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2 Answers

4" or 6" bath fan duct?

Hi all. Sadly, i have another project so i'm going to be pestering you with dumb questions again...

We are installing two panasonic whispergreen, .3 sone, 80 cfm bath fans. they both have relatively short duct runs that exit through the wall. the inlet on the fan can be either 4" or 6" diameter. i understand the fan will operate at 80cfm regardless of the length or diameter of the duct but which diameter is more energy efficient..?

thanks again

In General questions | Asked By erik olofsson | Sep 16 13
1 Answer

Duct leakage

Looking for some suggestions here.

Had my Energy Star 3.0 final last week, and all tests passed expect for the duct leakage to the outside.
The blower door passed at 1.18 @ 50 pac (was pleased with that), and everything else is fine.

In Mechanicals | Asked By Jesse Lizer | Sep 16 13
2 Answers

Encapsulated batt insulation?

Good morning,,i sent a question in the answer category. not awake yet..

Thanks for reply ..removing the 2x4s woud be to much trouble with al the plumbing and electrical laid out already..what's youre opinion on useing R-13 encapsulated batts for the basement exterior walls..i didnt see anything about that approach...if you suggested the encapsulated batt would work,would i need a extra vapor barrier, being it allready has one..if you dont suggest i have to spring for the closed cell spray foam,,also would i need a vapor barrier for the foam spray
i believe i read it is not needed..thnks

In General questions | Asked By jerry pignato | Sep 15 13
34 Answers

Outside air for woodstove

Been woodstove shopping lately and noticed that "outside air" for woodstoves is done in a couple of different ways. The European stoves in general do not seem to have a direct connection for the outside air duct--it's what the salespeople are calling "proximity" air, meaning a 3" duct from outside terminates very close to the stove, but does not connect. The American stoves are much more likely to have a direct connection. To me, a direct connection makes perfect sense, whereas the "proximity" air looks like an air leak.

What's your experience with this?

In Mechanicals | Asked By David Meiland | Dec 5 11
5 Answers

Can open-web floor truss space be used instead of ductwork for heating/cooling?

I have a already built 3-story 3,800 s.f. colonial Garrison outside of Boston, MA. When we built the home in the late '80s I figured to save money on duct work by not putting in whole house AC. I might have saved then, but I'm going to have to pay now that we are putting in a new HVAC system to replace the oil baseboard heat and window AC.

In General questions | Asked By Mark Valery | Sep 15 13
2 Answers

Is there such a thing as landscaping that helps home insulation?

I live in New Jersey, and have been recently doing some landscaping around the house. Now I know that shade trees helps with sun in the summer, I'm thinking everyone who has sat under a tree in July knows this.

In General questions | Asked By Dan N | Sep 16 13
3 Answers

Closed-cell foam / Flash and batt

I am in the process of reinsulating my home. I have a 1,000 sq. ft. flat roof. Under the roof is 6" wide tongue and groove boards attached to a 2 x 6. It's sloped ( -2/12 pitch).

I would like to use a "flash and batt" approach. I'm a little unclear on venting. Does it need venting? Currently I have 2 sides vents and a soffit off the back of the house.

In Energy efficiency and durability | Asked By Gregg Pachik | Sep 11 13
2 Answers

Does Great Stuff shrink?

For 1/2" gaps, should I use Great Stuff or the 2 component foam? Which bonds better, shrinks less?

In Energy efficiency and durability | Asked By John Waller | Sep 15 13
3 Answers

Tiny weekend cabin cathedral ceiling insulation


I have a tiny cabin (12' x 12' with 13.5 ft ceiling). It is used once every two weeks for a weekend.. I have 2x4 walls and 2x6 rafters. My roof is osb with steel panels. My wall cover will be wood stripes.

I did some work to insulate my roof but I think some mistakes where done. I filled every nook with spray foam (from can) including my roof Ridge which had this gap that I am not sure if was vent or not... Also, I filled the eaves with foam around the corners.. My logic was air tightness.

In Green building techniques | Asked By Uri Gonen | Sep 15 13
6 Answers

New construction window advice, please

Hello Everyone,

In General questions | Asked By John Guzzo | Sep 14 13
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