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10 Answers

Ultimate Air vs. Zehnder HRV

I recall seeing in the comments for the article discussing a new way to duct hrv's that one of the Zehnder reps was disparaging the Stirling Technologies Recoupaerator 200dx for having something to the effect of misleading, incorrect, etc. performance numbers and that it does not stack up to Zehnders products. I was wondering if that rep and anyone else could clarify why the Zehnder product would be better than the 200dx and how they differ in function? The cost of the 200dx is significantly less.

In Mechanicals | Asked By Spencer Burnfield | Sep 4 12
6 Answers

Installing 2 Vinyl windows with no nail flange in a 6" opening depth

I'm turning our sunroom into a finished space. The current slider windows are 2 be replaced by 2 vinyl single hung units (73" x 52"); each unit has a 2 single hungs and a vinyl joint between each to make it a solid unit.

The current sill is sloped 2x8. Based on my recommendations and manufactures install is to shim sill at 24" and jambs at 16" (only fastening the jambs).

They say if > 65" wide consider fastening through the still; but from the advice I've been given from contractor and rona is to not fasten on the sill as it could compromise drainage.

In General questions | Asked By Mike Tew | Sep 20 12
3 Answers

Hardwood installation

How does one correct for the the common area (hard wood) not being straight during installation now that I'm installing hard wood into the corresponding bedrooms?

In General questions | Asked By kevin haag | Sep 20 12
1 Answer

Substrate options for earthen plaster on interior over cellulose

I am building a home in coastal BC and discovered clay under our plentiful sand. It would be great to use this for an earthen plaster on the interior of our house. Currently, the plan is a staggered 2x4 stud wall on a 9.25" plate blown with cellulose. The exterior will have plywood, Typar, 2" rigid insulation such as Roxul ComfortBoard IS strapped (perhaps with pipe or wood squash blocks or just extra thick strapping direct on plywood and Roxul cut to fit between), so that there is a rain screen gap, then fiber cement siding.

In Green building techniques | Asked By Patrick Walshe | Sep 21 12
11 Answers

Fastening methods for Roxul ComfortBoard IS

I was wondering if anyone has field tested Albert Rooks' suggestion of using full thread (or broken thread) screws to get consistent screw compression on the strapping and prevent wavy siding. That sounds way simpler than cutting holes in Roxul / inserting sections of plastic pipe. One builder did not know about these options and ripped all the roxul off a side due to this issue. His Comfort Board was 1.5 inches thick I believe. I would like to put untreated strapping over 2" comfort board then fiber cement siding.

In Green products and materials | Asked By Patrick Walshe | Sep 17 12
7 Answers

Dew point in deep cavity walls & Spray Cellulose

Home located in central mountains of Idaho @ 5,000 ft elevation.

To curb possible condensation problems & air-seal In a double-stud wall cavity, I was planning on spraying 2lb closed cell foam 3.5" thick then spraying remaining 6.5" of cavity with cellulose for a total r-value of around 44.

In General questions | Asked By Eric Mikkelsen | Sep 20 12
6 Answers

Is recycling 30 year old plywood a good thing?

On my gut rehab and second story addition in New Jersey, I'm considering recycling the plywood from the roof. Is this a good idea?

In General questions | Asked By Michael Arnold | Sep 19 12
7 Answers

Polyiso under slab between 2 polyethylene layers?

I have seen posts for and against Poly ISO under slab and want to get some feedback on a alt design technique.

Our project, is a monolithic slab pour with radiant, single story, with a walkout lower level. We would like to maintain the exposed concrete floors. Located in CT zone 5

Under slab options- confusion -

I am reading that the 6-15 mill poly barrier should be BELOW the 4" of compacted stone so that the water in the concrete can dissipate and cure faster, makes sense.

In Green building techniques | Asked By Chris van Wilgen | Sep 19 12
3 Answers

Offered free equipment — Is it a good deal or not?

We are building a near passive house in Upstate NY. For the HVAC system the goal is to get both heating and air conditioning in at least two zones (three is better: living area, master suite, and second floor (offices and guest room)) with a wood stove as backup heat plus an HRV. We've been offered an opportunity to get equipment and some installation cost for a system from GTI(Gas Technology Institute)/NYSERDA (New York State Energy Research & Development Authority) that combines a solar thermal system with an air handler which they will compare to a system without the solar thermal.

In Mechanicals | Asked By Elizabeth Kormos | Sep 19 12
4 Answers

Does the fresh air have to go directly to bedrooms in an HRV retrofit?

When specifying requirements for the mechanical ventilation system in a new home, we typically ask for exhaust points out of bathrooms and kitchen (and sometimes mechanical room) and we call for fresh air points in living spaces and each bedroom.

In Mechanicals | Asked By Rachel Wagner | Sep 19 12
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