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4 Answers

Basement ceiling insulation required by code — but what about the basement door and stairwell?

Seems like a huge thermal hole in the basement ceiling. Code requires R30 in zones 4 plus for unconditioned basements. What about the bottom of the stairs (to 2nd floor) and exposed stairwell walls? People typically just use an interior door to the basement, right?

In Building Code Questions | Asked By Dwight Harris | Oct 15 14
3 Answers

Unusual thermal envelope intrusion at roof-penthouse

Hi,

I've discovered that the ~1987 penthouse addition to my house is partially outside the roof thermal envelope . Since it is attached (naturally) to the remainder of the house it compromises the performance of the whole house.

In a nutshell:

In Energy efficiency and durability | Asked By Keith H | Oct 14 14
27 Answers

My husband and I want to build an efficient house

My husband and I want to build an efficient house. The only problem is we are on a very tight budget.

In General questions | Asked By K Nuss | Oct 11 14
10 Answers

Choose between more/better insulation, or heat pump?...

Last year we had an energy assessment performed in our 1880's home and were recommended several options. We opted to first pursue air sealing in attic with 20" of blown in cellulose. This made quite a difference both in comfort and heating bills.

Our remaining recommendations:

1 - Insulate walls with dense pack blown in cellulose.
2 - Insulate crawlspace (closed cell spray foam).
3 - Replace 4 windows original to house (drafty!!)
4 - Install high efficiency air source heat pump.

In Energy efficiency and durability | Asked By Christian Rodriguez | Oct 9 14
4 Answers

Sizing a minisplit for a 900-square-foot Chicago carriage house

I have a two-level carriage house (900 sq. ft. total). Brick structure, framed in with R-19 insulation, two levels, open loft style.

I'm wondering if the 12000 BTUH Mitsubishi MZ-FE12NA would be enough to heat the space, or should I go with the 18000 BTUH MZ-FE18NA?

Also, is there any reason why I should consider the Fujitsu minisplit too? I've had good experience with the Fujitsus in a warmer climate (than Chicago), but the specs on the Mitsubishi Hyper Heats seem hard to match in a Fujitsu.

In Mechanicals | Asked By timothy flynn | Oct 15 14
6 Answers

Insulating an attic furnace room

I have a furnace in my attic around which the builder constructed an enclosure from 2X4 and foil-backed fiberglass insulation. I've been told the R-value of the insulation should be sufficient, but there is clearly air getting through at the seams and creating hot spots in the attic which then leads to ice dams etc. What is proper protocol for insulating these attic "furnace rooms"?

In General questions | Asked By Patrick Finn | Oct 15 14
3 Answers

Vapor barrier

So where do you apply the termite treatment when placing on com. site?

It only make sense to get your sub grade, apply your termite treatment, then your vapor, then your gab, then your steel/wire, then your concrete.

Anything else would put your vapor at risk of being damaged, right?

That's with 4 inch and 4 inch concrete.

In General questions | Asked By mike brackett | Oct 15 14
1 Answer

Thoughts of REMOTE style building in eastern Canada

Dreaming of building a home aprox. 26x30 two story facing towards south with two large triple glaze casement windows (5'x5') per floor, my thoughts are to use REMOTE on a slab with 4" of exterior foam (eps) and blow in or roxul with in the stud cavities (2x6). The main reason, I am wishing to use REMOTE is for airtightness, plus the thoughts of having less wetting on the sheathing. Am I barking up the wrong tree? The home with be built in Charlottetown, PE.
I know this is very basic info, wishing to heat with minisplit.
Thanks Marty

In Energy efficiency and durability | Asked By marty nichol | Oct 15 14
5 Answers

Islandable battery bank box venting options

Anyone out there have experience with battery bank ventilation in a tight house?

We're building a PGH in Climate Zone 4A. It's designed for net-zero, so we'll have a 6 kW grid-tied PV system. It will also have islanding capability (provided by a dedicated inverter and 12 kVA battery bank).

Based on a rough blower door test we are < 0.6 ACH50.

The battery bank will sit in the basement, which is conditioned space. I want to make sure we are venting the battery box in a safe and effective manner. As I see the issue:

It must vent hydrogen gas effectively
It must not backdraft

In Mechanicals | Asked By Daniel Ernst | Oct 12 14
13 Answers

Space and water heating for a micro-load house

I've been re-reading Martin Holladay's posts on water heating as I once again deal with a small-ish super-efficient house: 1900 ft2 with a heating load of less than 20 kBtu/hour. The homeowners have access to propane and electricity and here in MN, electricity is still generated by a lot of coal, although the homeowners are planning for a pv system.

At the moment I've narrowed heat/hot water system ideas down to three:
1. use a 6kW modulating electric boiler for space heat (hydronic radiant) and also to fire to an indirect tank for hot water. Also, use a drainwater heat recovery device.

In Mechanicals | Asked By Rachel Wagner | May 14 13
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