
1 Answer

woodshop super-ventilation: Any reason to air seal / insulate?

I'm building a 900 sqft woodshop outside of Portland, OR (Climate Zone 4c).

Based on Bill Pentz's research, the best way to avoid fine dust-related health problems is to ventilate all sanding/cutting tools to the outside with ~ 1000 CFM of air, which is enough flow to fully change the shop air every 7 minutes.
Recirculating air filters don't cut it for fine dust --- it has to vent outside.

Taking this airflow as a given, is there any reason to:

1) Worry about air-sealing the shop wall envelope? (There will be an open garage door or intake fan providing makeup air.)

Asked By Kevin Lynagh | Jun 30 16
0 Answers

Vapor barrier

Am looking into building ICF homes in another country. My question is they do not generally heat and air condition their homes due to high energy cost. It is warm and humid and am not sure what, if any vapor barrier should be used in the roof area.

Asked By Thomas Webster | Jun 29 16
17 Answers

R-values of ceiling and walls

Zone 5a (on the border of zone 4)
Existing uninsulated concrete slab.
No basement. 2x4 frame.
A bunch of newbie questions.

http://www.homepower.com/insulation-zones
Why is the insulation recommendation for an attic so much higher than for an cathedral ceiling?
Both are the shell of the building but the attic has an ceiling under it that at least adds some insulation value. I would expect the recommendations to be closer or even reversed.

Many sites stress the importance of a high R-value to save energy.

Asked By Tony Tibbar | Jun 3 16
31 Answers

Direct vent vs. power vent gas water heaters

A recent blower door test/audit has alerted me to the fact that my natural draft hot water heater can backdraft in worse case scenarios (range hood/clothes dryer/bath fan on). It seems to reverse back to a correct draft after a few minutes. It's only about 6 yrs old, so I hate to replace it, but not as much as I hate the idea of the back draft.

Asked By Erik Addy | Mar 8 16
8 Answers

Is a dehumidifier needed in a tight house?

I've read several times that it's common for tight, well-insulated homes to need supplemental dehumidification, as the AC doesn't run enough to dehumidify the home.
As a person who is especially sensitive to humidity, I'm very interested in this.
I wonder if an equal level of comfort can be achieved more economically with a higher temp. set point but lower humidity. (In my case, Chicago area- warm and humid in the summer).

Asked By Ben Rush | Jun 27 16
2 Answers

Best practice for extending out a wall

Hi GBA,

I have a 2nd floor gable end wall which is constructed of (from outside) brick, air gap, block, air gap, 3/4" plaster/blueboard. There is no framing/insulation in the wall. We are converting an existing closet to an opening and to part of the above wall will be furred out with 2x4's. I would like to insulate it while we are in there but as always don't want to create issues.

Asked By G S | Jun 29 16
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