When doing a blower door test, do you ever use long term average? Why or why not?

Digital pressure and flow gauges have an option for time averaging, such as 1, 5 or 10 seconds, long term or a manual time average option.

Under what circumstances would you use the long term average and why?

Views: 149

Reply to This

Replies to This Discussion

When the wind is breezy, I use long term averaging. The more the pressure jumps around due to breezes, the longer the term that I use. Even then, I mentally average the readings. This is after I have taken steps to shield the end of the outside hose from the wind.

Hi Kim,

Wind is probably the most frequent reason for using the time averaging with our manometers, but there is another that we need to be careful with.  Manometers are unique in that they ignore barometric pressures.  Place your refer tube out the front door and walk your manometer (long tube) upstairs or into the basement and even though the top to bottom pressure may vary (on a cold day) by 50 pascals or more our manometers will register very little.  When the temperature of our tubes and the air inside is the same as in the house, any changes in elevation are canceled out.  However, if those tubes just came out of an ice cold vehicle, or a hot one, and have not fully acclimated, our readings will drift.  In this case, before we start averaging we need to allow those tubes to become room temperature.  The section of tube that goes outside needs to acclimate as well.

Bud

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

Susan E. Buchan's event was featured

EEBA Excellence in Building Conference at Doubletree Union Station Hotel

September 23, 2014 at 8am to September 25, 2014 at 2pm
13 hours ago
Susan E. Buchan posted an event

EEBA Excellence in Building Conference at Doubletree Union Station Hotel

September 23, 2014 at 8am to September 25, 2014 at 2pm
14 hours ago
Rem Husted replied to Andy Gostisha's discussion Disguising Ductless Heat Pump Units
"I think most consumers wouldn't want a big box called a refrigerator or a stove or…"
14 hours ago
Scott Katznelson replied to Scott Katznelson's discussion Database of zip code or county by climate zone
"You know those maps you can find for energy code climate zone specific reference.  That's…"
15 hours ago
JEFFREY M HUGO, CBO replied to Richard Beyer's discussion Sprinkler Mandate Debated.. What do you think should be done?
"Fire sprinklers operate when the fires are small. Typically it only takes approx 20 gallons per…"
15 hours ago
Scott Katznelson replied to Scott Katznelson's discussion Database of zip code or county by climate zone
"Thanks.  That's the best source I've yet found, and maybe the best that's out…"
15 hours ago
Diane Chojnowski replied to Scott Katznelson's discussion Database of zip code or county by climate zone
"I posted the question on HEP's facebook page and Bill Spohn commented: Try…"
16 hours ago
Profile IconKevin Jordan, Hannah Strong, Rich Snyder and 1 more joined Home Energy Pros
yesterday

© 2014   Created by Lawrence Berkeley National Laboratory.

Badges  |  Report an Issue  |  Terms of Service