Results 1 to 12 of 12
  1. #1
    Join Date
    Feb 2012
    Location
    independence mo
    Posts
    4

    Question velocity meter??

    Hello, I need some realworld advice on buying a velocitymeter or anemometer (ime sure i spelled that wrong i cant even say it!) basicly i need a tool to measure airflow from ducts, drop across coil etc.. from what i have seen these are kind of pricey tools. I dont have a problem spending the $$, I just dont want to get some junk tool that isnt going to last.so any insight into what you are using would be much appreciated. thanks jimmy g.

  2. #2
    Join Date
    Mar 2012
    Location
    West Chester, PA
    Posts
    511
    There are alot of options when it comes to this stuff. The first step is to get an idea of exactly what you will be doing...are you doing service/diagnostics or balancing? personaly i think the rotating vane anenometer is the worst choice. A nice dual port manometer with static pressure tips can be used to determine press drops across coils and total ESP. This information can provide you with airflow through the unit as well as diagnostics on dirty coils, filters, undersized duct work, etc.. determining CFM with a manometer requires a blower performance chart or calibrated resitance chart. You can also use the manometer to determine velocity and then multiply it by the duct dimensions, if needed. Also you need a manometer to test gas pressure so....
    A hot wire anenometer is better than rotating vane. It gives you velocity but can be inserted into a duct trunk (unlike vane type) you still have to do the math on the duct work. Fieldpeice makes a hot wire anenometer that you can tell the duct dimensions and it gives your the true CFM. it's about $300. They also make a heat that does hotwire anenometer and manomter which would be the best of both worlds. A air flow hood is another option but not usually carried by service techs it is more for balancing and can usually only be used on outlets (not induct)

    in the end i think dual port digital manometer (i like fieldpeice) is a solid bet and then maybe a hotwire anenomter (in duct style)

    flow hoods and rotating vane items don't allow for in duct diagnostics and so have limited uses...

  3. #3
    Join Date
    Oct 2008
    Location
    Fullerton
    Posts
    743
    Quote Originally Posted by pckash View Post
    Hello, I need some realworld advice on buying a velocitymeter or anemometer (ime sure i spelled that wrong i cant even say it!) basicly i need a tool to measure airflow from ducts, drop across coil etc.. from what i have seen these are kind of pricey tools. I dont have a problem spending the $$, I just dont want to get some junk tool that isnt going to last.so any insight into what you are using would be much appreciated. thanks jimmy g.
    Here is the link to our In-Duct products... The STA2 is the in duct hot wire anemometer that measure air velocity and calculates the CFM based on the size of duct you set it for.

    http://www.fieldpiece.com/in-duct

  4. #4
    Join Date
    Aug 2009
    Location
    Peoria IL
    Posts
    72
    I really like my testo 416

  5. #5
    Join Date
    Oct 2008
    Location
    Fullerton
    Posts
    743
    Quote Originally Posted by RussellHarju View Post
    Here is the link to our In-Duct products... The STA2 is the in duct hot wire anemometer that measure air velocity and calculates the CFM based on the size of duct you set it for.

    http://www.fieldpiece.com/in-duct
    The Fieldpiece STA2 MSRP is $349.00

  6. #6
    Join Date
    Jul 2006
    Location
    NW burbs of Detroit
    Posts
    6,058
    Quote Originally Posted by RussellHarju View Post
    Here is the link to our In-Duct products... The STA2 is the in duct hot wire anemometer that measure air velocity and calculates the CFM based on the size of duct you set it for.

    http://www.fieldpiece.com/in-duct
    That one's a keeper for sure.

