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0 Answers

Double Wall Opening detail


I am embarking on my first energy efficient home in Maine for my own residence. Walking away from the Code Built norm finds me scratching my head a bit.

Double walls at 14", 2X6 and inner 2X4. Stem walls and footing with an insulated and thermally broken floating slab system.

Sill pan recommendations for the door breaks where they will contact directly with the concrete stem wall? I will be using an EPDM sill gasket/10 mil poly/tremco sealant sandwich under all the sill plates and I assume under the thresholds of the many doors.

Asked By David Chapman | Jul 29 16
3 Answers

Good source for minisplit turndown ratios and turndown vs. HSPF / SEER?


I was going to ask this on this thread:

But realized it was a separate question.

Asked By Keith H | Jul 28 16
1 Answer

Separation of concrete slab and foundation

We removed carpeting in a condo that we own. We noticed by the sliding glass doors a crack in the slab. The slab has a layer of rigid insulation on the perimeter which seems to have seperated from the cinder block foundation. The cinder block wall does not appear to be bowing looking at it from the outside. Is this a big concern or is there a way to fix the problem without ripping everything up?

Asked By Joel Silverman | Jul 29 16
3 Answers

ERV as a bathroom vent fan?

My wife and I are purchasing a new house. House is in NJ and was built in 1987. Stick framing, average to slightly above average construction quality, average energy efficiency as far as we can tell.

For whatever reason, none of the bathrooms have vent fans. Putting fans in is likely to be one of the first projects I do.

Simple question - is an ERV appropriate to use as bathroom ventilation in a not-so-tight house? Our priorities are as follows:

#1 remove moisture to reduce mirror steaming and mold potential
#2 energy efficiency in terms of not wasting heated/cooled air

Asked By Matt Culik | Jul 28 16
5 Answers

Reducing humidity without AC

I live in NJ. Typical summer weather here is highs in the mid-80s/low-90s, lows in the 70s, and very humid.

Our house has a "natural" overnight temperature of about 73. What I mean by this is that if I set the AC to 74 before we go to bed, it cycles on/off until about 3AM, at which point everything has cooled off enough outside that no more AC is required to hold 74.

While this is nice from an electricity use perspective, no AC means the interior air gets stuffy and the humidity starts to creep up.

What is the most energy efficient way to address this?

Asked By Matt Culik | Jul 28 16
13 Answers

Open-cell foam contacting a water heater flue

I have open cell foam being put into my attic. My hot water heater is in the garage below, but where the flue goes through the rafters, is it OK for the open cell foam to contact around the flue? If not, how much of a gap is left around it? I guess they would have to just cut that gap after foaming since the foam isnt going to just cooperate....

Asked By John Sexton | Jul 27 16
9 Answers

ERV + dehumidifier ducting in a minisplit house

I'm working on a 2400sf house (CZ4, but very nearly 3) where the owners have selected minisplits - one ductless 1st floor, one ducted w/ very short runs for each of 2nd & 3rd. So there will be no major duct lines throughout the house for heatning and AC. They've also chosen to go the ERV and Dehumidifier route, this being the humid southeast.

Asked By Chris B | Jul 28 16
11 Answers

Minisplit retrofit in Climate Zone 2

I'm trying to figure out how to use a minisplit system on a retrofit project. I got a quote from an HVAC company (recommended by the equipment rep), but some of their opinions don't make sense...which brings me here today.

The HVAC company proposed 4 zones with a 3 Ton compressor outside:
1 ducted 9k unit in attic, serving Guest Bath, Guest Bed, and Office
1 ducted 9k unit in attic serving Master Bed and Bath
1 9k ductless serving kitchen
1 9k ductless serving living

Asked By Green Heron | Jul 26 16
8 Answers

Blown-in insulation for existing walls

My circa 1900 house in West Virginia (Zone 5) has hardwood paneling throughout the interior and wood siding on the exterior with no insulation in-between the actual 2x4 walls. I'm pondering either blow-in cellulose or open cell spray polyurethane foam applied through holes in the siding. (Should I consider other options?) Both open-cell SPF and cellulose show an R-value of 3.2 to 3.8/inch. I understand the cellulose will settle over time leaving some gap at the top and foam will not. I like the idea of an air barrier provided by SPF between the leaky wood interior and exterior surfaces.

Asked By Andy Kerr | Jul 25 16
3 Answers

Aeroseal duct sealant

Hello. My heating and air tech recommended aeroseal to repair leaking duct-work in our walls. We are going to replace duct-work in our attic but looking to this product so we don't have to tear out walls. Does anyone have any experience with this product? It says that is is low voc and a non-volatile vinyl acetate. I realize that sealing small holes is good for using less electricity and producing less dust which in turn produces better air quality but if aeroseal off gasses and eventually degrades overtime then am I just breathing in a different type of pollutant?

Asked By Lori Wilson | Jul 27 16
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