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3 Answers

Minisplit design in new construction

Hello, I am in the process of designing my new home build. I have decided on a full ICF house with a goal of high energy efficiency. The house is 2300 sq ft main level living with a 2300 sq ft walkout basement. The home is ranch style 64x36 located in Colorado (Zone 5). I am currently having some hurdles with my HVAC system. I like the idea of doing mini splits in the main level with hydronic radiant heat in the basement slab. The manual J calculations I have done show 19k btu/h for the upstairs and 13k btu/hr for the basement.

In General questions | Asked By Kyler Massey | Apr 27 16
6 Answers

Insulating existing slab on grade - need for sleepers?

After completing a strategy for insulating my slab-on-grade floor (which sits on sand ONLY) as part of a major building renovation in Zone 5a, I discovered the GBA construction detail for the same situation here: http://www.greenbuildingadvisor.com/cad/detail/treated-2x4-sleepers-two-...

The GBA solution calls for treated lumber sleepers in each layer of insulation.
a) Given the high compressive strength of XPS, what purpose is served by the sleepers?

In Energy efficiency and durability | Asked By Dean McCracken | Apr 20 16
2 Answers

HRV intake below grade?

Is there any benefit to running X amount of pipe below frost grade to pre-heat/ cool intake air to an HRV? Would this not increase the operating performance of the HRV?

In Energy efficiency and durability | Asked By Kris Currie | Apr 26 16
1 Answer

What do you think about Mylar-wrapped Styrofoam board for a housewrap / thermal barrier and radiant barrier?

I would like to know if there is any reason this material might either cause a problem with the envelope or if it will be effective as and radiant barrier (both directions) or not.

In Energy efficiency and durability | Asked By Mickey Thompson | Apr 27 16
8 Answers

Closed-cell foam, unvented ceiling, and vapor barrier

This is a follow up to a previous question: http://www.greenbuildingadvisor.com/community/forum/general-questions/54...

Roof is 2:12 slope with metal standing seam over 5/8" decking. The joists ends have been blocked, sealed and wrapped.

I now have 2" of poly-iso, above roof decking, which according to this chart (http://www.weatherbondroofing.com/?page=ecomm&p=view&cid=1002&cn=XPPolyiso) gives us averaged R value of 11.4.

The overall target R value for the roof assembly is R49.

In General questions | Asked By Eric Schmidt | Mar 3 16
7 Answers

How best to insulate in DFW area (zone 3) - new construction

Hey guys,

In Energy efficiency and durability | Asked By Shawn Tucker | Apr 25 16
7 Answers

Moisture control dilemma: DIY walk-in cooler

I'm helping a great non-profit (www.nourishnc.org) create an 8'X8' DIY walk-in cooler in an unconditioned warehouse. Plans include: 2x6 construction, R23 Roxul insul, wrapping the exterior of cube in Grace Ice and Water Shield, and a really nice, donated commercial refrigerator door. Interior is FRP (fiberglass reinforced panels) glued to 1/2" OSB. Temperature of 35-40 deg F will be managed with a 12K BTU window a/c controlled by a "CoolBot". http://storeitcold.com/


In Green building techniques | Asked By Karl Kaminski | Apr 26 16
5 Answers

Is this wall assembly okay?

I live in upstate SC in climate zone 3. It would be more like 3.5 if such existed. I'm about to build a house and the wall assembly I want to use is slightly different than examples that I have seen and I'm concerned about drying/dew point.

I plan to use 2x4 wall construction, wrap it with 2" of rigid Roxul abd 1/2" Zip sheathing with a brick veneer. My thinking is I have a standard 6 9/16" window/jamb width but I have also killed the thermal bridging.

In GBA Pro help | Asked By Chip Radford | Apr 26 16
1 Answer

Hip ceiling, kneewall insulation help


First off thanks for the extremely informative site. I'm picking up lots of information, but looking for advice.

I have a 1930 Bungalow, Zone 5 (coastal Massachusetts). Vented roof with 8/12 pitch, asphalt shingles (good condition), felt and plank sheathing, 2x6 rafters.

In Energy efficiency and durability | Asked By Ryan Silva | Apr 26 16
1 Answer

How to tie exterior foundation drain to sump pump

I have already formed my basement walls for an addition to the rear of my home. I stepped down the footings to get a bit more headroom in the new basement area. Due to lot-line setbacks i poured the footers to the full extent of my dig-out and now i am running my exterior french drain around the base of the foundation wall. My only option seems to be to run the drain to day light but that requires digging a rather deep and very long trench. Is there a way to tie the french drain into a to-be-installed sump pit and pump it out.

In General questions | Asked By Mike Donohue | Apr 25 16
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