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10 Answers

Adding rigid insulation?

Hi, I've been reading through information for a few days now, and am honestly more confused now than when I started. I'm sure this question has been asked before but I couldn't find anything specific to my area(zone). Here is my situation... Thanks in advance for all replies.

In Energy efficiency and durability | Asked By Mike Watts | Jul 16 15
6 Answers

Moisture concerns with double stud in 4a?

Hi all,

First off, this is a great website! I have been reading all that I can on super-insulated homes and this site has been a huge help.

In Energy efficiency and durability | Asked By Clay Whitenack | Jul 17 15
3 Answers

Flashing 120-year-old windows to new ZIP R-sheathing

I am slowly retrofitting an 120 y/o home in climate zone 1. As typical with homes of this vintage it was very leaky, both of air and occasionally wind blown water during hurricanes. We had to remove most of the siding on one of the walls and are building it back with ZIP R-sheathing and rainscreen siding.

In Green building techniques | Asked By MIke Truxillo | Jul 17 15
25 Answers

What's the range of window air leakage values for good-quality US windows vs. garden-variety vs. Passive House-quality?

It's very hard to find published window air leakage rates (in cfm/ft2), harder still to get independent test reports with this information. So far I've found the following data points:
* a maximum of 0.3 for all of one US mfr's product line (in an internal manual);
* .02 for a tilt-turn unit by same mfr (from independent test report);
* .003 for a Canadian mfr's tilt-turn unit (from website literature).

I've also been told that the test apparatus doesn't yield a result smaller than .01.

In Green products and materials | Asked By Ann Edminster | Sep 19 09
2 Answers

Looking for a ductless air conditioning unit with a low indoor temperature setting

Looking for a ductless air conditioning unit with a low indoor temperature setting. Just had a Mitsubishi guy out, and their lowest setting is 67 degrees, which isn't low enough for sleeping. My window unit goes to 60 and I usually set it at 62 but my room is still a few degrees warmer.

I've been in hotels where the air goes only to 67 and it's uncomfortable.


In General questions | Asked By Liz Cullen | Jul 16 15
21 Answers

Community insights for a straw & steel green build?

We are building a straw-bale house with steel bones in Sacramento, CA in spring 2015 and I'd love to get some insights from the community! We are pretty far along into the design process, but with nothing purchased as of yet I'd love to get some input before we put our money where our mouths are.

Our goal is to have a (mostly) passively heated and cooled home in (relativity) temperate Sacramento, CA. Passivhaus would be nice but it's an aspiration rather than a goal. Our lot has a number of trees for shade that we plan to utilize, especially in the western aspect.

In Plans Review | Asked By Nick Campbell | Aug 26 14
3 Answers

Closed-cell spray foam vs. high density batts

We're currently in the planning/permitting phases of a new home in the Southeast. We've hired a green building specialist to give us some specific recommendations and model our home to give us an approximate hers rating. He has advised that we use high density fiberglass batts in our mostly cathederalized ceilings upstairs. Our contractor (traditional) has recommended closed cell spray foam because he thinks it will help with the structure and have less air permeability. There's a definite cost difference. Please help steer us in the right direction.

In Energy efficiency and durability | Asked By Megan Wood | Jul 11 15
7 Answers

Interior T&G pine with rigid foam exterior insulation

Hi all,

In Energy efficiency and durability | Asked By Adam Emter | Jun 9 15
5 Answers

Are airtight homes causing indoor air quality problems?

In the quest to conserve energy by making the homes so air tight the quality of the air inside the home has gotten worse.

In General questions | Asked By Jack Lofstrom | Jul 15 15
16 Answers

Slag & fly ash geopolymer?

The father of geo polymers, Joseph Davidovits, has proposed a standard geo-polymer cement that uses fly ash, blast furnace slag and a "user friendly" alkali activator to make a cement. It' sets at room temperature in several hours and develops outstanding strength quickly.(7000+PSI @ 28 days). Without additional aggregates it is about 2.8/ inch. Since it uses about 90% waste materials it is quite "green". With that kind of insulating structural concrete far less plastic foam would be needed, a typical basement floor would be r10 by itself.

In Green building techniques | Asked By Jerry Liebler | Mar 16 15
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