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: 3311

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.  Home Energy Pros is sponsored by the Better Buildings Residential Network.

Latest Activity

Richard C. MacCrea replied to Damien Greenfield's discussion Is there is cost saving for you in having a tankless water heater?
"Most of the posts here are far too narrow in scope. To make the best decision you need to…"
8 hours ago
Tom Mallard replied to Damien Greenfield's discussion Is there is cost saving for you in having a tankless water heater?
"Thx, Jose, add in u"
9 hours ago
tedkidd replied to Damien Greenfield's discussion Is there is cost saving for you in having a tankless water heater?
"Thankless water heaters are a GREAT deal.... For the installers. They are usually very…"
10 hours ago
Jose Carreno replied to Damien Greenfield's discussion Is there is cost saving for you in having a tankless water heater?
"I have been working with RUUD/RHEEM tank less water heaters (0.94 energy factor) with excellent…"
13 hours ago
Profile IconColleen Neel, Sarah Mostafa, Michael Kelemen and 4 more joined Home Energy Pros
14 hours ago
David I. Shepherd-Gaw replied to Ryan Miller's discussion Wouldn't it make more sense to post jobs on a single board nationally? in the group Job Board
"I have managed and overseen several efforts with www.energyexpert.org and other similar sites. It…"
14 hours ago
David Baerg replied to Bachi Brunato's discussion Modeling a Gas Fireplace in Wrightsoft
"I would not include it.  Given that it is likely much less efficient than the gas furnace, you…"
16 hours ago
Ryan Miller posted a discussion

First NC and now GA - Building Performance Associations taking shape

Hi All - Just a quick "this is what we're up to" for the community.The NC Building Performance…See More
16 hours ago

© 2015   Created by Lawrence Berkeley National Laboratory.

Badges  |  Report an Issue  |  Terms of Service