Recent Q&A

• How to vent a crawl space — “Musings” article of May 13, 2011

  I'm going to take the advise in the "Building an Unvented Crawl Space" by Martin Holiday that was posted on May 13, 2011. It suggests putting a floor register in…

• Household humidity

  大量的数字。Thermostat reads 52% humidity, HRV control reads 49% humidity. The Hobo reads 56.5% relative humidity. The sling psychrometer has wet bulb 66, dry 72, which is 76%…

• Insulating truss joists 16″ on center — Best way?

  Batt insulation for 24" o.c. The 2x lumber is 23" wide. The truss joists I'm looking at are 2x4 lumber 24" o.c. The space between the trusses is 21.5". Does…

• Persistant smell in house dense packed with cellulose

  We insulated both attic and walls with cellulose. One bedroom that has the attic staircase in the closet develops an odor that the customer says "smells like the day you…

• Rated output for electric radiant ceilings?

  I've been searching the web for a rule of thumb to calculate the rated output for a 40 year old electric radiant ceiling system. Must be some rule of thumb…

• Spray foam – how thick to air seal a rim joist?

  What is the minimum thickness of spray foam on a rim joist for effective air sealing? I'm using a disposable 2 part 200 board foot kit.

• How to prevent check valve malfunction in a hydro-air system?

  I have a propane water heater with a loop to the air handler. Potable water goes through the coil. I noticed that my water heater would run twice an hour…

• Crawl space – Need advice

  Climate zone 5; 1,900 sq. ft. unvented crawl space. 3 feet clearance. Poured concrete walls and floor. Foil faced fiberglass batts in poor shape on joists installed incorrectly. Recently installed…

• Looking for good quality 3.25″ x 10″ wall cap with backdraft damper for kitchen exhaust fan – recommendations?

  Venting range hood straight out the wall - need a high quality wall cap to keep the cold air out.

• Is a LP hot water tank enough to heat my renovated house?

  I'm doing a deep energy retrofit on a 2000 sf ranch in Connecticut. I've having trouble getting a HVAC company interested. The first wanted to put a hi efficiency air…