Do you work on qualifying homes for ENERGY STAR? If so, what do you think of Version 3? I'm going through a 2-day session in Raleigh this week on the new guidelines and the training that will be required of raters and have just written up a blog post about the first day. You can check it out at:
I think Version 3 incorporates more concrete building science and techniques into the program, but more checklists will be needed. The Version 2 program required the thermal bypass checklist, and this new version requires more work on behalf of the mechanical contractor. From what i've heard talking with homeowners and program managers, HVAC is the area that most needs improvement. Heating and cooling is 46% of our home energy use; it's the reason why people have major comfort issues; and there's signficant room for improvement, starting with correct sizing of the AC and ducts, proper sealing, closed combustion, heat flow, etc...
You're absolutely right, JC. HVAC is the hardest part to get right in programs like ENERGY STAR. There are a lot of factors at work that make it so, and it's definitely a good thing for ENERGY STAR to be raising the bar.
I just wrote up my review of Day 2 of this class, which you can read by clicking the link at the bottom of the Day 1 review, which I've linked to above.
I'd like to believe it's impossible, too, JC, but Scott Suddreth is one person in this field who has earned the utmost credibility. I don't know the details (number of houses, magnitude of leaks...), but Scott definitely knows what he's doing. I'm with you, though. It sure seems hard to believe.
i worked in Weatherization Asst Program for a few years and we found gas leaks very seldomly. We certainly did find some so it's worthwhile to check, absolutely, but much less than 10% of the homes had leaks, maybe even as low as 3%.
I think it might depend on how slowly you check the line and how finely the gas leak detector is calibrated. In trainings we have had 10 people check the same gas line with no problems and then the 11th person finds a leak by going much more slowly and carefully and having the calibration set more finely. After that everyone can find it. This is going tediously slowly (1 inch per second), whereas some trainers teach to go at 1 foot per second. Maybe that's where the differences of opinion come from?