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5 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
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
10 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

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
1 Answer

Good advice for Florida homeowners with air conditioner problems

Curt Kinder is an HVAC contractor who understands building science principles -- and that type of HVAC contractor is, unfortunately, rare. Curt lives in Jacksonville, Florida, and he often posts comments on GBA.

Curt is helping to raise the bar on building science knowledge in his profession. He was recently interviewed by public radio station WJCT. If you want to hear some of his advice to Florida homeowners -- it's good advice -- visit this web site: Going Green.

Asked By Martin Holladay | Jun 15 18
1 Answer

Flood protection bags for HVAC equipment

I saw these on the RDI site. It sits under your furnace or hot water heater and rolls up in case of flooding to protect the equipment. Anyone used one?

Asked By Scott Wilson | Jun 11 18
6 Answers

Mitsubishi multi-zoned system for passive house too much?

I'm building a 4 bedroom passive house with about 3,200 sqft of conditioned space including a home office and a 2 car garage and 1 car garage (workshop) totaling around 800sqft. I would like to use an 8 zone mitsubishi system with horizontal ducted indoor units. Zones will be assigned to each bedroom (zones 1-4), the home office (zone 5), the main living area (zone 6), the 2 car garage (zone 7), and the worshop (zone 8).

I have a few questions:

Asked By Mike AbiEzzi | Jun 9 18
5 Answers

Whole-house fan, residential economizer, or low ambient kit?

I'm on the southern edge of Zone 5A. As I am nearing the point where I will start construction, I'm working with a contractor and subcontractors on some of the details.

Asked By User-7027358 | Jun 8 18
11 Answers

Flex duct material for ventilation system

It was recommended to me by a couple of independent sources to include a short run of flex duct between my HRV and the supply and return manifolds, for noise control purposes. The idea is to decouple the unit from the ducting as a means of reducing vibration transmission. I've looked at several options:
1. Vinyl dryer duct. Very flimsy, has a pretty nasty smell to it, probably not a good choice from an air quality standpoint.
2. Foil dryer duct. Also very flimsy.
3. Semi-rigid aluminum dryer duct. Seems too rigid to actually achieve the goal of decoupling.

Asked By User-6792900 | Apr 11 18
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