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49 Answers

I have been reflecting on heat pumps in general lately

After reading "Solar thermal is really, really dead," which produced quite a reaction, is it possible that heat pumps themselves are at least wounded?

PV at $3.50 watt installed... Note that heat pumps are still great for all places where PV is impossible.

In Energy efficiency and durability | Asked By ven sonata | Feb 4 15
26 Answers

Most cost-effective whole house ventilation solution for Massachusetts?

I am building a Tier III home on Cape Ann and will be having a single minisplit heat source for my open kitchen/living/loft area with 2 bedrooms and a bathroom also downstairs (896 sf downstairs). I have read all the discussions regarding exhaust only ventilation vs HRV/ERV. There are many HRV systems out there at varing costs. I am trying to find the most decent cost effective solution to whole house ventilation. I was considering Lunos fans but have heard that white noise could be an issue. I am looking for quiet and also cost effective to run over time as well.

In Mechanicals | Asked By Victoria Williams | Feb 19 15
6 Answers

Are 1 heat pump with 3 multiple indoor unit Hyper Heat minisplits available from Mitsubishi yet?

I have a really simple question. I have installed a ductless mini split in my studio, but have been waiting for Hyper Heat units that can handle multiple zones to be on the market (1 heat pump w/ 3 indoor units) to be on the market to put them in my home. Mitsubishi website seems like they're out now. Anyone know for sure?

In General questions | Asked By DANIEL GOTTSEGEN | Feb 20 15
5 Answers

Any idea how to fix this?

I was digging the flower beds and discovered this in the fall. The original dirt level was about to the asphalt shingle shown. I have no idea why its there but from the inside of the house i have some pics in the wall where theres the same type of asphalt in the foundation or just above it, it was hard to get a pic but if anyone is interested i can dig it up.

A few weeks later when there was heavy rain water was coming in at a good clip as you can see in the basement pic, i suspect its coming in under the mudsill and through some plaster (parging?) before the dirt trails shown.

In General questions | Asked By Alan B | Feb 21 15
11 Answers

Will a minisplit with an air handler be adequate for Zone 7A?

I am building new construction with SIP walls in NW Wisconsin zone 7A. House will be 2000 sq.ft. single level with an insulated basement. I am interested in heating with a Mitsubishi minisplit using an air handler to distribute air throughout the house in a ducted ductless mode as seen on Ask This Old House feb19, 2015. The handler has backup elec. resistance heat for a heat boost when needed. Three basic questions.1 Will this be adequate to heat this house? 2. Can the air handler be mounted in the basement to distribute air and can we avoid having the units typically mounted on walls 3.

In Energy efficiency and durability | Asked By terrance kaase | Feb 19 15
3 Answers

Insulating outside wall against moisture

I have an outside wall with soil piled up due to grading against a wall. I heard installing an "insulation curb" would help. What kind of people should I hire to re-work it and install "installation curb"?

In Building Code Questions | Asked By Anthony Ng | Feb 18 15
4 Answers

Heating/Cooling Degree Days

John Straube, in his book "High Performance Enclosures", indicates that for Heating Degree Days, in a high performance home, a base of 50 degrees (i.e. HDD50) should be used for computing annual energy use for heating. That reduces my average annual HDD65 of 4365 to HDD50 of 1838 in Louisville, KY.
Is there an equivalent high performance home base for Cooling Degree Days ?
Do you concur with Straube's assessment ?

In General questions | Asked By Ted Cummings | Feb 20 15
2 Answers

Cathedral ceiling efficiency retrofit

I live in NH (zone 5). I am trying to make some efficiency improvements to a roughly 14ft by 20ft room with a cathedral ceiling that is 14ft at the apex. The room connects the main house and the garage. There is one skylight in the ceiling and two light fixtures. There are no canned lights. The room is on its own heating zone (oil). The room has never been very warm, and like most 1986 built houses, it was not built with an eye towards efficiency. The walls are 2x6 and are insulated with standard fiberglass batts. The 2x10 ceiling is also insulated with fiberglass batts.

In Energy efficiency and durability | Asked By Michael Lee | Feb 20 15
5 Answers

BIBS fiberglass dense pack vs. cellulose dense pack

After reading about all I could find on dense pack fiberglass vs cellulose (which is much less then I'd have expected)...I decided I'd love to have cellulose in our new +- 3000sf home/shop that is being built in Western SD...BUT...I cannot find any professionals to install it.

We have taped the seams of the osb and brought the air seal across the ceiling. We are installing a HRV. Lets call it zone 6b

In Energy efficiency and durability | Asked By daryl stisser | Feb 18 15
17 Answers

Cold living room floor

So, like many people, I have a cold living room floor above my garage. I have begun to pinpoint several areas of major air leakage to address (thanks to renting a thermal camera from Home Depot). One major issue that I discovered (and already suspected) was that the garage ceiling has very poor insulation. I have a second story bay window cantilevered above the garage door (garage townhome). This past summer I had to have the bottom paneling replaced due to wood rot.

In Energy efficiency and durability | Asked By Neil Lambrecht | Feb 16 15
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