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5 Answers

I am in zone 5A and I have a problem of excess humidity in my ICF home with no abnormal sources of moisture (5 occupants of a 2150 sft home with a full basement). This results in condensation on the wall of windows facing a pond on the north.

Since a dehumidifier will also dump heat into the home helping my all-electric furnace heat the home, I am wondering if it would cheaper to run the dehumidifier than to use an ERV to lessen the humidity in the home. I realize in the latter case, there's some loss of sensible heat that the electric furnace would then have to compensate for.

TIA.

In Energy efficiency and durability | Asked By Venkat Y | Aug 29 14
1 Answer

So based on everything thing I am reading should we be using R3 R4 or R5 for each inch of Polyiso since it decreases in performance as it gets colder. I seem to be seeing some variation in Answers. I am in zone 5 and was planning on putting 5 inches of Polyiso.(thinking that was R 30 Roughly but if is is only R 15 when coldest that is a problem) Now it seems like I would be better served with three inches of polyiso with EPS on top. I have access to 1.5 or 2.75 inch EPS. Would I still be OK with 3 inches of polyiso and 2.75 inch of EPS on top?

In Energy efficiency and durability | Asked By terry grube | Aug 29 14
Answers

Hi Folks,

I am advising on a home renovation in Sudbury, MA. It has become obvious that the structure -- about 20 years old -- was built without thought to airsealing. The resulting home performance problems are likely predictable to GBA readers.

Now, the owners are turning a 3-season sun room into a 4-season room and need help figuring out how to best heat and cool the new space. This project also presents an opportunity to address other related issues.

In Energy efficiency and durability | Asked By c talwalkar | Aug 30 14
3 Answers

My new house is designed to limit penetrations through the building envelope to as few as possible. Nevertheless, sillcocks, outside electrical receptacles, outside lights, HRV intake/ exhaust, etc. need to be sealed.
Are there methods or products that are more effective than others? How about ease of installation? I've seen photos of tape covering holes and that seems like a pretty clunky solution. I'm probably going to either do much of the airsealing myself, or at least supervise it.
Thanks for any advice.

In Energy efficiency and durability | Asked By stephen sheehy | Aug 29 14
4 Answers

I keep hearing the term "acoustical sealant" in the context of air sealing, as in "use acoustical sealant for air sealing because it remains flexible", but am a little bit confused as to what it means. Does it refer to:

  1. Tremco accoustical sealant, the specific product?
  2. Any caulk or other sealant that exhibits the "remains flexible forever" property?
  3. Something else entirely?
In Green products and materials | Asked By Aaron Birkland | Aug 29 14
1 Answer

I understand from prior posts there are concerns with the flash foam and fiberglass insulation in terms of moisture vapor.

Would the use of proper barriers and Roxul instead of fiberglass help to abate that concern?

In Energy efficiency and durability | Asked By George Levicki | Aug 29 14
5 Answers

I am in the final phase of completing my first PERSIST remodel.
We have installed (2) layers of reclaimed 2" polyiso on the walls (over TYVEK drainwrap) of a 1940's ranch and then strapped with 1x4's using headlock screws. Existing walls were in decent shape in terms of flatness and corners were within an 1/4" of plumb over 10'. So the walls were not perfect but they were pretty good, not bad enough to catch the eye.

In General questions | Asked By Charles Chiampou | Aug 24 14
3 Answers

Here are the facts about this house first;

In Energy efficiency and durability | Asked By Richard Beyer | Aug 29 14
20 Answers

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
15 Answers

I would like to ask the math pros here on how to calculate heat loss from infiltration rates.

I have seen so many different formulas in the last weeks that my head is hurting.

So would like to have a "reliable" formula that could be used in my never-ending expanding excel spreadsheets !

Something with at least a little bit of proven precision, that could be used to effectively get additional heat loss using door blower results or planned target value.

Links or straight formula please :)

In General questions | Asked By Jin Kazama | Aug 25 14
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