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2 Answers

Uninsulated flex duct: Does it lose its sound-dampening qualities?

I'm working on my HVAC material list. All of my branch lines are short and straight. I see where people suggest flex duct for these applications (if installed correctly) for it's sound dampening benefits. However, I am running the ducts inside soffits, and I want the ducts as small as possible so the soffits don't get too big. Since I am inside the thremal envelope, I don't need insulation. Insulated flex duct adds 2-4" to the overall duct size.

Asked By Clay Whitenack | Sep 24 16
2 Answers

Supplier for small registers and boots for ducted minisplit?

Hi all,

I have a completed manual J, S, D, & T. Now I have to find the different parts an pieces.

Because of the small loads in the house, the ducts and fittings are smaller than what I see in stock at the local big box suppliers. For example, I need 4x4 and 4x6 duct boots and register grilles. Where can I find those size fittings?

Asked By Clay Whitenack | Sep 26 16
7 Answers

Polyiso in bonus room

I'm starting the process of finishing my upstairs I'm located in piedmont of north Carolina. My house is 5 years old I have soffit and Ridge vents 1 dormer simple roof line 2x6 rafters . I found a deal on Craigslist for polyiso the problem is its foIL faced on both sides . My plan was to cut and cobble 3.5" pieces between rafters flush to interior of rafters leaving a 2 inch gap from soffit to Ridge vent then install 3 " polyiso on inside of rafters to adress thermal bridging then 1x3 nailers for sheet rock. Is this a sound plan?

Asked By Eric Teer | Sep 24 16
6 Answers

Condensation on plexiglass?

Hi,

In fall-winter-spring, I have lots of condensation on my double-pane windows. After reading multiple sources on the Internet stating that condensation does not form on acrylic, I fastened a plexiglass sheet on a window to test. I lowered the double-cell cellular shades for the night.

This morning, I realized that the test failed - there was fogging on the bottom part (but no droplets). I guess I read the wrong sources or I did something wrong.

Which one is it?

Thanks for your help!

Asked By Marc Delisle | Sep 25 16
1 Answer

Rain screen detail on chimney box with brick veneer and flashing detail

Building chimney box on peak of roof for chimney pipe and plumbing vent to exit. Thin brick veneer with a rain screen detail. The lid for the chimney box is elevated 1/2" for an air gap with 3.5" down turned legs for weather protection. All good so far, but when I go to install the step flashing on the roof next to the brick and then the cap flashing over that which it's mortared into the grout line, there is now no more ventilation from the bottom of the rain screen as it has been sealed off with the flashing details.

Is this an issue?

Asked By eric Mikkelsen | Sep 24 16
3 Answers

Is HPWH reliability still an issue?

I'm seeing a lot of negative feedback on the reliability of heat-pump water heaters. Are they much more prone to problems than straight resistance heaters? If you had to choose a 50-gallon domestic model, what would you choose?

Asked By Charles Campbell | Sep 23 16
4 Answers

Insulating underneath wood shingles underneath asphalt shingles

Hello!

I've done my research and read quite a few relevant posts and articles here, but I couldn't find an exact match for my situation.

Legend has it that my home was built in 1876 in Philadelphia and moved here to Harrisburg via barge sometime after that. I'm in Climate Zone 5.

My wife and I are looking to build an insulated cathedral ceiling. Yes, I've read the wonderful GBA article :)

Asked By Drew Buglione | Sep 20 16
57 Answers

Mooney floor

I want to put insulation on top of a concrete floor.
A layer of foam + plywood bolted to the concrete has been suggested. (By Dana I think)
While that looks an good option I've been exploring more low cost options.

What about a Mooney wall, flooring variation.
Thinking about 2x4 + 2x4, filled with blown in cellulose. Likely GreenFiber or InsulMax.

Is that a good alternative?

Asked By Tony Tibbar | Aug 6 16
1 Answer

Could a heat pump unit be used to heat a crawl space that is closed in?

I'm thinking about having a heat pump system added to my mobile home. The home is about 1500 sq. ft., with a crawl space about 3 1/2 ft from slab to bottom of the mobile home.
This would help heat the floor above and allow me from leaving my home unoccupied for a time during the winter and only have the heaters keep temps around 56.
Well above 35 degrees.

Could this be done?

Asked By Leonard Klinger | Sep 25 16
4 Answers

How far should poly run up the edge of a monolithic slab on grade?

How far should polyurethane run up the edge of a monolithic slab on grade? If it doesn't run all the way up (as I've seen in some details), should the edge be painted with damp-proofing?

--John

Asked By John Ranson | Aug 21 16
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