cfm measurements with Digital Anemometer?

[acguytx]

Ok so i was looking at buying one of these and want to know some that are good some to stay away from and also do tese all have issues with needing professional expensive calibration?

I would like one that actually has CFM on it so i didnt have to use a calc from FPM to cfm..

Extech CFM/CMM Thermo-Anemometer looks like a decent one but may need calibration , which ones do not? these things range from $50-600 buck all being basic with just wind speed all the way up to multi function.. is this the best way to get cfm at supply's and such so i can get total cfm for the house and balance the duct cfm output?

input on what you are using, have used and some good and bad on the ones out there?

[acguytx]

BTW i have a testo 510 manometer and I ordered a 18inch pitot tube that you can PUT INTO DUCT , what exactly does this measure, im not talking about the static tips but the big pitot metal tube, is this a way to measure cfm somehow?

[Pascone10]

BTW i have a testo 510 manometer and I ordered a 18inch pitot tube that you can PUT INTO DUCT , what exactly does this measure, im not talking about the static tips but the big pitot metal tube, is this a way to measure cfm somehow?

yes with a pitot tube you can do something called traversing the duct. However you need a straight run a certain distance from a 90 or transition. sometimes hard in some applications. Do you use blower fan curves?
What type of systems are you working on?

[Ed Janowiak]

I have had good success with a Testo 416 to measure both system CFM as well as branch run (metal) volumes.

So easy to use a kid can do it.

[jim bergmann]

Being in Texas, you need a big anemometer 417.. No joking. You guys deal with a lot of flex in the attic. A large vane is used to measure airflow at the returns. The 417 will allow you to measure at the grill and calculate the CFM directly even with multiple grills. It is easy to use.

[Pascone10]

how do you do it? I havnt seen you around in a while and now there is a air flow question and here you are lol. Nice to see you again .

Since were in this topic how does this tool work? Never seen it.
How does it compare to a hot wire? I know you have to factor in for air density with the hot wire but never knew how to do it.

to the op not to steal your post, I believe these questions related to your question..

[acguytx]

yes with a pitot tube you can do something called traversing the duct. However you need a straight run a certain distance from a 90 or transition. sometimes hard in some applications. Do you use blower fan curves?
What type of systems are you working on?

just your basic run of the mill residential AND LIGHT COMMERCIAL. i just want BETTER WAY to diagnose loud ducts or systems with high static , a better way of balancing the individual duct runs in those instances.

Jim ill call you tomorrow, thanks for the heads up.

[fcs]

Ok so i was looking at buying one of these and want to know some that are good some to stay away from and also do tese all have issues with needing professional expensive calibration?

I would like one that actually has CFM on it so i didnt have to use a calc from FPM to cfm..

Extech CFM/CMM Thermo-Anemometer looks like a decent one but may need calibration , which ones do not? these things range from $50-600 buck all being basic with just wind speed all the way up to multi function.. is this the best way to get cfm at supply's and such so i can get total cfm for the house and balance the duct cfm output?

input on what you are using, have used and some good and bad on the ones out there?

I have the TSI 8360 and the TIF VA500A Both will calculate CFM, I love the feature

[raidersfan7]

hey fcs whats the price of that meter where u gte it at ??/

[BobbyBJr]

Depends on what you are going to do with the instrument. If you are going to get into air balancing, then you will have to send it off for that expensive calibration you mention. I've been on jobs where I had to show proof that my meter had been calibrated in the last 6 months, but most are one year. I have TSI's 8386 and their 8355 as a backup. I also have Testo's 416 mini-vane and their 410 pocket meter. All four have given me good service, although all but the 8386 were purchased off of Ebay.

[raidersfan7]

nah im svc tech commericIAL... JUST WANNA GET A BASIC TOOOL TO MEASURE CFM

[ascj]

nah im svc tech commericIAL... JUST WANNA GET A BASIC TOOOL TO MEASURE CFM

I'm a commercial tech myself. I measure airflow for diagnostics, not trying to air balance. I use a dual input manometer and tachometer to verify equipment airflow. Then if needed I'll use an anemometer at the diffuser to get a rough estimate. I'll look up a similar style diffuser in Hart and Cooley's book to get my net free area to program into my anemometer and then take about 5 quick reading to average my cfm. It works fine for diagnostics.

My manometer- http://www.testo.us/online/abaxx-?$part=PORTAL.USA.SimpleContentDesk&$event=show-from-menu&categoryid=6102659

My Tachometer- http://www.testo.us/online/abaxx-?$part=PORTAL.USA.SimpleContentDesk&$event=show-from-menu&categoryid=6102657

My anemometer- http://amprobe.com/cgi-bin/pdc/viewp...id=1&type=elec

[fcs]

hey fcs whats the price of that meter where u gte it at ??/

Got the TSI off E-Bay I think I pay around $250 one heck of a deal (right plac right time.

the TSI also has a mamometer

got the TIF from Grainer about 5 years ago I think it was around $500,