New Anemometer for $16 to measure CFM & Temp works great!

Hello
This is cool!
https://www.amazon.com/gp/aw/d/B072...15&pi=AC_SX236_SY340_QL65&keywords=anemometer
This is a very necessary tool for any forced hot air heating or cooling appliance!!

You can test all the heat levels on the front of the pellet stove!!!

So I just measured the diameter of the little fan blade opening on the meter as about 2.7 centimeters which makes the radius 1.3 centimeters so that would be about 0.013 meters.
Now the area is Pi x Radius Squared = 0.057 Meters Squared
So the CFM = Area in Meters Squared x feet per min,
So CFM for the Englander Blower I measured on the exhaust flange is:
CFM = 0.057 x 1855 = 105.7
I know the Englander blower specs are 85 CFM so I am close but I am not sure where it is measured and my approximation of the area of my meter may be off also but for $16 I am not complaining!!!

What do you guys think???

Any more info on this meter for better CFM calculations?

Pic 1 - floor register with Harman on low flame!
Pic 2 - brand new Englander 85 CFM Exhaust Blower on Venting flange for a baseline to compare an old or dirty stove!
Baseline Feet per Minute measured here is approx 1855 ft/min

 

Hmmm...
Not sure. Seems like you're mixing metric and standard units. Is there a conversion factor between square meters and square feet figured in there? 1 inch is 2.54 cm.

It seems like you'd want to use pipe radius? 1.5 inch radius for 3 inch pipe? Some of the blower output is bypassing the fan in the meter.

1.5 inch/12 = 0.125 ft.
0.125 x 0.125 x π = 0.049 ft^2
0.049 ft^2 x 1855 ft/min = 91 ft^3/min



Sent from my XT1055 using Tapatalk

 

I think the air that passes thru the meter must be used in the calculations but a larger meter with a 3 inch diameter fan would be ideal.
However, I am just trying to get a baseline for the 85 CFM Exhaust Blowers and if that is in just in wind speed like 1855 ft / min that is just fine. So I can test older stoves and they do not measure up then I can suggest replacement. I also found that the stronger 1.75 amp Motors with the tall blades measure 2250 ft / min so it gives me some numbers to compare with!!
Then I can get baselines for the Convection blowers.

 

I gave an explanation about blower cfm,on other site,sorry,it will explain some things to you,Don.Very handy tool,especially for long range shooting.

 

Thanks Bob - I like your explanation of the way they spec the motors with a large test adapter right at the motor and the fact that since I am taking the measurement on a small 3” exhaust flange with the motor in the Exhaust Housing will increase the wind speed and give the higher than rated spec of 85 CFM.
That shows the calculations are in the right Ball Park! Thank-you!!!

 

You strive to make things better,I admire you.Keep up the great work,sir.