Hi All,

I am trying to figure out a good flow grid system to use for testing airflow in 2 to 5 ton forced air systems.

Any favorites?

Or, if you prefer a flow-hood, please tell my why.

The flow hoods I've used take up more space in my vehicle than I would like.

Thanks for your thoughts.


Tags: flow, hoods, tools

Views: 143

Reply to This

Replies to This Discussion

I have 3 hoods - low flow ( 10-500 CFM)  Med flow (40-1500 CFM)  high flow (50-2000CFM) Open grid  for kitchen hoods. Plus hot wire plus presser plus other testing tools.   I test the air flow 3 ways  on each major job just to make my point or so I do not mess up.    Flow hoods have been used for 70 years and there's a lot of groups to help get it right.   look at http://www.trutechtools.com ,  www.nationalcomfortinstitute.com,  www.nebb.org,  https://www.aabc.com/www.tabbcertified.org.  I hope this helps some 80% air systems do not have the air flow to keep the unit on high limit.  

Thanks Eric!

Assuming that you're mainly interested in the total air handler flow, and you have access to the filter slots, I'd suggest looking at Energy Conservatory's TrueFlow.  It's a flat plate with openings; it has adapter plates for a variety of filter slot sizes. You'll also need to drill a hole in the supply plenum (or otherwise get a pressure tap in there).


I like the flat true flow plate when it fits-  if not the by pass is very very large.   Or if the presser is to high  its off some.   I have used 4 True flow plates  on a 2 ton spit system to find air flow.    Quick way is just use paper work that comes with the air handler ( you know the knee pad that come with the unit)  find the right unit using the right MO #  then total CFM reading the fan performance data at a constant speed chart.  to find Total SP use your blower door meter with a SP gauge both side of  motor, 3 of 10 will be off with high turbulence.  Have some fun with it and write about it I will be looking for your comments. 

If you wanted more information on the TrueFlow plate, the manufacturer is offering a webinar on it today: https://events-na11.adobeconnect.com/content/connect/c1/1097690081/...


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

Grzegorz is now a member of Home Energy Pros
2 hours ago
Rod Fox replied to Rod Fox's discussion Utility Meter Accuracy
"Dennis, that's a ton of useful info and it will take me a bit to fully assimilate those…"
3 hours ago
Ben Haas replied to Rod Fox's discussion Utility Meter Accuracy
"Yup..... 1200 amp service to the compound.....  3 -400 amp panels, all single phase since 3…"
15 hours ago
Walter Ahlgrim replied to Rod Fox's discussion Utility Meter Accuracy
"The more I think about it if the problem cannot be the current transformers reading small loads,…"
20 hours ago
Dennis Heidner replied to Rod Fox's discussion Utility Meter Accuracy
"Note to readers 0.5A instead of 5A for reading with A/D.... the edit to correct that didn't…"
21 hours ago
Dennis Heidner replied to Rod Fox's discussion Utility Meter Accuracy
"Rod, I have some of the CT's that you referenced in the openenergymonitor system.  They…"
21 hours ago
Tauran Ivall replied to Tauran Ivall's discussion Energy Efficient Entry Door options out there?
"Graham, How did this Plasproinc door cost?  Do you have any photos you can share a link to?"
21 hours ago
Dennis Heidner replied to Rod Fox's discussion Utility Meter Accuracy
"1200A service... really?  or did you mean 200A.  That size service would likely result in…"
22 hours ago

© 2015   Created by Lawrence Berkeley National Laboratory.   Powered by

Badges  |  Report an Issue  |  Terms of Service