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8 Answers

Options for hydronic air handler control: properly coordinate ECM blower motor and variable-speed condenser compressor


First post. Not sure if this is best in Mechanicals or Energy Efficiency. Please move as you see fit.

High level: Replacing condenser unit and air conditioner coil. Since the work is being done, now is the time to upgrade the air handler mechanicals and controls as well. I need help understanding options for properly coordinating an ECM infinitely variable blower motor with a multi-stage/variable speed condenser compressor. And this needs to work with my hydronic heat too (currently air, but will be adding radiant at some point).

Asked By D D | Aug 10 16
4 Answers

Forced air heat register location

My heating contractor wants to put the heat registers along the outside wall, near windows, the traditional way of doing things. My thought was to minimize ducts and the associated losses and keep them centrally located, with at least one in each room. With all the talk here of using centrally located minisplits and that working out OK, I don't see why I need heat regs along the outside wall. I can see it being a little better, but not necessary in a house with pretty good windows, air tightness, and insulation. You don't need passive house levels to pull this off do you?

Asked By Brad H | Aug 5 16
3 Answers

Thermal break wall hydrant?

Dos anyone make a fiberglass, or other non thermal conducting material, freeze proof wall hydrant?

Asked By Calum Wilde | Aug 5 16
9 Answers

Conflicting information

I have had 2 insulation contractors review a rehab I am working on. It's a small cape, 2nd floor, it has been gutted. There is an existing ridge vent and gable end vents, minimal soffit venting. Walls are the slope of the roof.
Both are saying dense pack cellulose. One says install proper vents "rafter vents" the other says no venting is required. One will spray floor to peak, the other floor to flat part of ceiling, and fill above.

Who is right, do I install proper vents and open up soffit vents??
or just sprayy floor to peak and close up vents??


Asked By David Brown | Aug 3 16
4 Answers

Good source for minisplit turndown ratios and turndown vs. HSPF / SEER?


I was going to ask this on this thread:

But realized it was a separate question.

Asked By Keith H | Jul 28 16
11 Answers

ERV + dehumidifier ducting in a minisplit house

I'm working on a 2400sf house (CZ4, but very nearly 3) where the owners have selected minisplits - one ductless 1st floor, one ducted w/ very short runs for each of 2nd & 3rd. So there will be no major duct lines throughout the house for heatning and AC. They've also chosen to go the ERV and Dehumidifier route, this being the humid southeast.

Asked By Chris B | Jul 28 16
3 Answers

ERV as a bathroom vent fan?

My wife and I are purchasing a new house. House is in NJ and was built in 1987. Stick framing, average to slightly above average construction quality, average energy efficiency as far as we can tell.

For whatever reason, none of the bathrooms have vent fans. Putting fans in is likely to be one of the first projects I do.

Simple question - is an ERV appropriate to use as bathroom ventilation in a not-so-tight house? Our priorities are as follows:

#1 remove moisture to reduce mirror steaming and mold potential
#2 energy efficiency in terms of not wasting heated/cooled air

Asked By Matt Culik | Jul 28 16
5 Answers

Reducing humidity without AC

I live in NJ. Typical summer weather here is highs in the mid-80s/low-90s, lows in the 70s, and very humid.

Our house has a "natural" overnight temperature of about 73. What I mean by this is that if I set the AC to 74 before we go to bed, it cycles on/off until about 3AM, at which point everything has cooled off enough outside that no more AC is required to hold 74.

While this is nice from an electricity use perspective, no AC means the interior air gets stuffy and the humidity starts to creep up.

What is the most energy efficient way to address this?

Asked By Matt Culik | Jul 28 16
9 Answers

How should I heat my water?

Hi there. I'm just starting a major renovation of a two story studio space attached to our detached garage to be used as a studio and sometimes guest house. We're adding water and septic to the house, and I'm looking for ideas on the best way to get hot water. We'll only have a single bathroom with shower, and a small wet bar sink on the same wall as the bathroom, so there are no long pipe runs. Usage will be infrequent but once in a while fairly aggressive if we have guests there who need to take multiple back-to-back showers.

Asked By Curtis M | Jul 17 16
7 Answers

Solar Water Behind a Window

First a quick back story: I live in Halifax, Nova Scotia, which to my knowledge is zone 5...? I'm getting condensation on my cold water pipes, where the pipes first enter my house from my well. In another question about this issue, Charlie Sullivan was kind enough to offer a suggestion of using a drain water heat recovery unit to preheat the cold water. Which, really is a great suggestion as it's 100% passive.

Asked By Calum Wilde | Jul 21 16
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