  7. #7
    Join Date
    Dec 2006
    Location
    Goodyear, AZ
    Posts
    194
    I like the Fieldpiece AAT3

  8. #8
    Join Date
    Feb 2012
    Location
    independence mo
    Posts
    4
    wow many thanks to all. I am just blown away by the response time. excellent views and opinions. i have been studying these things for a couple weeks now and i learned more in thirty minutes here. Once more thanks to everyone here.I just wish i would of found this site a long time ago. Jimmy g,

  9. #9
    Join Date
    Jan 2005
    Location
    Akron
    Posts
    975
    Quote Originally Posted by ADillon View Post
    There are alot of options when it comes to this stuff. The first step is to get an idea of exactly what you will be doing...are you doing service/diagnostics or balancing? personaly i think the rotating vane anenometer is the worst choice. A nice dual port manometer with static pressure tips can be used to determine press drops across coils and total ESP. This information can provide you with airflow through the unit as well as diagnostics on dirty coils, filters, undersized duct work, etc.. determining CFM with a manometer requires a blower performance chart or calibrated resitance chart. You can also use the manometer to determine velocity and then multiply it by the duct dimensions, if needed. Also you need a manometer to test gas pressure so....
    A hot wire anenometer is better than rotating vane. It gives you velocity but can be inserted into a duct trunk (unlike vane type) you still have to do the math on the duct work. Fieldpeice makes a hot wire anenometer that you can tell the duct dimensions and it gives your the true CFM. it's about $300. They also make a heat that does hotwire anenometer and manomter which would be the best of both worlds. A air flow hood is another option but not usually carried by service techs it is more for balancing and can usually only be used on outlets (not induct)

    in the end i think dual port digital manometer (i like fieldpeice) is a solid bet and then maybe a hotwire anenomter (in duct style)

    flow hoods and rotating vane items don't allow for in duct diagnostics and so have limited uses...
    When you are describing a vane, you are talking a large vane I assume, and deal with mostly hard ducted systems. A vane is one of the best tools for airflow you can get for several reasons. Vanes come as small as 1/2" in diameter.

    The primary advantages of vane anemometers are speed, accuracy, and ease of use. Vane anemometers do not require air density compensation due to air temperature, humidity, or atmospheric pressure. The mini vane allows for a full duct traverse with an automatic calculation of the CFM in the duct if the dimensions are input into the instrument before the measurement is taken. If done carefully the measurement error will be less than 3% and often as little as 1%total error. Changes in yaw and pitch of the probe head in the duct as much as 10% will result less than 1% error in the measurement making the mini-vane an ideal probe for field air measurement. Because of the larger probe size compared to a Pitot tube tip or hot wire, stray eddy currents will have little effect on the final measurement.

    We sell 100's of large vanes a year to contractors that deal with central return flex ducted systems. A large vane is the perfect tool again for this reason. There is no better way to measure airflow in this type of system.

    Each type of airflow measurement tool has its ideal applications and ideal measurement range. When considering hand held instrumentation, typically hot wires are suited for very low velocity measurements, vane anemometer for mid level and Pitot tubes for high velocity measurements. While all of these have some overlap, we have found the vane to be one of the most useful tools when trying to select a single instrument for multiple applications typical to residential and light commercial applications. For air balancing and quick measurement consider a capture hood. While they are initially more expensive, if you do a lot of air-side work, there could be considerable labor savings.

    Here is how a mini vane is used to measure airflow.

    JLB,

  10. #10
    Join Date
    Dec 2006
    Location
    Goodyear, AZ
    Posts
    194
    Quote Originally Posted by RussellHarju View Post
    The Fieldpiece STA2 MSRP is $349.00
    This in duct hot-wire anemometer quickly calculates CFM from air velocity and free area. And with the intuitive interface, the STA2 makes it easy to capture the correct data.

