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7 Answers

Heat Pump +/- gas furnace

I am building in the mountains of western NC, Zone 4. The bid calls for a Trane 17 SEER, 9.6 HSPF two-stage, variable speed heat pump with a gas furnace backup.The house will be about 4000sf on 2 floors over a crawl, very well insulated, tight, triple pain windows with 10kW of solar. Do you think this is the correct choice for HVAC or is there something better(always considering cost, of course)? Is the gas furnace backup needed?

Asked By Kevin Spellman | Jan 17 18
3 Answers

What should I replace my heating and cooling system with?

Hi all,

I'm looking for advice on the 'best' solution to my heating and cooling (and hot water)

- Zone 5b
- Loads from coolcalc and manual D/J
Heating loads
- Main house: 28k to 36k, 900 cfm
- Sunroom addition (can be closed off): 8k, 150 cfm unducted not planning to directly heat (current situation)
- Office addition 5k/3k, 180 cfm. Unducted, can probably be heated via staircase.

- Main house cooling load: 24k to 36k, 1200 cfm
- Sunroom addition: 8k, 450 cfm unducted not planning to directly heat (current situation)

Asked By Jill D | Jan 17 18
2 Answers

Bathroom remodel, question on wall construction and shower area

Hello All,

I am currently remodeling a bathroom and need to replace my fiber glass tub and shower surround, i will be replacing it with another fiberglass/acrylic solid surface material but really had the question on how to properly build the walls in the shower area?

I will have a 2' section above and around the the shower and wasnt sure the best way or materials to do this, do i drywall with a moisture resistant product, what about vapor barrier, and air sealing?

Thanks the help and im sure there is more info needed but thought i would start here?

Thank you again

Asked By David B | Jan 18 18
14 Answers

Another try at a ceiling service cavity framing

I now want the duct ed mini split IDU(s) and ducts within the ceiling therefore what I thought was an economical construction (lattice of flat wise 2x4s) really is not, especially if I'm to have code acceptable ducts. I simply need a taller cavity, 3" isn't enough, 6" is probably minimum. My latest thought is to use a variation of a Larsen truss (2x2 chords and OSB strips on alternating sides forming the "web") installed horizontally. The "Larsen's" top chord is fastened through the upper air barrier material (probably drywall) with screws into the bottom chords of the roof trusses.

Asked By Jerry Liebler | Jan 15 18
8 Answers

Basement Insulation question


I am planning to finish my basement and need help with what materials I should use.
I live in Ohio (5A as per map). I have concrete walls with 8 ft ceiling.

I have been reading a lot and not sure what I should be using. I need good comfortable basement. I was reading best to use XPS but now after reading more I see it is not a green option. I also read there are few new products coming out with HFO blowing agents (where to buy them from or they are not available yet ?) I also looked at roxul comfortboard 80. Please advice.

Asked By bullet0770 | Jan 17 18
4 Answers

Hydronic floor heat boiler... also for domestic hot water supply?

Hi everybody! I have not been on in some time, but have received a lot of helpful information here in the past two years while renovating our home.

Asked By Benjamin Wooten | Jan 17 18
3 Answers

What's wrong with this picture (double stud wall)?

I came across this:
(which hopefully there's no rule against posting source)
apparently by BSC.

Nearer the bottom they show pictures of 'right' and 'wrong.' There is only one wrong picture... here: https://basc.pnnl.gov/system/files_force/images/ES_TESRC_4.4.4_PG102_189...

Asked By Tyler Keniston | Jan 18 18
8 Answers

Should we actively condition our unfinished basement?

We’re in SW Virginia, building a 2 story, 1900 sq ft home with a full basement. 2 inches of XPS foam under the slab, and 2 inches of polyiso on the interior of basement walls. Heat pump/forced air and woodstove will heat upper floors. Future plans include doubling the thickness of polyiso all around in the basement. Was also thinking that if we had cold floors on the first floor, I could add some insulation under the floor.

Asked By William Costello | Jan 17 18
16 Answers

Thought experiment: 30k cistern as thermal mass in passive home

Hi, we have a mountain lot in Colorado at 7500 ft elevation with lots of south facing solar heat gain, and we're planning on building a passive home. We're required to install a 30k gallon cistern for fire protection. A 30k gallon buried cistern seems to be extremely expensive, while a 30k gallon bladder type cistern is very cheap and could be installed inside the home's envelope in a crawlspace. Assuming the passive home is well balanced for on average for a year, could the huge amount of thermal mass help moderate an even temperate, or would it become a problem?

Asked By Mike AbiEzzi | Jan 9 18
4 Answers

Insulation question

Hello, The room above the garage in our house is much colder in winter (we live in Canada) and much hotter in summer than the rest of the house. We would like to insulate the space between the garage ceiling and the room's floor.

As the house 13 years old we have quite big of a space (drop ceiling ) to work with.

2 different contractors suggested different solutions:
1 - the foam spray (much more expensive option),
2- blown fiberglass.

Asked By Karina_Canada | Jan 17 18
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