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5 Answers

insulate cathedral ceiling efficiently

I just bought a house in Northern NH, zone 6 that was built in 1987. The house is about 3300sq-ft on 2 floors, so about 1600 sq-ft foot-print. The main living/top floor is entirely cathedral ceiling.

In Green building techniques | Asked By James Bodell | Dec 11 17
1 Answer

Desuperheaters in a high performance house

Does anyone know if there are any guidelines for using desuperheaters with HPWHs and ducted mini-splits in a high performance house? I will have a 65 gallon HPWH in my basement near the location for the outside AC/HP unit. There will be a 2 ton ducted mini-split HP serving the main floor, as well as a wall mount 1 ton in a loft/office area.

Does a desuperheater make sense in such a home and do mini-splits work with this?



In Mechanicals | Asked By Norman Bunn | Dec 11 17
6 Answers

Insulating Rim Joist Beyond Foundation?

Completely below grade basement in Zone 5.
Poured concrete foundation
Water barrier/proofing sprayed on foundation.
R-5 rigid foam applied to foundation (on top of water barrier)
Rim joist insulated with roughly r-7 rigid foam foil faced on both sides. Over the insulation (interior side) is a 1/2" piece of OSB. The floor joists butt into this OSB. The joints of the OSB were caulked.

In Green building techniques | Asked By BobTheWeekendWarrior | Dec 11 17
14 Answers

How to tell if I need a HRV?

So at the conclusion of my home energy audit, it was recommended that a heat recovery ventilator be installed because my house (built in 2002) is already too tight.

I always though excessive wintertime moisture was a good indication that a HRV was needed. However, the humidity level in my home drops to about 17% in the dead of winter. Isn't this an indication that I already have a ton of air infiltration?

I'm very confused and wonder if the auditor performed the blower door test incorrectly. Could the forced air system be the culprit for the dry air?

Thanks in advance!

In Energy efficiency and durability | Asked By BuildingNewb | Dec 10 17
1 Answer

Hip roof modifications

I I have just purchased a small house (20 x 24) with a hip roof in Zone 5A. The house has been extended but each (of 2) additions has its own roof. My question is about the hip roof.

In GBA Pro help | Asked By Miriam Kearney | Dec 11 17
1 Answer

additional info re hip roof question

Sorry forgot to state zone info = zone 5a

In GBA Pro help | Asked By Miriam Kearney | Dec 11 17
6 Answers

I would like opinions on my basement insulation plan

Hello all,

I plan to insulate and sort of half finish my concrete basement for use as a woodworking shop and playroom. Despite a perimeter drain and good gutters, grading etc., there is an occasional damp spot along the edge of the floor during heavy rains, but it is mostly dry.

The goal: to make the basement cozy (it's cold; I'm in Massachusetts) and avoid the telltale musty smell of the thoughtlessly finished basement. I'm a somewhat ambitious DIYer, but I am not 100 percent confident in my scheme and would appreciate feedback, especially from Martin et al.

In General questions | Asked By Alexander Lane | Dec 10 17
16 Answers

New construction: surface-mount LEDs in J-boxes or cans with retrofit modules?

I have to install 100 ceiling mount light fixtures in a new house. My electrician suggested that I consider changing from cans with LED retrofit modules to 4" junction boxes with "surface mount" LED fixtures.

This appears to be a new enough phenomenon that I am having difficulty assessing the pros and cons of these two options. Your thoughts are much appreciated.

Insulation will have some sprayfoam sections and some fiberglass.

Examples of LED fixtures that work with a J-Box:


In General questions | Asked By Bradley Lepkowski | Feb 28 16
6 Answers

Zip System vs. OSB

I am in the process of choosing between zip system and osb sheathing for the exterior of a new home project. I have read through a lot of articles on this site though I am still trying to decide on if it is worth the added cost if OSB is installed cautiously. I would still use a high quality tape on all seams. I intend to use a high quality sealant inside at the plates and blocking to sheathing joints. I also intend to install Tyvek on the exterior since the home will have vinyl siding and I don't want to rely on the tape alone at sheathing joints (if using zip).

In Energy efficiency and durability | Asked By Brian Ducharme | Dec 10 17
4 Answers

Mini split head blowing cool air

I have 4 half ton heads and a 1.5 ton head in my house that were recently just commissioned. One head seems to blow considerably cooler air than the rest. I have checked almost 100% of the lineset into the unit from the branch box and we no kinks. The branch box does recognize I have 5 heads hooked up. It did seem like it was blowing a bit warmer when it was the o my head running.

Any ideas? Thanks in advance.

In Mechanicals | Asked By Mike M | Nov 26 17
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