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9 Answers

Dryer vent in air-tight Passive House

I am building a house in the Seattle area to Passive House standards. After spending countless hours sealing every crack, seam and penetration to achieve under 0.6 ACH, creating a 4 inch diameter hole in my air barrier pains me. I've looked into condensing dryers that are used in some European Passive Houses, but they seam to take much longer to dry and use lots of water. Since I will be installing a vented dryer (unless someone can come up with another solution), are there ways to make the dryer wall vent more air-tight when the dryer is not in use?

In PassivHaus | Asked By Gerald Blycker | Nov 21 14
3 Answers

Manual J - Calcs - Mini Splits

Zone 4B - 3,300 sqft - 2 story - R10/R25/R60 with R8 windows - open floor plan design

The calcs came in at 3.25 tons heating/cooling. Two ductless minis per floor:
3 - 9,000 Btu Mitsubishi Hyper Heat Pumps - 26 SEER - 10.5 HSPF
1 - 12,000 Btu Mitsubishi Hyper Heat Pump - 26 SEER 10.5 HSPF

$12,000 installed (P&L) for all units - 10 year warranty

In Mechanicals | Asked By Peter L | Mar 26 15
7 Answers

Evaluating feasibility of solar panels in site rated at 895 (or 65% TSRF)

Just got a quote from solar panel install company and thinking I may skip solar and redirect funds to doing more insulation work on the house. But before I do that, I wanted to run some thoughts by here.

1. I am calculating that per kW I will be at $4.25 installed (I am in Boston area). Considering article I just saw today on GBA pegging average installed price $0.80 less per kW I am discouraged.

In Energy efficiency and durability | Asked By Apollo S | Mar 25 15
6 Answers

Strapping material for rainscreen...plywood fir or spruce?

I'm ready to put the strapping on-top of my WRB, only I'm not sure what the best choice is.

I want a 3/8" gap, so cutting plywood strips is my only option (there is NO composite furring strips available in town...I called everywhere!)

I've got the option of 3/8 spruce with exterior glue, or 3/8 fur with exterior glue.

Does either have a lower tannin content that may deteriorate the WRB? Do I even have to worry about that? Should I back prime the strapping to avoid this?

I'm going to put cement board over the strapping then stone.

Thanks!

In General questions | Asked By Mark Helmrich | Mar 16 15
26 Answers

Structural Insulated Panel (SIP) roof decay

I have a BensonWood timber frame in Vt that is only 8 years old with significant panel roof decay. So much so that my standing-seam metal roof has begun to rust from the inside out. There is evidence of SIP seam failure in several places below the standing-seam metal roof. Is it likely this was the cause? It is a hot roof.

In General questions | Asked By gregory raith | Oct 3 11
6 Answers

Suggestions/advice on vapor barrier product to use?

In the basement of my house (built in 1900) in NE Ohio...Half of the basement floor is finished, the other half is dirt floor covered by a few inches of crushed stone gravel. I had a mold issue, so looking to put a vapor barrier over the gravel floor. Also am getting slightly elevated radon level about about 4.9 to 5.1. I'm hoping maybe to solve both issue with one fix. Here's my dilema...I'm looking for a vapor barrier material that would withstand occassionally walking across it.

In General questions | Asked By Justin Stine | Mar 25 15
1 Answer

Improving panned return ducts

Our bungalow is a standard setup, with a 2 story addition added later. In the whole house, best I can tell, there are 3 return ducts, all on outside walls of the original house (1 is now interior), all on the 1st floor and all panned. I can access some of them from the basement.

The 2 farthest from the furnace are panned across to the center of the house, then in a duct going below the joists, then back into a panned duct that goes above the duct pushing air out, and then into another duct that goes back to the furnace, if that makes sense.

In Energy efficiency and durability | Asked By Jeremy M | Mar 25 15
9 Answers

Modular house design overview

Hi All,

My presentation can be found at https://www.scribd.com/doc/258417069/House-Design-Overview-R3?secret_pas...

I am going to build a new house this year in south eastern MA. To reduce construction time I am planning on going with a modular builder. To control costs I am acting as the GC and planning on doing the HVAC install, attic and basement insulation, and plumbing/wiring hookups. I am still looking into modular builders, hopefully I can find one who is willing to set the house and make it weather tight and allow me to finish the rest of the work.

In GBA Pro help | Asked By mike haskell | Mar 11 15
2 Answers

Where is the building envelope?

Doing several additions with new gable roofs overlaying the existing roof. New and existing roofs will have foam the underside of the roof sheathing. The question centers on where the envelope should be on the triangular overlay portion of the new/old roofs and should that triangle be vented in anyway.
Thanks

In GBA Pro help | Asked By Robert Brown | Mar 24 15
12 Answers

Cool roof on a rigid foam retrofit

Hello,

I have been doing extensive research prior to begining my remodel on my new home. I would like to get some advice on how to aproach my remodel.

The home is a 2600 sq ft contemporary style house. The majoroty of the roof is an unvented catherdral roof assembly. It is a simpole gable roof, although the North face is much steeper. It currently has an aging asphalt roof that will need replacing soon. I am planning a PV array instalation and need advice on what sort of assembly would be the best combination.

In Green building techniques | Asked By David Mosijchuk | Mar 23 15
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