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0 Answers

Air exchange / ventilation / dehumidifier options for a sealed, 640 s.f. structure

I am building a 640 s.f. structure and insulating i twith closed cell spray foam. Heat is provided by a fireplace with an outside air supply and baseboard heat.

I need an energy-efficient air conditioning / ventilation / dehmidifier / air exchange solution, mainly to keep it dry, but also to keep it cool.

It is located in a typical, four season climate where we get hot, humid summers and cold, snowy winters.

Asked By Nathan Hiscock | Feb 8 16
15 Answers

Geothermal and SDHV in new ICF home

We are in the process of building a new home in Climate Zone 5. It is an ICF [insulated concrete form] construction from basement foundation to gable.

I am intending to use a SDHV [small duct, high velocity] system for forced air and heating in conjunction with a closed loop ground source heat pump.

What I am trying to understand is the impact to efficiency caused by my desire for SDHV on the heat pump options side of life.

Asked By Esteban Carlos | Feb 4 16
6 Answers

Will this exterior wall system work for my tiny house?

I live in South Dakota in zone 6a (Sioux Falls). In a few months time I will be constructing a tiny house on wheels using 18 gauge structural studs. Starting in the wall cavity will be sprayed closed cell foam. On the exterior sides of the studs (and any other exposed metal areas- the steel trailer) I plan on using strips of 1 inch thick xps rigid foam with a compressive strength of 60 lbs/square inch. Also I will use steel strapping all around the outside to give it some shear strength and prevent racking.

Asked By Damon Beck | Feb 7 16
0 Answers

Using a second water heater as an indirect fired tank?

I have two water heaters. A 50 gallon HTP Phoenix Light Duty propane water heater, and a 50 gallon electric resistance water heater. The two heaters are plumbed in series, electric water heater first, then propane. To make a long story short, some things didn't work out as originally planned, and now I'm paying an extra $15-20/month (and wasting source energy) because I'm heating up a bunch of water with electric resistance right next to a high efficiency propane water heater.

I'd like to stop doing that. I have a couple of extra constraints:

Asked By Tim C | Feb 8 16
9 Answers

Best insulation for indoor air quality?

I cannot decide on a type of insulation for our new home. I want something that is the safest for indoor air quality. I am worried about the off gassing of spray foam, but am also worried about the borate used in blown in cellulose (mainly the reproductive effects of borate). Please help! I want energy efficiency, but indoor air quality is of primary concern. Thank you!

Asked By Carolyn Farrow | Feb 8 16
2 Answers

Basement remodel / Subfloor questions

I have a few questions about my plan to insulate a subfloor in the basement.

Let me provided the pertinent details and my purposed plan.

The brick ranch house located in zone 4a (Virginia) was built in 1965. It has both an above and below grade basement. The structure is concrete block. The front long wall and one short wall are completely below grade. The back wall and half of the other side wall are above grade. The basement is conditioned.

Asked By Steve Basic | Feb 3 16
1 Answer

Shingle roof over closed-cell foamed rafters

Martin - I'm the architect for a new house. The roof will be:

Wood shingles over
Horizontal strapping over
Vertical strapping over
Grace Ice and watershield over
Plywood sheathing over
Closed cell foam

Do you recommend this? Will there be trouble within the sheathing 'cause it's trapped between two non-breathing membranes: Grace Ice and Watershield (top) and closed cell foam (below)

Many thanks,

Louis Mackall
(you may remember me from Trident launchings in Groton!!)

Asked By Louis Mackall | Feb 8 16
6 Answers

Raised-heel trusses can be annoying

We installed raised-heel trusses with bottom chord overhangs on our house. The top of the top chord is 20" above our top plate. According to the 2012 International Residential Code for seismic zones or zones designated for winds of 100 mph, raised heel trusses more than 15.25" have to be blocked and braced.

Asked By Jimmy Nguyen | Feb 6 16
24 Answers

Best way to fix insulation problem in cathedral ceiling? Please help!

I built my chalet about 8 yrs ago and was up in the attic and noticed black water stains (probably mold).
after many days and night researching what was wrong, i believe my issue is insulation and air leakage.
i have called all the insulation and roofing businesses (not many in this area) and each says its the others issue.

this site has been the most informative, but i cant seem to find any article or videos on how to add or change insulation in a cathedral ceiling after construction has been done.

Asked By Aaron H | Jan 31 16
0 Answers

Proper DHP sizing

So, I ran a Manual J calculation for a number of Portland, OR apartment units I'm renovating (2bdrm/1ba, ~750sqft each). All fall in the 12.5k-13.5kbtu range for heat load; closer to 9-11.5k for cooling loads depending on orientation. When I click over to the Manual S sizing calculator, it mentions Emergency loads of 10k minimum - 18k maximum. I'm not sure what exactly this means, and how it should affect sizing choice. Calc outputs are attached for reference.

Asked By jonathan nagar | Feb 8 16
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