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9 Answers

Conventional heat pumps with mini-split low temp efficiency?

There seems to be quite a few options for extra high efficiency heat pumps when you go with mini-splits, but I am struggling to find conventional heat pumps that stand out. It will be connected to a standard ECM motor air handler, like a normal a/c unit would. The ducting is basically in the plans, so there is no going back now.

Asked By Mai Tai | Jun 22 18
21 Answers

Radiant Floor Cooling?

We are in climate zone 6a in a fairly dry climate. Outside humidity varies between 20% and 35% I would say on those dry days. Our home is going to of a good enough design with R-30 walls and R-60 roof with ACH50 around 1.5 and I'm unsure if I will go with triple or double glazed windows.

Asked By Steve Mackay | Apr 4 18
7 Answers

Log home heat loss

I am currently working on a project that the homeowner has asked me to help size a replacement furnace for a log home. Currently the home is heated by an outdoor woodstove, which used 15 cord last year. The outdoor stove heats water which moves to a water to air exchanger in an LP gas forced air furnace. The gas is used only as emergency heat. I'm planning on conducting a blower door test. (Last log home blower door test I conducted was 19 ACH50!) There is some roof repair that needs to be completed, should be able to figure out the R-value in the roof at that time.

Asked By Randy Williams | Jun 19 18
22 Answers

HRV / HVAC engineering help in Ontario

My building inspector came to do my HVAC rough-in inspection today. After he had ignored my e-mails and phone calls for 2 months, I gave up and just bought the Zehnder unit I wanted. The last thing he had said to me was he was "sure it would be fine", and he'd call me back in half an hour (which he never did, called him again and got another promise of a return phone call that never happened). So now he claims he sent an e-mail telling me the Zehnder didn't meet the Ontario building code, and needs a report from an engineer to allow it to pass.

Asked By Trevor Lambert | Apr 26 18
15 Answers

Do I need an HRV/ERV for a house built in 1947?

I have a three-bedroom house, one bathroom, in Worcester, Massachusetts. It was built in 1947, and measures 1,100 s.f.

After purchasing it, I decided to upgrade the insulation in the walls and in the attic and air seal the home, and install new windows. All which was done through the Mass Save program. After completing, all the energy bills went down.

But the problem now is the house has high humidity and seems to be too tight and cause hard breathing. I have noticed mold that I did not have before. Also get headaches more often than I used to.

Asked By Will82 | Jun 14 18
3 Answers

Single minisplit for AC?

Looking for feedback on adding AC to a ~1600 sq ft ranch in central NJ. Current setup is a window unit in the bedroom and a 1980s 220v beast of a wall unit in the dining room. Together they do all right in those worst weeks but for the most part we've just been toughing it out. I'm on a well shaded lot and the house stays reasonably cool during the summer, but also a bit damp. So hoping to dehumidify with the AC and of course cool the place down during the hottest weeks of the year.

Asked By Jeffesonm | Jun 20 18
5 Answers

Carbon monoxide detectors in a fuel-free house?

Just a quick sanity check here. Our house will have no fuel burning devices (also no garage), so code requires only smoke detectors, not combination detectors. Is there any reason at all to have them? The cost difference is fairly small, but if they are completely pointless then I will leave them out. Is there any other possible source of CO?

Asked By Trevor Lambert | Jun 20 18
5 Answers

HVAC duct size versus grille size

For proper air being returned to the HVAC unit that is the size of the duct have to correlate to the size of the grille for the return air? So for a 12 inch air filter grille what is the largest size return duct that could be attached to that for proper operation?

I’m getting air pressure coming from the attic through the switches ,outlets ,and around the drop ladder in a different zone than the one with what I believe is undersized return.

Thanks Rich

Asked By Richt1022 | Jun 18 18
6 Answers

Exterior vs Interior blinds

I know exterior has superior performance, but can anyone quantify how much? The latest heat wave has me lamenting the fact I didn't go with motorized, exterior blinds for the four east/west windows. Original plan was interior blinds. It's not too late to change plans, though the timeline is getting pretty tight.

Can anyone recommend a place to get these at a reasonable price? I priced them out locally last year, and they were a lot (I think four of them came close to the cost of a ductless minisplit).

Asked By Trevor Lambert | Jun 18 18
3 Answers

Replacing R410a minisplit: Lineset cleaning, pressure testing, and purging

Should I use a cleaner designed for converting from R22 to R410a linesets to clean a lineset that will only replace a R410a mini split?

I am replacing a 7.5 year old Samsung 1 ton unit with a Fijitsu 1 ton unit. These are both single units. They both require 1/4" and 3/8" lines.

I've gotten mixed answers from many HVAC professionals on this question. It seems like the wild west here in Wisconsin on mini-splits (and other HVAC subjects).

Asked By Resilient_Kevin | Jun 14 18
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