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15 Answers

Is this a reasonable solar bid? — and other questions

Howdy folks,
I got my first solar bid today, from Consolidated Solar Technologies. For a 3.2 kW ground-mount array in Albuquerque, New Mexico, the total cost before the federal tax credit is $16,300, and $11,410 after the credit. This works out to $3.56/watt.

One thing I worry about is that their calculator shows a higher projected output than PVWatts does. Their tool showed 6,500 kWh yearly, but PVWatts shows 5,844 kWh. This is supposed to be a net-zero-enabling array, so I don't want to underproduce. I'm using 6,500 kWh for my yearly usage

Asked By Nate G | Dec 5 16
2 Answers

Converting a 1830 House to a Super Insulated House

I am diving into the insulation in my 1830 Farm House, 1500 sqft, which is located in upstate NY. I am looking to retro the house into a tightly insulated house that will ultimately heat off of electric heat or heat pump mini splits. I just had 10kw Solar system to create the electricity for the heat. The solar system was designed to cover 110% of our projected electrical consumption with a mini split system running. My goal is an 1830 super insulated house.

Asked By Larry Broderick | Dec 7 16
2 Answers

Insulation options to add R-value

I had the opportunity to reroof this spring and add exterior rigid foam. I used foil faced polyiso 2.75" thick. Due to time and money constraints I applied a single layer taped and foamed. Through fastened wth .5" OSB cut into 3" strips. A new OSB deck was installed and asphalt shingle roof on top of that.

Asked By David Mosijchuk | Nov 23 16
3 Answers

Batt insulation

I'm in the process of buying a home (Metro New Orleans, Zone 2A, very warm and moist) for my daughter and noticed the attic insulation was installed with the Kraft paper facing up. That problem is being corrected by the seller, but now I wonder if the wall insulation was installed incorrectly as well. When given an opportunity to re-inspect this coming Monday I will be removing electrical covers and other things to see if the insulation problem continues with the outside or exterior walls.

Asked By Bill Stretzinger | Dec 6 16
9 Answers

Can this assembly work for a flat unvented wood roof in Atlanta, GA (Zone 3)?

Hi all, I am building a flat un-vented wood roof in Atlanta, Ga (Zone 3) and I want to make sure I am doing it correctly. The assembly that I have so far is:

-TPO roofing
- 1/4" exterior grade drywall cover board
- 2.5" Tapered insulation
- 4" Rigid tapered Insulation
- 2" Rigid Insulation
- Waterproof Coating on osb / or peel and stick waterproof membrane
- 5/8" osb
- 2x10" beams (all at the same height)
- 2" closed cell spray on foam insulation
- 1 layer 5/8" type x Drywall
- Resilient channels
- 1 more layer 5/8" type x drywall

Asked By A Patel | Dec 6 16
6 Answers

Exterior foam application and window details

Im in Phoenix about 6 months away from starting my build. I was thinking about upgrading my exterior foam from 1.5" to 3" EPS. The window detailing is where my question lies. I've read the articles here, but we will be using mostly EFIS for our exterior cladding (with some stone veneer). My thought was to nail the window to the exterior after the OSB and Tyvek stucco wrap just like you would without using foam. Then add the 3" of EPS right up to the edge of the window and just add the EFIS to the 3" return created. For the stone veneer we will just frame out the window the 3 inches.

Asked By Jeffrey Savage | Dec 6 16
5 Answers

Interior walls acting like exterior walls

New construction in zone 5. We have 3 interior walls that we have to build up still where the vaulted ceiling meets the flat(see pic). We are planning unvented on the vaulted side (3" closed cell, and fill the rest with cellulose, but just blown in cellulose on the flat ceilings. How would you recommend I build and insulate this wall? I figure I need to treat it like an exterior wall, so drywall, studs filled with fluffy and 3" of rigid foam?(that is what we are doing for our other exterior walls). Thank you in advance.

Asked By Michael Brackett | Nov 29 16
6 Answers

What is the relationship between air source heat pump and indoor heat pump water heater?

I am sure this has been analyzed here before, but I want to check my reasoning. A criticism of heat pump water heaters is that they cannibalize the home heat source and so during the heating season perform exactly as electric water heater efficiency. However if the heat is provided at COP 3 from an external air source mini split, then am I correct that the heat that is being "borrowed" by the heat pump water heater is also COP 3 and so year round the heat pump water heater functions at COP 3 or better?

Asked By ven sonata | Dec 5 16
3 Answers

Insulated impact-resistant windows

I have a house in Florida (climate zone 2a) with windows facing west. We replaced all windows and sliding doors with white aluminum frame impact rated, insulated, low e glass with grey tint. The specifics on the windows are: Insulated, large missile, Low-E = Windoor GR2, grey tint, 3/4"
NFRC ratings: U factor =0.61, CR = 16, SHGC = 0.23, VT = 0.29

Asked By Pamela Greacen | Dec 6 16
11 Answers

Minisplit questions

-I'm in zone 4, midwest US, and am about to buy a ductless split system for my main structure and the addition I'm finishing now. I am concerned as three of the five rooms I am putting them in are pretty oversized (~2600k btu load cooling, using the 6k heads) and the rep is saying I should go with the H2i. He said if I never need the low temp operations, the heater was worth the money.

Asked By Mike M | Dec 5 16
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