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4 Answers

Envelope air tightness sanity check

Designing a "Contemorary Industrial Passiv Ranch Haus" for DIY build in SW Colorado (CZ6B). Working through data entry in PHPP now and I know the one level elongated ranch style is sub-optimal for PH design. It's 2250 ft^2 (OD) with conc. slab and shed roof. Floor/ceiling/wall envelope area is 6982 ft^2 and volume is about 25789 ft^3. An optimal PH two level cube would have envelope area of 4531 ft^2 and volume about 19125 ft^3. I'm over that by 154% and 135% respectively.

In PassivHaus | Asked By Chuck Jensen | Feb 15 14
0 Answers

Follow-up on reinsulating attic floor

Back in 2010 I wrote in and received some good guidance from " Riversong. " We were considering reinsulating the attic floor. As a follow-up i thought that I would report the results. We had an insulation company remove the fiberglass from the attic floor and fill the cavities with Demilec Agribalance open-cell foam. In the main area of the floor the 2" X 6' cavities are filled and then covered with 7/16 osb. The " outer " areas without flooring have up to 9 or 10 inches of foam. They installed baffles to protect the soffit openings.

In General questions | Asked By Russell Namie | Feb 16 14
2 Answers

I wish to insulate the external walls of a Victorian house

The current hardboard siding is due for replacement and I'm considering fiber cement. What's my best, most cost effective insulation option to achieve R-6?

I'm concerned that relying on an external insulation of 1-1.5 inches will compromise/ strain the cladding.

In Energy efficiency and durability | Asked By raj mathews | Feb 15 14
1 Answer

A mix of building science, advanced products & FREE BEER!

Announcing PHnw 5!

The Northwest best mixture of building science presentations mixed with advanced product vendors in ventilation, windows, air barriers, water restive barriers, co2 heat pumps and all of the latest gadgetry to produce any type of low energy building enclosure: PH, NZE, LBC PGH.

Thursday March 29th: Advanced Classes (limited seating) https://www.phnw.org/100/32/phnw-5-pre-conference.html (class info coming soon)

In PassivHaus | Asked By albert rooks | Feb 15 14
8 Answers

Moisture between underlayment, plywood, and metal roof

We're building a sunroom addition, nuts to do this in winter, especially this winter in the Atlanta area, but so it is. I'm doing a lot of the work myself, help from a metal roofer with other skills. This contractor wasn't finished framing a 1.5/12 shed roof dying into a 5/12 roof, waiting to sort out a particular issue, but went on to place 1/2 plywood, Rhino underlayment, then 24 gauge 1.5" standing mechanical seam metal roof panels. The underlayment running out the top runs a couple feet, was tucked under asphalt shingles from garage roof, a couple screws thrown in to keep it down.

In General questions | Asked By Benjamin von Cramon | Feb 13 14
17 Answers

Best minisplit system in Zone 6A for a 2-story home?

Experts, Dana and all...

I propose best system might be

1 outside unit hyperheat etc... I only know what you all post...
2 indoor heads that are large enough to one at a time heat the home from 1st floor
and cool the home from 2nd floor most of the time with worst case scenarios taken care by the fact
that there is a "reserve" head.

Question... can this system be built and installed for$5-10,000 and will it be as efficient as 1 head designed to 1 outside unit?

In Energy efficiency and durability | Asked By aj builder, Upstate NY Zone 6a | Feb 10 14
4 Answers

What is the minimum width of residential steps?

First of all, I have a guide book to the code but not the actual code book. I have read the section on egress over and over, I have looked for answers on the net and as you can imagine it is up to how someone interprets the code. There is a lot on handdrail but nothing that says stair treads have to be a min. of 36" which is what half of the people seem to think. The only reference to 36" that I have seen is for above the handrail. That is not an issue for me. I need to know if I have treads between the timber stringers, can they be 32"? I need to do a 4 step landing at bottom turned 90 degs.

In Building Code Questions | Asked By John H. Stehman | Feb 14 14
2 Answers

Which minisplit to get?

I'm new to this site and have been reading a lot of info on minisplits. Could anyone tell me which size Mitsubishi FHxxNA series or Fujitsu model I should get for my house: a 24,000 sf split-level home in Zone 7. The cold weather gets to -30F or so in Dec. and Jan., so it would need to be the better heat-efficient one.

I have a Pacific Energy wood stove; here is the TECHNICAL INFORMATION for the wood stove:

Heat Output Cord Wood (BTU): 72,000 BTU
Heat Output EPA (BTU): 36,600 BTU
Efficiency: 81.6%
Emissions: 3.4 gm/hr
Firebox Size: 2.1 cu.ft.
Log Size (recommended): 18 in.

In GBA Pro help | Asked By Perry Comeau | Feb 13 14
6 Answers

Why are refrigerator coils not mounted outside of our homes?

Wouldn't it be more efficient to exhaust hot air outside in summer like an air conditioner? And in winter why isn't cold air from the outside used to maintain fridge and freezer temperatures? Thanks!

In General questions | Asked By Jane McClintock | Feb 13 14
9 Answers

Modified flash-and-batt

Is it reasonable to do a combination of closed-cell spray foam in the unfinished attic rafters and batts on the ceiling flats?

Reasoning for this is to (a) get HVAC in the attic within the envelope where rafters can't be properly vented, and (b) still have insulation on top of the flat ceiling drywall because there is some ceiling-radiant heat. And there's the added benefit of getting some of the R value from a cheaper product.

Does the R38 code requirement allow the insulation to be in two different places as long as it totals the appropriate R-value?

In Energy efficiency and durability | Asked By Dave Frank | Jan 22 14
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