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3 Answers

What's the best strategy for saving energy in my unconditioned attic?

I'm in zone 5A and have 6" of insulation between the floor joists and no insulation between the roof rafters. The HVAC system and all its flex duct work are in the unconditioned attic. The building is a town house with 40" common walls running east west and the 18" roof ridge running north to south. There is eaves and ridge venting. The roof rafters are irregularly shaped: some are standard widths, others are not.

In Energy efficiency and durability | Asked By stuart brodsky | Jan 15 15
16 Answers

Mitsubishi mini split behaving very differently with external thermostat vs. without

I am able to monitor my home's electricity use and I always thought it was a little weird that my Mitsubishi FE18NA heat pump seemed to constantly be spiking up and down, considering that the whole idea of the inverter-driven compressor is that it can run smooth and steady... fast forward to yesterday when I received my MHK1 thermostat and hooked it up. Suddenly, the power usage was steady as a rock.

In Mechanicals | Asked By Nick Welch | Jan 6 15
3 Answers


MY house was built in 1896. I believe thiere is some type of wall insulation, as cold walls are not my problem. On one outside wall of my house, I can feel cold air drafts between the floor and where the wall hits the floor. It is not coming from the basment as it is cold air, and the floors in the basement along the walls have insulation. I am suspecting it is coming up under the siding and then into the house. There is a gap at the bottom of the siding where it hits the foundation. What kind of insulation can I stick up under the siding to see if this will help?

In Energy efficiency and durability | Asked By Dave Rockefeller | Jan 15 15
6 Answers

My contractor used a piece of scrap pressure-treated wood as a support to attach the new shower head to

Could the heat and moisture cause some of the chemicals to be released from the wood even though it's behind the shower enclosure? I plan on having children in the near future and safety is main issue here. Thank you.

In General questions | Asked By Suzanne Perry | Jan 15 15
7 Answers

Under Slab Foam Strength


I am in the process of getting some plans together for an addition to a 1860’s New England Colonial House that will be slab on grade construction. I have been reading about under slab foam and am wondering if anyone has been concerned about exceeding the weight load of the foam as to cause the slab to fail.

I have gotten one quote so far from a company called “Universal Foam Products” and a product called “Geofoam" that they have available in several different densities ranging from 12 to 46 PSI.

In Green building techniques | Asked By Miles Gerety | Jan 14 15
13 Answers

Drywall texture and painting

Hi all--about 70% done with our PGH and I have a drywall/painting question for the experts. Not necessarily a "green" question, but perhaps I can get a little advice.
First, we're trying to decide on the texture of our drywall--basically smooth vs. textured. The PGH will be more contemporary and it seems that smooth would be the way to go. But, at a 20-25% upgrade in price compared to orange peel. Further, the contractor recommended that, if we go with smooth, a pro painter comes in to spray it.

In General questions | Asked By Matt Mesa | Jan 14 15
1 Answer

How to optimize HVAC ducting

I will be building a new home in Idaho in an area not serviced by natural gas. Most new homes there use electric heat pumps. In brief, super insulated and well sealed 2400 SF with 900 SF attached garage, 750 SF bonus room, conditioned crawl space, vented attic. I’ve never worked with heat pumps or ducting before. I’m uncomfortable turning the design over to an HVAC contractor without specific instructions. Two have told me the air handler will be placed in the garage and return will be through the (unconditioned) attic.

In Mechanicals | Asked By Dick Lowman | Jan 14 15
12 Answers

Can I make mini splits more efficient at extreme temperatures?

I renovated a home in northern New Hampshire with meaningful air sealing and additional insulation. I installed Mitsubishi hyper heat mini splits upstairs and down, but have baseboard and wood stove backups for when the temperatures drop below 20f and the mini splits need help. Overall, I am happy.

My question is about the outdoor units. Below a certain outdoor temperature the mini splits lose some energy efficiency.

In Mechanicals | Asked By Phillip Roshak | Jan 14 15
4 Answers

Interior Basement Wall Advice

Hello all! Long time reader, first time poster.

I need some advice for insulating a full basement. Here's my situation and conditions as they currently exist. Hopefully I'm not forgetting anything.

-Location is right on the border of climate zones 4&5.
-Bare concrete block walls.
-The entire basement is below grade
-R-19 fiberglass insulation between the basement and first floor with kraft faced vapor barrier on the basement side.
-On some sections of the exterior wall, the sill plate is flush with the inside top of the wall.

In Energy efficiency and durability | Asked By Ryan Fitz | Jan 13 15
6 Answers

New cathedral ceiling with unfaced f/g batts, no air barrier or ceiling yet - planning t&g pine under...xps? below joists

Hello, all - first time post. I read all of the q&a posts I could find on cathedral ceiling insulation, and the article on how to insulate a cathedral ceiling, along with every response. So I'm informed, but still have questions about my particular situation.

In Energy efficiency and durability | Asked By Chris Johns | Jan 15 15
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