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7 Answers

Second guessing ERV/HRV install

Planning for new construction in the Finger lakes region this year. Both our architect (recommends ERV) and a local insulation contractor (recommends HRV) are advising us to install a stand alone ventilation system as we will not have an HVAC/duct work. After reading some of the articles on this site; I'm not sure how necessary it is to take on that expense.

Asked By Nina in CNY | Mar 26 17
3 Answers

What experience has anyone had with MLI (Multi Layered Insulation) in attics?

Specific product by Yellow Blue. Also their solar fan for attics

Asked By DaveDish | Mar 30 17
12 Answers

Green & Passive design

As an architectural designer, I have long been interested in green and passive home design, having dabbled and dreamed. I now have a project that will encompass both, as well as the use of SIPs for roof and walls.
Simple questions with elusive answers:
1. Where can I find the angles of the sun at June 21 & Dec. 21 for a specific latitude?
2. How do a loft area and high vaulted ceilings fit in? It seems that both the Window to Wall ratios, and mechanical load numbers are all calculated using square footage. Surely ceiling height and volume have an impact.

Asked By Becky Nemetchek | Mar 29 17
8 Answers

Need sizing advice on a minisplit unit

I installed a Mitsubishi FH12NA in summer of 2014 when they first came out. I live in inland San Diego, and it can get hot, like 10-15 degrees hotter than the coast.

My condo is a studio and is only 420 sq ft. I'm on the upper unit of 2 stories. I face East and South. I have a skylight and dual-pane windows. Building is 1978 construction.

My Mitsubishi is weak. I set the temp and it will barely do anything. I have to set the temp to 61 and manually put the fan on high for it to do anything. Even "powerful" mode is weak.

Asked By aypues | Mar 16 17
5 Answers

Rim joist with exterior EPS

My home has 1" of EPS on the exterior walls and covering the rim joist. The rim joists are uninsulated on the inside. If there was no exterior rigid I'd use a combo of rigid foam board and batts on this inside, but because of the exterior insulation, I'm concerned about creating a vapour sandwich.

Is the best approach here to air seal from the inside with caulk or canned foam, then add FG or roxul batts to allow inward drying?


Asked By ryan ryan | Mar 29 17
7 Answers

Floor above unconditioned space

Firstly thanks for the feedback on my previous roof assembly post. This question relates to the floor of the conditioned area (ceiling of a garage/carport). Thankfully no ducts, just wires and plumbing in a few locations.
By way of background, its climate 4C (near Vancouver, Canada) and a small building used as a holiday home, not fully occupied in Winter. The occupied conditioned space will sit above both an unconditioned garage and cantilevered over a carport.
Designers build up from conditioned side down:
- ¾ OSB T&G
- Poly sheet
- 9.5” I Joists on 16” centers

Asked By Quinn Sievewright | Mar 29 17
0 Answers

what to choose between Sun-Tek ISFG 2549 skylights or Kennedy 4622ISFG skylight for the tile roof

Roofer was supposed to put Kennedy 4622 ISFG skylight but brought in Sun-Tek ISFG 2549. Is one way better than other or we will be fine with the either one of them.

Asked By vileparle_2 | Mar 30 17
2 Answers

How durable is practical for a conventional light-framed house?

This question comes from Calgary, Alberta, which is (barely) in climate zone 7B. For those who are unfamiliar, Calgary would have a fairly extreme continental climate but for the periodic Chinook (foehn) winds that frequently raise wintertime temperatures by 30 or 40 degrees Fahrenheit. (This both to pretty extreme freezing and thawing cycles and to a climate that is, at times, somewhat more extreme than its number of HDDs would suggest.)

Asked By WantsToBuildGreen | Mar 30 17
11 Answers

Critique this rough floorplan

We are in beginning stages of choosing an architect/project manager, but we have some wishes on how we want the floor plan to be.

Being amateurs, I'm sure there are mistakes. Please critique.

Our goals, wants and needs:

- make the house as small as possible, ut with enough room for everything we need/want
For example, we want a study, though that is not common practice here. We took that good practice from USA and like it a lot.

Asked By davor radman | Mar 28 17
5 Answers

Energy-efficient envelope advice

I'm building a high efficient cabin in climate 6 (dry) and have got a ton of helpful info from this site. I was hoping the the experts that frequent the site could make comments or give advice to improve the design. Also, let me know if there is something that doesn't mesh with the current building science. Any input would be helpful, thanks.

Foundation System:
Sealed crawl space with vapor barrier and 4” rigid foam insulating interior foundation walls.
Ground Floor System:
I joists with R30 batt insulation.
Above Grade Walls:

Asked By David Voros | Mar 29 17
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