I am not an energy Rater .. I am an architect

I am curious if any "Home Energy Pros" make an effort to locate the Neutral Pressure Plane (NPP) of a house that is being blower door tested?

Views: 2755

Reply to This

Replies to This Discussion

Don, I agree, I agree,

As for actually pointing to an elevation and saying the NPP is about here, somewhere in one of these posts I explained how to do that and it is rather easy.  All that is necessary is a ▲t and a manometer.  From inside and outside temperatures, a stack pressure per foot can be calculated.  Then, by taking a high or low pressure reading (that's where the pressure will be the largest) through the envelope, you have it.  If the front door reading is 2pa and you had calculated a 0.25pa per foot stack pressure, then the NPP is 8' above the penetration at the front door.

If you want to get fancy and you have a good ▲t, you can open a window a measured amount and, just like the "add a hole" process for pressure diagnostics, you can estimate the CFM50.  I keep baiting people with this in hopes that someone will do the math for me :).  My to-do list it too long.

As for the metal capillary tube, you can't get too small as a manometer does require a flow of air.  I would have to ask to be sure.  Just an FYI.

Bud

PS, I have started another thread to get into this issue a bit more: http://homeenergypros.lbl.gov/forum/topics/controlling-passive-air-...

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

Energy Center University posted an event

Better Buildings: Better Business Conferences at Crowne Plaza Chicago O'Hare Hotel & Conference Center and Kalahari Resort and Convention Center

February 26, 2015 to March 13, 2015
Better Buildings: Better Business ConferencesFebruary 26−27, 2015 │ Rosemont, ILMarch 11−13, 2015 │…See More
9 hours ago
Kris Grube added a discussion to the group Job Board
Thumbnail

Good Energy Retrofit, Portland, Or. Hiring Home Performance Salesperson.

Good Energy Retrofit is a small and focused, woman owned and operated, specialty residential…See More
13 hours ago
Benjamin Gromicko posted events
14 hours ago
Nate Adams joined Diane Chojnowski's group
Thumbnail

Hall of Shame

In this group, members share an array of images from the field, showing the kinds of issues…See More
15 hours ago
tedkidd commented on Diane Chojnowski's group Hall of Shame
"Give this thread a bump - here's my "bad" album and some of the…"
15 hours ago
Eric Kjelshus commented on Adam Swain's blog post Top Worst Crawl Space Insulation Ideas
"6) Radiant barrier- under the gravel is just a barrier but with holes each square inch its not a…"
16 hours ago
tedkidd replied to Luis Hernandez's discussion Distribution Efficiency and heating safety factor in TREAT in the group TREAT Software
"It is very common to find equipment grossly oversized. I mean 1.5 - 2x Manual J and 2-3x the size…"
16 hours ago
tedkidd replied to Luis Hernandez's discussion Basic Heat loss information in the group TREAT Software
"Luis,  Click "selected reports, energy savings and use, design heating and cooling…"
16 hours ago

© 2014   Created by Lawrence Berkeley National Laboratory.

Badges  |  Report an Issue  |  Terms of Service