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2 Answers

ERV - where does the moisture go?

I understand the difference betwen an HRV and an ERV - that the HRV transfers heat between the incoming and outgoing air while an ERV transfers both heat and moisture. I am puzzled as to how, in a house with an ERV, the moisture generated by bathrooms, laundry, people, dogs etc actually leaves the building if it is transferred to the incoming airflow ? Also, what stops odors being transferred between outgoing and incoming air ? I haven't mentioned cooking because I'm assuming a range hood with its own make-up air will be used.


Asked By Peter Hastings | Nov 18 14
0 Answers

Brands of HRV?

Anyone have any experience with either Lifebreath or Imperial HRVs? My architect specified Zehnder, but my HVAC guy has installed Lifebreath and Imperial, but not Zehnder.

Asked By stephen sheehy | Nov 17 14
5 Answers

Minisplits in the humid southeast?

I'm currently working on design for a house in the southeast, on the border between climate zones 3 and 4 (officially 4). Tight site, 700sf footprint, 3 floors over a walk out, unfinished but minimally conditioned basement.

Wall composition isn't settled yet, though the minimum is likely 2x6 studs with blown cellulose or open cell foam and 2" exterior xps. Basement is possibly thermomass if the numbers shake out OK. Given the small footprint and envelope, I'm hopeful that we can opt for decent walls, roof, and windows.

Asked By Chris B | Nov 17 14
13 Answers

What are the potential problems in an open-cell foam sealed attic when voids and inconsistencies exist?

Along with the open-cell insulation, a radiant barrier roof sheathing was utilized. In most cases, half of the roof framing member (12" TGI truss & 2" X 10" out-looker) surfaces are not encapsulated. There are potential areas where exterior wood framed attic walls are not insulated or sealed off from the attic space. The foam insulation was applied after A/C duct and Can lighting fixtures were in place between the framing members. Most ceilings are cathedral with a tongue & groove wood finish.

Asked By Michael King | Nov 11 14
2 Answers

When installing fiberglass batts which is the correct method?

I've always folded the paper flanges over each other on the stud & stapled.
I've seen some videos on You tube from major companies showing them stapling the flanges on the inside of the studs. It doesn't seem right to me. It compresses the batt, & seems like it allows air leakage.I've always thought that if the flanges overlapped you get abetter seal & vapor barrier.
Which is the best way?

Asked By roger steinbrink | Nov 17 14
26 Answers

Imagine a house fire without fire. You better read this article energy misers!

Take the time today to read, study, and learn as much as you can about today’s modern building construction, the impact of ventilation on residential structures, and many of the other topics available through UL-FSRI. Be prepared to change, alter, or adapt your tactics when necessary.

Asked By Richard Beyer | Nov 14 14
2 Answers

Windows yes, but what about doors?

I was wondering if doors in the US are also rated like windows (at least in europe) for air leakage, etc?

Any tips on reasonably priced (maybe to much to wish for) exterior door manufacturers that do a good job on air sealing their units?

I build in Northern Zone 3.

Asked By leo kloop | Nov 17 14
5 Answers

What's the best wall height for a ductless mini split heat pump?

Hello out there,

Asked By Theresa Spear | Oct 26 14
2 Answers

Question from the field... performance after cutting spray foam

Hey all,

I'm a contractor interested in building performance. It's common practice that after installing windows and doors, you spray foam to seal the rough opening. This then gets cut back to accept drywall/trim/siding.

I've always wondered if cutting the spray foam affects the spray foam's performance? Before cutting, the foam develops a nice hard skin and it seems to me that doing away with this might be a bad thing. Is there any data on this?



Asked By Steve Hull | Nov 16 14
1 Answer

Water control at foundation - placement of perimeter drainage


Asked By Lucyna de Barbaro | Nov 16 14
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