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: 603

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

Bud Poll posted a discussion

CO poisoning in Yarmouth Maine

A news headline caught my attention, "Man hospitalized for signs of carbon monoxide poisoning at…See More
13 minutes ago
Profile IconEinar Johanson, patrick berta, Jerry Braun and 3 more joined Home Energy Pros
39 minutes ago
Casey Gesell added a discussion to the group News & Announcements
Thumbnail

Looking for home improvement companies to join our dealer network!

My name is Casey Gesell and I'm the Business Development Manager at Dr. Energy Saver, Inc.Dr.…See More
5 hours ago
Nate Adams posted a discussion
15 hours ago
Empower Efficiency added 2 discussions to the group Job Board
19 hours ago
john bustos posted photos
19 hours ago
john bustos posted an album

Items/Issues Found In Attics

Pics of deficiencies we have come across.
19 hours ago
Benjamin Gromicko posted blog posts
20 hours ago

© 2015   Created by Lawrence Berkeley National Laboratory.

Badges  |  Report an Issue  |  Terms of Service