HVAC Monitoring Equipment Options

you get what you pay for, go cheap and that's exactly what you'll get

"I am looking at buying a air velocity meter... but my company wants me to buy the cheapest one I can."

That sounds pretty simple to me. Have you checked a few garage sales?

Okay, okay... is this tool an important part of your business, providing these tests, or is this for some occasional balance checking?

we had our building "balanced" by a company when we first moved in but there are some areas that don't seem right, we are looking to verify this, and make changes as needed but want to gather data we can trust as opposed to just hiring another company to check it.

if you paid for an air balance they gave you a report on their findings. basically their job is to test and verify that each duct is providing the amount of air in CFM that was spec'd on the plans, if they match but the building still isn't conditioned correctly either the install was weak or the design was poor to begin with, a close look at the report you already paid for should give you a good starting point. and heres a pic of the proper tool, an air hood

Well, balancing the HVAC of a building is sort of a dark art.

After you determine the varied flows, what will that information tell you? After you have interpreted the information, how do you go about adjusting things?

There are special TAB contractors who specialize in exactly this. I would give this fact alone some serious consideration.

However, if you (or the management team) wish to do this yourself, why not just get the least expensive tools and be done with it?

I've always thought Flukes were overpriced. I guess it depends on the level of accuracy really required.

Want does it really have to do? How much accuracy do you REALLY NEED?

If, "my company wants me to buy the cheapest one I can" is true then go here:

Air Velocity Meter | eBay

Look for a third option, then recommend the mid-priced unit, as the cheapest is 'obviously' too cheap to be accurate, and the dearest is overpriced for the accuracy required.

I have never been a fan of the most expensive measuring instrument necessarily being the most accurate and not a fan of high-priced Fluke. It is usually a case of defining what I want to measure, how accurate I want to measure and the technique of the measurement process or calibration.

From a quick scan of the readily available specs of the 2 instruments, here is a simple comparison;

Extech Hot Wire Anemometer Meter

Air Velocity
m/s 0.2 to 25m/s: ±2%rdg

Temperature
32 to 122°F (0 to 50°C): ±1.5°F (±0.8°C)

Type K temperature
-148 to 2372°F (-100 to 1300°C): ±(0.4% + 1.8°F/1°C)

Type J temperature
-148 to 2192°F (-100 to 1200°C): ±(0.4% + 1.8°F/1°C)


Fluke 975 AirMeter specifications

Temperature -20 °C to 50 °C
± 0.9 °C/± 1.62°F from 40 °C to 50 °C
± 0.5 °C/± 1.00°F from 5 °C to 40 °C
± 1.1 °C/± 1.98 °F from -20 °C to 5 °C

Air velocity
0.50 fpm to 3000 fpm: ± 4% or 4 fpm*
0.25 m/sec to 15 m/sec: ± 4 % or 0.02 m/sec* whichever is greater

*Accuracy specification only valid for velocity readings above 50 fpm

Which device better suits your measurement requirements.

The original design was overkill and was trimmed by management for financial reasons, and compromises were made some are causing process problems. We had a fair amount of undocumented changes that were made on the fly during install, so drawings are not accurate and the company that balanced the building has been totally uncooperative. so we need to measure what the current situation is, before we can begin to make a plan.

Extech equipment has always underperformed anytime i was forced to use it, To stay on topic I won't even describe the lemon of a photo tachometer that sits in my cabinet gathering dust. We replaced an Extech anemometer 3X and paid for calibration 3X (it was replaced under warranty each time, however we had to keep paying for the calibration), we ended up with TSI/Alnor and it has worked so well that we bought a second one and have 2 teams testing with these with zero failures in 10 months (They are hard on these and they get used almost daily). Extech multi-meters are ok however there are lots of affordable manufacturers in that market. Extech was purchased by FLIR some time ago and hopefully they will improve the reliability of the anemometers in their product offering. TSI specializes in Air Flow Measurement, they know the industry and have a product that is designed to perform accurately and reliably.

TSI/Alnor also makes Air Measurement Hoods, It sounds like that may be more what you will need. We have 2 of those as well and they work great. They will cost you considerably more however.

This is the kind of help I was looking for (other opinions about this test equipment) thanks for posting