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5 Answers

Recommendations for Manual J software?

Hi All,

I'm looking into software to perform Manual J calcs, and perhaps also do other simulation/calculations as well. I'm fluent with the PHPP and another software called TrnSys (from a previous job), but I'm looking for something more common in the residential efficiency world.

In Mechanicals | Asked By Cramer Silkworth | Jan 10 12
3 Answers

Sealing Brick Veneer...or not?

I have a modular masonry fireplace. The chimney has a brick veneer with a small gap between the brick and the masonry blocks. I initially had a small leak through the brick and onto the chimney's built-in brick ledge (in the attic) during a rain. This seems to have stopped based on observation during subsequent rains. It has been recommended that I spray the chimney brick with a sealer.

1) Do I need to do this? Why did it leak at first and now it doesn't? The mortar wasn't fully cured at the time of the initial leakage---would that make a difference?

In General questions | Asked By john walls | Apr 22 12
3 Answers

Installation of finless windows

I will be buying windows for a new construction. The difference in cost between windows with nailing fins and those without is $1000 for the package. This is significant money and I would like to take advantage of it unless there is a compelling reason not to. If the reason comes down to ease of installation I can deal with that. What are the other benefits of fins over non-fins?

In Green building techniques | Asked By Ben Raterman | Apr 18 12
6 Answers

1.5-inch-thick polyisocyanurate insulation on cinderblock walls

I am working on a cinderblock house (every forth cell is solid) with plaster interior finish applied directly to the cinderblock. We are replacing windows, doors, and siding and the idea is to fur out the cinderblock and place polyiso insulation between the furring strips, then .5 inch OSB over the Furring and insulation, then house wrap/stucco wrap, and stucco part of the house and wood clad other sections of the house.

In General questions | Asked By John Placek | Apr 17 12
2 Answers

Hawaii construction: doors, windows and the elements

I've worked in design & construction for decades now, but am faced with a challenge to design & build a house in a very windy, salty, sunny, termite infested location in Hawaii (and yes, subject to earthquakes, but only 110 mph winds).

In Green products and materials | Asked By d t | Apr 20 12
7 Answers

Insulation and barriers on inside of a double brick wall

I am in Toronto Canada doing reno work and have stripped the walls in a few rooms down to the (double layer) brick wall. I am puzzling over what air and moisture barriers combined with insulation would be best. I don't want to loose too much space. 2X4 wall thickness or possibly up to 2x6.
Can I have foam sprayed directly on inside of brick ?
Or, more conventional , a layer of tar paper nailed to brick(or should I fur this first?), then a wood framed wall insulated insulated.

In General questions | Asked By Richard Clark | Apr 5 12
1 Answer

Staggered studs on 2x8 plates....anyone do it?

There is a lot of talk here about OVE framing, double stud wall framing and various types of thick exterior foam options. However I have not found much talk at all about staggered 2x4s on 2x8 plates. I realize this does not eliminate thermal bridging at the sills and heads of the walls, but I would have to assume it would create a slightly stiffer wall too. 2 rows of 2x4s cost about the same as a single 2x8 around here. The 2x4s would be on 12" staggers, so a 24" o.c. on their respective sides.

In General questions | Asked By Jesse Lizer | Apr 23 12
3 Answers

Two-story home on slab vs. one-story with basement


I'm looking at building a Passive House (or close to it) in Pennsylvania. My kids are teens, so I had considered building a 1-story home and put the kids' bedrooms in a finished basement. I had also considered a boxy 2-story on a slab.

Both arrangements have their pros and cons in terms to materials required (the cost of basement walls vs. more framing/siding/windows, etc.). I don't think a lack of daylighting will be an issue since my kids are only in their rooms to sleep. Anyone have an opinion on the matter?

Thanks in advance!


In PassivHaus | Asked By Jason Kibbe | Apr 16 12
1 Answer

Air sealing effects

I have a very leaky home and am contemplating having air sealing done as well as some improvements to the insulation. While I know this will help improve energy efficiency, I was wondering a couple of things:

1) Once the air sealing is complete and the house is tighter, will indoor air quality be affected? That is, less air exchanges with the outside. If so, should I look at installing mechanical ventilation (i.e. HRV, ERV)?

In Energy efficiency and durability | Asked By Ellyn Daniel | Apr 17 12
7 Answers

Insulation for vehicles - if not Reflectix, then what?

Much thanks to everyone here for the great comments on Reflectix on the other Q&As. I'm glad I read them before I bought any!

But now I am stumped. This is one of the main recommendations on the RV-builder forums for insulating a vehicle to avoid condensation and keep warm/cool.

I am preparing a Chevy Express cargo van for research work (using it as office/sleeping area). It has a steel skin, and hollow steel "studs" spaced about 2 feet apart, about 3" deep between. Ceiling is similar. Also, there are voids in those "studs" and in the door recesses. (http://bit.ly/HRnArM for a pic).

In Green products and materials | Asked By Dylan Gordon | Apr 17 12
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