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6 Answers
Question about the Panasonic spot ERV

I work for a non-profit organization weatherizing homes. I live in the deep South, so ERVs provide good potential benefits in this region.

We've recently installed two of these units but were disappointed in the cfm reading we got. the unit is advertised at 40 cfm, however using the flow pan and manometer the highest reading I could get on this unit was around 11 CFM.

In Energy efficiency and durability | Asked By jamar lambert | May 6 13
10 Answers
Conversion of delivered energy to primary energy

I am looking for the factor that allows me to convert delivered energy (electricity in kWh) to the primary energy.(kWh) value. Location is British Columbia where most of the electricity generated is hydropower if this would have an impact on the ratio of primary energy to delivered energy. Many thanks.

In PassivHaus | Asked By Manfred Winter | Apr 30 13
1 Answer
I would like to insulate the attic rafters but I would like to keep the rafters visible for a decorative look

Are insulation boards available with a wood look to them? I saw something on the internet that had that look but have not been able to find what i saw

In Energy efficiency and durability | Asked By jorge romero | May 4 13
1 Answer
Question RE: Installing polyiso around a stovepipe

I am doing a weatherization project on my house where I am installing polyisocyanurate below the ceiling rafters. I have an existing stove pipe and chimney in place for the fireplace that came with the house. I want to get rid of the fireplace and install a wood stove. The existing stovepipe/chimney are double walled and I think the interior pipe is 6" (not sure) and the exterior is 10" or 12" (unsure on that too).

What specials precautions must I take to install the polyiso around the stovepipe?

The polyiso is 14 feet above where the top of the stove would be.

In General questions | Asked By Kevin Lauscher | May 4 13
4 Answers
Where to place snow guards?

Part of my retrofit included a standing-seam metal roof, the type
with snap-together panels. I've read some of the folks' prior
experiences with metal roofs and snow, and spent some of my first
winter watching the big cornices slowly form over the edge and
then thud down -- in the back of the house, onto the basement
bulkhead and outer edge of the little matching rooflet over the
heat pump [and boy, am I glad I constructed *that* to be strong],
and shoveled most of what fell farther away from the house so it
wouldn't form a huge mound and then melt toward the basement wall

In Green building techniques | Asked By Hobbit _ | May 2 13
2 Answers
Help me determine my wall's dew point

I’ve spent hours researching this site (which is great by the way) to try and determine what the dew point would be in a proposed wall assembly-(flash and fill). I’ve read the blog mentioning Joe Lstiburek’s approach which seems to be based more so off a wall system with exterior insulation board. I also found a table stating in need 2” of closed cell insul. So I’m a little confused.

In General questions | Asked By v a | May 2 13
20 Answers
R-value vs. thermal mass

Hi GBA,

In GBA Pro help | Asked By David Epley | Jan 26 12
8 Answers
SIP home with 2 air handlers for open space floor plan?

Plans / pics are attached

Exterior walls are SIPs R-24 with 1-1/2" EPS stucco
Center 'bumpout" is typical 6-9 stick with 3" EPS (interior to be sprayed)

WIndows are Integrity Low E3

window wall south facing

Proper way to heat and cool

We are in the process of building a very open floor plan home with catheral ceilings in CT (zone 5) with 2 levels.

Main level - 9-17' ceilling heights
Lower Level ( Walkout) has radiant in an exposed slab and footings over 2"EPS.

In Mechanicals | Asked By Chris van Wilgen | Feb 5 13
1 Answer
What is the best way to plaster an exterior wall insulated with straw bales?

We are wondering if it is wise to plaster directly on the 2" mortar that protects the straw bales or if we should use furring and plywood on which we would fix a screen to put the plaster on. It would add an air gap between so that the wall could dry better but we don't know if it is worth it.

What do the experts think?

In Green building techniques | Asked By Serge Bedard | May 1 13
1 Answer
Link to Building America study on exterior insulation retrofits

Here is a link to a recently published Building America study on several exterior insulation retrofit projects:
Project Overcoat — An Exploration of Exterior Insulation Strategies for 1½-Story Roof Applications in Cold Climates

In Green building techniques | Asked By j chesnut | May 1 13
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