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4 Answers

DIY heat recovery and ventilation question

Ok..so it's been a while. We completely destroyed and then rebuilt our 1800s house and aside from some trim and exterior improvements...we have been comfortably living in it now for over a year with many thanks from this site. We used the cut and cobble insulation system combined with blow in with a mooney wall to keep our house very energy efficient. Even in the deep cold of winter our heat bills are below 100 bucks in a 1400 square foot house built over 135 years ago.

Asked By Geoffrey Cook | Aug 24 16
4 Answers

Options to make space for exterior insulation

This is my first post so thanks in advance for any input. I’m finalizing the plans for our new home with in Kentucky, and I’m talking through the option of adding 2” of Roxul Comfortboard on the outside of ZIP wall sheathing with the builder. He has never done this before, and one of the objections he is raising is that it would require making the foundation/basement walls 2” thicker to make room for this since we are already planning on a brick cladding.

Asked By Brad White | Aug 26 16
0 Answers

Can you use rigid insulation only? Exterior wall in zone 1

We are enclosing a screened porch, reinforcing exterior walls on a 1969 trailer and then we plan on putting up rigid insulation over plywood sheathing and existing aluminum

Asked By Jennifer Earp | Aug 27 16
9 Answers

Insulating a finished garage with unvented cathedral ceiling

Hello -

I am hoping for any input/advice about insulating my garage, which I'm in the process of finishing. The details are:

This is a 20 x 20 garage, uninsulated concrete slab floor with an epoxy finish on it. Unvented roof which will have drywall up to the peak. The walls are ordinary 2x4, the ceiling is 2x6. The garage has several windows, all double-page argon/low-E and a insulated garage door that seals surprisingly well (but it's still a garage door).

This is in Denver, CO zone 5.

Asked By Dave H | Aug 9 16
0 Answers

Condensation on soffits after painting

I have a split-level house that has an second-floor overhang with soffits where the a/c ducts terminate to supply the 2nd floor with a/c and heat. We repainted the exterior of the house a week ago and now exterior condensation is forming on the soffits directly below the a/c vents. I've lived in the house for 10 years and we never had any issue like this that I'm aware of. This condensation keeps the paint from drying/curing. What should I do?

Asked By Buzz Mershon | Aug 27 16
2 Answers

“Smooth” flex duct

I understand that flex duct is bad in most situations--it decreases blower efficiency and just generally impedes air flow. That said, for a longish (25ft) run of 6" duct, I wonder if it wouldn't be okay to use one of the 'smooth wall' plastic ducts on the market (see http://www.flexaust.com/product/grass-collection-vacuum-hose/) for a good example of what I'm looking at. This would be in a relatively low-pressure type of situation (Minotair hybrid HVAC system installation).

Asked By Jonathan Nagar | Aug 26 16
2 Answers

ERV and humidity

This is more for my own curiosity.

I've read that ERV's are generally suggested for warm humid climates and I've also read they can cause humidity levels to rise within a home. My understanding is that with an ERV some moisture is transferred from the stream that contains higher levels of moisture to the stream that contains less. Does the system medium look to balance the amount of humidity between both streams?

Example, Stream A is at 40% RH , Stream B is at 20% RH, ~10% is transferred from A to B where both end up at ~30% RH)

Asked By Chris M | Aug 25 16
6 Answers

Following up on the musty smell in our crawl space

Editor's note: This is a follow-up to a previous thread on GBA. The previous thread was Why do I have a musty mildew type smell in my conditioned crawl space?

Asked By Linda Larochelle | Aug 26 16
3 Answers

Questions about minisplits and Manual J

Is it possible for someone to provide me with a a manual J online without visiting my home? I cannot find anyone in my area who I feel is qualified.

I can provide whatever info is needed. I've drawn details sketches of all measurements of my home. I've had a blower door test. I know the insulation levels.

We are planning on making improvements over time, however. But I'm interested in a current calculation based on what I have right now. And then as I make improvements I can see how it will adjust the load requirement.

Asked By Ryan O'Rourke | Aug 27 16
2 Answers

Gluing polyiso to metal and plywood

Hey everyone -

I'm planning to convert the floor of a van, adding polyiso insulation and plywood

My question is about the best product(s) to use - I'd rather not screw the plywood into the van floor so glue will have to provide all the needed support (and survive through all of the vibrations and bumps)

First layer: 1/2" polyiso, glued to the van floor (metal)
Second layer: 1" polyiso glued to the bottom polyiso layer
Third layer: 1/2" plywood glued to the second polyiso layer

So far considering 3M 90, The Great Stuff, and / or the Loctite PL300 Foam Board Adhesive

Asked By Brian Keefe | Aug 26 16
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