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2 Answers

ERV-Minisplit combo vs. Magic Box

We are conducting a deep energy retrofit on our two unit building (each unit 1,500 sf) in Chicago (zone 5a). I am pretty much done with the first floor and chose the ERV-Minisplit combo to primarily address our ventilation needs, cooling needs and summer dehumidification. And it appears to work well (Recoupaerator and one 12,000 Btu Fujitsu Minisplit): Winter time humidity around 40%, summer time humidity around 55%.

Asked By Marcus de la fleur | Jul 26 16
3 Answers

Polyurethane foam vs. Icynene foam: What's best for subfloor insulation?

I have a house that is brick veneer and the front section has the polished timber floors.
The sub floor area was not properly ventilated and we had some mould issues. Since then we have had vent’s installed and a sub floor fan under one of the rooms.
However it is a clay soil that the house is suspended on, there are still a some mould spurs on the soil. The air under one room is always quiet damp.

I was wondering if product is more suitable for this type of application ….does notabsorb the moisture in the air and will mould grow on it ??

Asked By Rheems I | Jul 25 16
8 Answers

1903 home, first time with central air, lots of questions about insulating, ductwork, etc

Hello! Grab a cup of coffee and hopefully you will have a little insight on this! Thank you!!!!!!!!!!!!!!

I have an early 1900s 2 story victorian home 2200 sq ft, currently getting a new roof next month, and had to remove the old insulation on the attic floor that was outdated in roof preparation (in april). Blown in insulation was added to all exterior walls, as well as a thin sheet of foam fiberglass insulation, prior to installing vinyl siding over the wood siding about 25 years ago. Also storm windows to cover the old windows.

Asked By John Friend | Jul 25 16
9 Answers

Will positive pressure work to vent an attic (i.e., blowing air in)? Attics exhaust fans are a bad idea. But what about blowing air in (using positive pressure).

My father is interested in removing heat from his attic to try to keep the upstairs of his house somewhat cooler. I have advised him that generally speaking, attic fans are a bad idea, which he has come to terms with. However, with that understanding that creating negative pressure in the attic can cause all kinds of problems (sucking out air from the conditioned space, possible back-drafting of combustion appliances, etc.), he has come up with the idea to blow air into the attic instead (i.e., creating positive pressure) to force the hot air out.

Asked By Erica Downs | Aug 12 12
0 Answers

I have a 1950 brick clad house and want to improve the wall insulation.

There is an air gap between the brick and the sheathing (shiplap) but no weep holes are apparent at the top or the bottom. In most place the brick appears to be sitting on the concrete foundation in a bed of mortar. In some areas there is a strip of what appears to be metal between the brick and the foundation. The lone area where the interior wall has been opened has about an inch to an inch and a half of faced fiberglass - facing is to the interior. There is extensive overhang with the roof.

Asked By Andrea Quimby | Jul 23 16
20 Answers

Ramblings on thermal mass, AC and window fans

This is isn't really a specific question so feel free to offer random thoughts

Asked By Alan B | Jul 10 16
1 Answer

Insulating a sloped ceiling

I have a 1.5 story home built in 1900 in southern NH. Minimal insulation on attic floor and some stuffed into the sloped ceiling from the attic. The insulation contractors that have looked at it want to dense pack the bays on the sloped part with cellulose. One said he could flash it with spray foam to seal it first, then dense pack. I have read that insulating with no venting is a bad idea. I understand without ripping the drywall down, it would be very difficult to insulate properly and add vent chutes.

Asked By Frank Mengler | Jul 22 16
2 Answers

Exterior and interior foundation insulation crossover

Hey All,
In the process of adding exterior insulation to foundation wall but am having an issue in a spot in the backyard where there is a new patio and front yard with a deck. My wife would rather i not rip out a brand new patio and new deck to insulate the foundation. So i was wondering if it would be better then nothing to in those areas put the insulation on the interior of the block and just have an overlap of say 10 feet where there is both exterior and interior insulation?


Asked By Chris King | Jul 22 16
1 Answer

Exterior foam over 2 layers of siding a bad idea?

Zone 7, 100 year old house has 2 layers of siding. The original siding has lead paint of course. The outer siding won't hold paint. Was insulated in the 70s with formaldehyde foam injected into the wall cavities. Current plan is to use SPF as external insulation, using vertical furring strips embedded in the SPF to secure the new siding. The inner siding has a 4" reveal while the outer is more like 12" reveal. There are vertical furring strips between the 2 layers of siding which creates an air gap.

Asked By Tim Lange | Jul 21 16
10 Answers

What is the best way to attach the sub-slab vapor barrier to the walls?

In regards to laying the 6 mil poly vapor barrier down prior to pouring the concrete slab...

Should the poly wrap up the side walls higher than the concrete floor level, and then be attached to the walls with caulk & furring strips that are anchored to the walls with Ramset nails?

- or-

Should the poly just barely wrap up the side wall, and be taped to the wall (with Tyvek tape or similar) so that the poly and tape are encased in concrete after the floor pour?

-or perhaps this connection is unimportant, as the slab will get caulked on this slab-to-wall joint

Asked By Adam Peterson | Jul 20 16
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