    •Measures air velocity and temperature
    •Calculates CFM
    •Slim 38" telescoping probe for in duct traversing
    •Fast response time
    •Dual display for combo of real-time CFM, air velocity, or temp
    •Depth and direction indicators
    •Minimizes turbulence effect with time/test point averages
    •Hands-free testing with stabilizing cone and magnetic hanger

    With ease, techs can input free area, and the STA2 automatically averages multiple test points and continually calculates and displays CFM.

    http://www.shop.rdholder.com/Fieldpi...piece-STA2.htm

    RD Holder owner of shop.rdholder.com
    5% off with hvactalk code

  11. #11
    Join Date
    Mar 2006
    Location
    Denver/Boulder
    Posts
    2,213
    Quote Originally Posted by pckash View Post
    Hello, I need some realworld advice on buying a velocitymeter or anemometer (ime sure i spelled that wrong i cant even say it!) basicly i need a tool to measure airflow from ducts, drop across coil etc.. from what i have seen these are kind of pricey tools. I dont have a problem spending the $$, I just dont want to get some junk tool that isnt going to last.so any insight into what you are using would be much appreciated. thanks jimmy g.
    The first, foundational tool you need for measuring airflow is a manometer. It is used to read Static pressure, most commonly in inches of water column (in W.C.) or Kilopascals (kPa)

    you also need to measure Wet and Dry blub temperatures. You probably Have an adequate dry bulb thermometer, but will need a wet bulb.

    Only after you have built experience with these three tools would I suggest moving on to a pitot tube, hot wire anemometer, or vane anemometer.

    Mastering a manometer and static pressure tips is fairly easy to do over time, but you should measure numerous systems before you pronounce yourself competent. There are certain quirks to measuring airflow that you just have to experience for yourself before you start to understand what makes an accurate reading and what doesn't.

    Start with a digital manometer. You should have one of those for diagnosing a furnace or boiler anyway.

    I have used, and liked both the Testo 510, and the Uei EM201. Also the Dwyer Magnahelic. Before I had to buy the Uei in a pinch I never would have been caught dead with one of their meters, but i must admit that it is pretty decent. There is very little purpose in buying a analog Magnahelic any longer, but they are still out there.

    If I had to buy right now I would look at

    the fieldpiece SDMN5 (measures up to 60 in WC/ 2 PSI and that's great for gas/ I wonder how fast the response time is....

    the Testo 510, small (read CRAZY small), temperature compensated, and will do FPM for pitot tubes too. On the down side the pressure only goes to 40 in WC. Also slower than the Uei.

    The UEI EM201- bulky, rugged. good magnet and protective cover. The response time is much faster than the Testo 510. WAY faster. I caught a gas valve acting flaky with the UEI that the testo couldn't pick up. 40 in WC also


    One Last note on learning to use manometers...

    I learned the hard way that one should use a SINGLE static pressure tip and add/subtract the numbers manually to arrive at my differential measurements. I collected more information and got more accurate readings that way. I know it seems way 'cooler' to let the meter do the work, but trust me when I say that air is a very fickle thing to measure and paying attention to measuring one point at a time gets better results.

    After you get used to measuring the way the books tell you to, you can start to measure other parts of the system and compare that information with what you get through other means of measuring air you really start to learn a bunch!!!

    Very little of this is taught in the classsroom, you have to go someplace cool like hvac-talk


    Stick around and ask more questions.
    Last edited by darctangent; 07-02-2012 at 02:20 AM.
    What lies behind us and what lies before us are small matters compared to what lies within us.


    Two pressures, four temperatures = SUCCESS!


    Boulder Heating Contractor


    For Consumers:

    For HVACR Professionals:


  12. #12
    Join Date
    Jan 2007
    Location
    Mn the state where absolutey nothing is allowed
    Posts
    1,312
    great advive, thx darc, i have to add, the dwyer 475 is a damn nice manometer, the fieldpiece SDMN5 does have its quirks, it doesnt remain stable with minimal temperaturew changes' also measuring a 2 psi gas pressure system does not require that degree of accurace that air flow measurements do. i use a 100" spring gauge for that. that is good enough to determine a gas pressure problem.

    yes one reading at a time but do not buy a single port manometer. you have to have one for gas furnace pressure switch testing.

    for static checks i completely agree to take only 1 reading at a time so you can get a feel for where a problem lies.

    my boss thinks its possible to repeal the laws of physics

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event