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13 Answers

Is there a "direct vent" clothes dryer or kitchen hood?

It seems to me we focus on creating super tight envelopes and then cut holes in it to purposely blow out an enormous amount of air with clothers dryers and kitchen hoods. We either create negative pressure in the home or bring in unconditioned air with make up dampers. HRV's and ERV's now solve that issue with bath fans, but isn't there anything out there for dryers and hoods? My thought is there should be some kind of venting system like the direct vent on the back of a fireplace where the incoming air gets conditioned by the outgoing air.

In Green building techniques | Asked By Andrew Homoly | Oct 6 11
3 Answers

Is there much of a difference between .27 and .22 in the solar heat gain in new windows for Fort Worth, TX?

We are purchasing new windows for our home in Ft. Worth, TX and want to know if it is worth spending an extra $20 to $30 per window to improve our solar heat gain rating from .27/.28 to .21/.22.

In Energy efficiency and durability | Asked By Craig Schaefer | Mar 9 12
4 Answers

Moisture barrier & insulation for barn loft

I have a 30 x 40 two story barn that the upstairs loft had been insulated with fiberglass batts and drywalled for a temporary residence. The floor of the loft is 2x8 rough cut joists 16" center with 5/8 plywood flooring. It had been insulated from below with fiberglass batts that has been damaged by birds and rodents. The loft is now used for storage and I plan a workshop area that would only occasionally be space heated for short periods of time, so I can't justify putting a huge amount of money into insulation.

In Energy efficiency and durability | Asked By J. Gaub | Mar 9 12
8 Answers

Spray foam and batt insulation combination

We are renovating our 2nd floor bedrooms due to moisture problems and are seeking the most efficient and cost effective means to insulate. We live in the lower thumb area of Michigan and the the rooms have 2x6 cathedral ceilings. The previous method used was 6" R-19 kraft faced batts with durovent baffles(improperly installed/long story), with soffet and ridge vents. I do not wish to add to the 2x6's and shrink the rooms so I need to maximize the use of the 2x6's. I would like to use 2-3" of closed-cell spf and fill the rest with either 3.5" r-15 batts or 2.5" rigid foam board.

In Energy efficiency and durability | Asked By Jim Rogers | Mar 6 12
37 Answers

Night-time setback w/ radiant floor

I was talking to a heating contractor about a radiant floor system, and we don't agree regarding night-time setback. I'd appreciate some light shed on this.

The system has a typical slab on grade with R-10 under it and PEX tubing cast in, and another area of framed floor with PEX underneath with aluminum distribution plates. The boiler is a 30kw electric with multiple elements and outdoor reset.

In Mechanicals | Asked By David Meiland | Feb 10 12
2 Answers

Is it OK to mulch Zip Wall and Zip Roofing Material?

I am building a LEED Platinum home and plan to convert all my scrap lumber to mulch. I used the Huber Zip Wall and Roof Panel system and have scrap material with the green and red coatings of these products. I know from the LEED for Home Reference Manual that it is OK to mulch OSB and plywood. Does anyone know if the "kraft paper" coating on the Zip panels is OK as well? I called the technical department at Huber and they don't know either. They sent me the MSDS sheets, but they don't know if it is considered acceptable to use as mulch.

In Green products and materials | Asked By Andrew Homoly | Mar 8 12
1 Answer

Raised heel on a standard sawn stick?

So it's a 12 pitch roof with a full dormer. Can we build up a regular sawn stick, (2X10) to make more room for insulation above the wall? I recently saw....(guru, here) saying that we ought to have at least as much insulation above the wall as is in it. The plan is for a 12 inch wall, It is the dormer rafter that I am getting at. Could we make a birds mouth by adding material, rather than the usual removal? Like someone might make nasty to a stringer.
Whattaya think?

In Green building techniques | Asked By dave litwak | Mar 8 12
15 Answers

Make-Up Air Heaters to Balance a Range Hood

I'll be breaking ground this Fall for a new home in Maine that will be small (1,214 sq ft) and super-insulated. Heatload requirements are estimated to be around 9,100 Btu/h in the dead of a Maine winter to keep the place at around 72F. One challenge I'm facing is maintaining the thermal efficiency of the home when using a gas range top and ventilation hood on a regular basis.

In Mechanicals | Asked By Litawyn Eco-Cottage | Feb 3 12
1 Answer

Clear skies tonight?

Good night for viewing the aurora even at lower latitudes (peak viewing between 1 and 5am EST):

The video embedded is worth watching despite the commercial.
It's a bit mind boggling to imagine how powerful the forces involved in a solar flare are.

This story reminded me of Martin's Halloween blog.

In General questions | Asked By Lucas Durand - 7A | Mar 7 12
22 Answers

Best wall construction for long term efficiency & durability: Zone 6A

First off, thank you GBA for creating this fantastic resource for all to use. My wife and I built our current home 5 years ago and we were considered cutting edge for our area with the first home to use SIPs (PU 4") and a Superior Walls Basement. Now we are looking to build a new home for our growing family and move even further north in Michigan (Zone 6A per your map) so we were hoping for even better insulation in our new home. We currently have R24 walls and R60 attic with energy heel trusses.

In General questions | Asked By Paul Shank | Mar 5 12
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