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1 Answer

Slab dimensions for passive solar

I found the following answer and need clarification on the last paragraph. When Robert Riversong says " floor area", does he mean the whole floor area of the house or just the floor that could be exposed to sunlight?

For both radiant thermal mass and passive solar thermal mass, the ideal thickness of a poured concrete slab happens to be exactly the same as the industry standard for residential applications: 4".

In Green building techniques | Asked By Christa Campbell | Feb 21 12
7 Answers

Is this truss lift??


The link is to images of this case. Click the "show info" upper right of slide show for captions.

This production house in S.E. Pa. has a trussed roof. It is 3 years old. The first season (October) a drywall joint opened up (1/4" +/-) at the change of ceiling plane in the picture where the flat ceiling meets the "cathedral" ceiling. The builder installed a foux beam over that area to conceal what they thought would be a seasonal event. Now the next joint over opens up seasonally.

In GBA Pro help | Asked By Robert Post S.E. Pennsylvania Zone 4a | Feb 20 12
2 Answers

A Simple Building Energy Index

Here goes a late night post, but this has been bothering me. One of the big issues with PassivHaus seems to be the way energy usage is measured.

1. The building measurement side is strange since interior partition walls don't count as floorspace and basement floorspace is multiplied by 0.8 (if I understand everything correctly).

2. The somewhat arbitrary space heating energy usage limitation designed around German conditions, which have apparently been modified by the Swedes and Austrians to match their more severe climates, becomes a problem in other areas.

In Energy efficiency and durability | Asked By Karl Overn | Feb 19 12
3 Answers

Crawl Space and Insulation

My sister lives in Alabama in a house that is a couple hundred years old and it sits appox. four feet off the ground. The problem is - she has no insulation in her her floors and won't put any in because she was told that she would have a mold problem.

I thought that plastic on the ground and attached to the walls would keep out the moisture. But someone has her that you must leave holes in the plastic to let the moisture escape. Isn't that wrong? What's the best way?

In Energy efficiency and durability | Asked By William Wingett | Feb 19 12
7 Answers

How long will paint or stain last on a vented siding assembly?

I'm wondering if anyone out there can give me some more direction on how many years I can expect to go before needing to repaint the siding on our new house (when there's a vented siding assembly involved?)

Our plan is to install clapboard siding over 3/4" strapping. We are trying to decide between fiber cement clapboard siding and cedar clapboards. Painting is high on our list of least-favorite-ways-to-spend our summer, but I much prefer the look of real wood to fiber cement.

In Energy efficiency and durability | Asked By heidi davis | Feb 17 12
2 Answers

Any logical reason for a register in unconditioned attic?

I was helping a friend move seasonal items into the unconditional attic of a rental house she is moving into (zone 5a), I was shocked to see a register in the floor of the attic. The heat was turned down and I am not certain if if was a heat vent or cold air return, but is there any reason for either to be in a unconditioned attic?

In Mechanicals | Asked By J. Gaub | Feb 18 12
8 Answers

Replacing oil fired to natural gas

I currently have hydronic heat via oli fired boiler to basboards (single zone to two floors). Contemplating converting to natural gas and splitting zones via hot water coils to existing central air system. There is an air handler in the basement and another in the attic. The question is...is it more efficient to remain with a single zone via baseboards or split the zones via existing ducting?

In Energy efficiency and durability | Asked By Jeff Mark | Feb 18 12
1 Answer

Best work-around for oversized HVAC?

My house has a 5 ton AC which was oversized for the house even before weatherization. However, the unit is only 5 years old and I don't want to replace it yet. Below are some suggestions to get the unit to run longer to increase efficiency and moisture removal.

In Energy efficiency and durability | Asked By Dorothy Prowell | Feb 18 12
2 Answers

Ventilation and Radon Mitigation

Hello all-

My home is in climate zone 5a. We recently had a radon mitigation system installed due to elevated radon levels. It is a sub-slab depressurization system and is working very well.

However I have a couple of questions:

1) If I want to improve ventilation in the house (separate and apart from the radon issue), can I install an HRV or ERV or will this affect the effectiveness of the radon mitigation system? Said differently, what would be the best type of ventilation solution that would improve air quality and even help further reduce radon levels?

In Energy efficiency and durability | Asked By Allan Wood | Feb 17 12
6 Answers

Damaged earthen floor -- repair or replace?

Hello all-
I had an earthen floor installed in the cellar during a renovation/rehab of a multi-family townhouse. The major components of the earth floor (substrate, vapor barrier, tamped earth, etc.) were completed many months ago but the tamped earth was not sealed and finished.

In Green building techniques | Asked By Jennifer Shaffer | Feb 17 12
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