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39 Answers

Best way to ventilate a garage?

I am converting my 2-car garage (432 sq. feet) into a combo exercise space / 1-car garage. I recently discovered that it had a mold issue, and had it remediated. The Indoor Environmental Professional (IEP) that I worked with suggested installing an ERV in the garage to ventilate it and also put it under supply pressure, which he said would make the mold issue less likely to recur. (If the ERV doesn't keep the relative humidity low enough, he also suggested a portable dehumidifier.)

In General questions | Asked By Chris | Dec 18 15
1 Answer

Rain leaks on sunporch

Water sometimes runs down the side jambs on two of our three west-facing sunporch storm windows. Lately it seems to be happening with every rain instead of infrequently. The gutters are clear and are draining properly. The water comes in around where the venetian blinds attach (see second photo).

During the summer, I tried spraying the windows with a garden hose, but no water leaked in. Maybe I didn't spray long enough?

I'm thinking of running a bead of caulk above the drip cap on the vinyl siding (third photo). Any downside to that? Any other suggestions? Thanks in advance.


In General questions | Asked By Jonathan Beers | Dec 27 15
4 Answers

Low EMF electric stoves, water heaters, and dryers?

Trying to find low EMF dryer, stove, and hot water heater. Is there a difference or are they all close to the same? Thanks, ben

In General questions | Asked By Ben | Dec 25 15
9 Answers

Passivhaus Builder certification and BPI Building Analyst certification


I am at the beginning stages of getting my Class A Builder's License in Virginia. Apart from that whole process of getting a contractor's license, I was wondering if getting certified as a Passivhaus Builder or BPI Building Analyst is beneficial not only for expanding my knowledge and creativity, but also from an economic and networking standpoint. Has anyone received new clients or jobs from being listed as Passivhaus or BPI certified? Has anyone gotten hired to a great new job from being certified?

In PassivHaus | Asked By Jimmy Nguyen | Dec 1 15
56 Answers

Why must HVAC decisions be so complex? (Or... Is geothermal worth it?)

In another thread, my choice for HVAC was appropriately questioned. The system seems inordinately complex, costly, and convoluted. At least, on the surface. But digging deeper, the reasoning behind the design becomes clear. But, does that make it right? Is this the best HVAC design, or is it redundant and wasteful?

Here are the pertinents:
• Climate Zone 6
• 2700 sq. ft. finished space in story-and-a-half (bungalow style) house
• 2000 sq. ft. unfinished basement (future completion for aging parents)
• 4 Bdrm, 3 ½ bath house
• Tight, highly insulated home

In Mechanicals | Asked By Kent Jeffery | Apr 16 14
1 Answer

How do I prevent condensation on boathouse roof?

New boathouse roof placed - galvanized. No insulation, roof screwed directly to 1"x4" lengths that are tying the roof joists together. Previous roof was corrugated and galvanized and had no condensation, new roof is covered in condensation in the winter, seems OK in the warmer months. Location is Southern British Columbia, Canada. Boathouse is enclosed but is not airtight, plenty of ventilation.

In General questions | Asked By David | Dec 24 15
4 Answers

Sheetmetal HRV ducting vs Zehnder

(I did a search and did not find anything, so here we go. If this has been discussed here, pls provide a link. Thanks.) I was talking with an HRV guy today, and asked if a brand of HRVs he sells has gone to the Zehnder-type plastic ducting; I showed him my Zehnder setup last year. He said "There is no substitute for sheetmetal", and said the reasons why were not a 5 minute conversation so we should discuss it some other day. I'm having a hard time reasoning why Zehnder tubing is not as good at moving air as sheetmetal, and it sure is a lot easier to install.

In General questions | Asked By John Klingel | Dec 23 15
1 Answer

I am getting mixed info on spray foam insulation

I am in Louisiana. I have gas heaters and water heater in the attic. Should I insulate the ceiling of the house (attic floor) or the rafter in the attic (attic ceiling) ?

In Building Code Questions | Asked By john bahlinger | Dec 24 15
13 Answers

Rooftop solar breaks the buck a watt barrier!

Recent pricing for a ~5kw rooftop system in Australia have recently been hitting under $1.40 AUD (=$1 USD at today's exhange rate.) Even pipsqueak sized 1.5kw systems are costing only a buck-fifty USD per watt.


In the US the average price of rooftop solar is running $3.40/watt, more than THREE TIMES the cost of solar in Australia, using the same panels, inverters, and racking systems, with comparably priced labor markets:


It's only a matter of time before the US

In Energy efficiency and durability | Asked By D Dorsett | Dec 21 15
5 Answers

Help! Building a log home in southeastern British Columbia, Canada

If anyone out there can help us - we would be very grateful. We are building a 2400 Sq Ft home in SE,BC Canada. 40x60 Cross Gable Roof. We are in Zone 6 - would like to insulate the roof to R52 or higher. Have decided to proceed as follows.

In General questions | Asked By Mark | Dec 23 15
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