David Richardson posted an interesting piece on changing from % based testing based on conditioned floor area versus the duct area

http://ncidavid.blogspot.com/2013/10/should-duct-surface-area-be-us... 

Personally I see quite a few problems with this based on the way things are done now, but I am curious what you all think.

As for some of my concerns - most installers have no clue what the duct area is because we cant even get them to do a Manual J much less a D (sorry I also have no desire to run a tape against them either)

Leaving the air handler out means more sloppy installs of them & manufacturers wouldn't have to concentrate on making them by default tighter

With that he does make some very valid points & I would love to hear your thoughts

Views: 546

Replies to This Discussion

Interesting thought but the issue with that is contractors bumping up manual J's for bigger units - the 99 occupants, leaky house, etc... tricks we have all seen used to get to there favorite 400 or 500 SF per ton. Granted commercial never sees this issue but that is because they require a mechanical engineer in many cases & also have higher loads than residential due to ventilation requirements

I think John has it nailed - 6% total (at final) & 10% for inside conditioned space (especially for "balanced" systems where they have actual returns in each room) with maybe a max based on nominal airflow. Shoot to make it fair for smaller houses  to promote them maybe even go 8% for homes under 1200 SF. As for reporting, I think it should be both the % but also as Ted points out - actual leakage numbers 

RSS

Home Energy Pros

Home Energy Pros was founded by the developers of Home Energy Saver Pro (sponsored by the U.S. Department of Energy,) and brought to you in partnership with Home Energy magazine.

Latest Activity

Jim Gunshinan commented on Jim Gunshinan's blog post My Energy Upgrade California—The Numbers Are In
"Thanks Nate for more good stuff to chew on—and nutritional! We may be running out to Home…"
7 hours ago
Tom Conlon commented on Jim Gunshinan's blog post My Energy Upgrade California—The Numbers Are In
"Jim,I just got around to re-reading your four-part series and I think this is a really interesting…"
8 hours ago
Nate Adams commented on Jim Gunshinan's blog post My Energy Upgrade California—The Numbers Are In
"$50 in health ain't much... not with my crappy high deductible plan. It buys half of a cold…"
8 hours ago
tedkidd commented on Jim Gunshinan's blog post My Energy Upgrade California—The Numbers Are In
"Yep, this thread has some good discussion. Back to dehumidification.  This may be…"
12 hours ago
Jim Gunshinan commented on Jim Gunshinan's blog post My Energy Upgrade California—The Numbers Are In
"Thanks for the clarification Nate. If I had the ability to precisely measure what $50 of health…"
13 hours ago
Nate Adams commented on Jim Gunshinan's blog post My Energy Upgrade California—The Numbers Are In
"Jim, Just a clarification, it's not DEhumidification I'm worried about in your climate,…"
13 hours ago
Chris McTaggart posted events
13 hours ago
Jim Gunshinan commented on Jim Gunshinan's blog post My Energy Upgrade California—The Numbers Are In
"Hi Nate, I'm glad this post has generated so much good discussion, since that is its main…"
14 hours ago
Diane Chojnowski's group was featured
Thumbnail

Facebook Pages

Does your company or organization have a Facebook Page?This group is for pros who have facebook…See More
14 hours ago
Tom White joined Diane Chojnowski's group
Thumbnail

Facebook Pages

Does your company or organization have a Facebook Page?This group is for pros who have facebook…See More
14 hours ago
David Valley's photo was featured

ceiling_infrared

Cold air infiltrating the lower right portion of this wall and ceiling.
14 hours ago
Christopher Morin's 2 blog posts were featured
14 hours ago

© 2014   Created by Lawrence Berkeley National Laboratory.

Badges  |  Report an Issue  |  Terms of Service