Question Testing airflow & velocity: considerations (3 questions)

[ReveurGAM]

There are 3 things I'd like input on, please.

1. I just got done testing a Reed hotwire anemometer and, although this was 4+x more expensive than the previous two, it has fewer functions and there were several points on which I was not satisfied. That aside, I'm looking at 3 alternatives, having eliminated others with too small of a vane: Extech AN300, Extech AN310, and Cole-Parmer Digi-Sense 2025015 with NIST-traceable certification. The Extechs both have a 4" fan, while I can't find the fan size for the CP. None of the 3 provides data logging or real-time transfer, apparently. The CP seems to have a more user-friendly interface. The two Extechs are more sensitive: 0.2 to 30m/s for each, while the CP is .4 to 30 m/s. The AN300 and the CP two only do ambient temperature, while the AN310 also measures relative humidity, dew point and wet bulb. Another point about the CP that I'm concerned about is the long cable. If they've skimped on quality, then there may be a delay of a few seconds in both directions, like the Bonvoisin I tested. The Reed did well on increased speed but was delayed registering decreased speed, and seemed to hit a high and then drop (I'm wondering if that's typical of the hotwire).
   
   So, I'm wondering how important it is to have the extra features of the AN310 when testing fans...?
   
   
2. Which of the 3 would you suggest, or do you have a completely different one that is highly reliable and can measure as low as (or lower than) the Extechs?
   
3. Additionally, I'm quite interested in the idea of having an air flow cone, but the one for the Extechs costs more than they do for something that could be 3D printed! I have access to a printer, so that is possible.

 

[Ralston18]

More information needed:

How are you applying this to computers/IT?

Are you measuring fans flow velocity?

I am not sure that you posted in an applicable Forum or Category within this Forum.

Restate and clarify the problem.

 

[Deleted member 2947362]

what are you testing for? air flow and the efficiency of the conditioning with in a server room/s?
not that I can help was just interested as what would you need an anemometer for in relation to computers?

I could maybe give you limited help with the choice of a heat sink but that's about it lol

 

[ReveurGAM]

what are you testing for? air flow and the efficiency of the conditioning with in a server room/s?
not that I can help was just interested as what would you need an anemometer for in relation to computers?

I could maybe give you limited help with the choice of a heat sink but that's about it lol

More information needed:

How are you applying this to computers/IT?

Are you measuring fans flow velocity?

I am not sure that you posted in an applicable Forum or Category within this Forum.

Restate and clarify the problem.

If this is the wrong category, where should it be?

I'm testing computer fans (120-200mm). Yes, velocity and airflow, and at least ambient temperature. I'm doing various tests, including simulating obstructions, with and without a wind tunnel.

I have a way to indirectly determine relative static pressure, at least until I find a manometer that can do it.

 

[Deleted member 2947362]

so there is no better alternative than an anemometer ? I don't know, is that the best approach for testing the velocity and airflow of fans?

Quote
"I have a way to indirectly determine relative static pressure"

Wish I could help sounds like an interesting experiment.

I'm not sure maybe one of the Admin can advise on which part of the forum, if there is a part that can help you with this.

 

[Ralston18]

When I read "anemometer" my first thought was weather measurements of some sort.....

Computer fans - will stay with Cooling for now.

Possible that some other member has made efforts to measure fan performance via fan intake and exhaust wind speeds.

Likely you can make a small anemometer . For example:

https://www.instructables.com/Digital-Anemometer-wind-meter/

You would not be the first person who needed to make your own testing devices. And need to calibrate them for scientific use.

= = = =

Another option could be of of the small anemometers carried by explorers, hikers, scientists when wind velocities are of interest or concern.

Something like these devices (not a recommendation or endorsement):

https://www.walmart.com/ip/Testo-410i-Wireless-Vane-Anemometer-Smart-Probe-Technology/725505654

Portable anemometer

There are other similar products available.

 

[ReveurGAM]

so there is no better alternative than an anemometer ? I don't know, is that the best approach for testing the velocity and airflow of fans?

AFAIK, unless you have $10g lying around that you want to give me to buy a professional wind tunnel, no. 😉 Then again, I have no space, let alone a way to get it into my 3rd storey apartment! 🤣

Quote
"I have a way to indirectly determine relative static pressure"

Wish I could help sounds like an interesting experiment.

It is very time-consuming.

 

[ReveurGAM]

When I read "anemometer" my first thought was weather measurements of some sort.....

That is what they're for. I'm unaware of any company that makes anemometers for testing fans - not that that means there aren't any. As long as it's sufficiently sensitive and accurate, that's all that really matters aside from functionality.

Possible that some other member has made efforts to measure fan performance via fan intake and exhaust wind speeds.

Likely. It's rather a niche, although I've found a few (ThermalLeft, Ľubomír Samák, Aris of HW Busters, Linus Sebastian).

Likely you can make a small anemometer . For example:

https://www.instructables.com/Digital-Anemometer-wind-meter/

That particular type is not good for testing fans. AFAIK, only vane and hotwire are suitable - unless you have tons of money. Which I don't.

You would not be the first person who needed to make your own testing devices. And need to calibrate them for scientific use.

Definitely. I wish I had the skills to do that sort of thing.

I actually looked at that Testo (and a bunch more) but I wanted something that displayed the readings and had controls on it. I found this inexpensive option...Too bad it isn't what I need.

 

[Ralston18]

This:

"Definitely. I wish I had the skills to do that sort of thing."

You learn by doing. Try.

Are you in college? Look around for some electronics/IT /engineering type folks. Maybe someone needs a project and would be willing to help.

Are you expected to do some formal write up regarding the project and results?

Even if not in college - no harm in asking around.

= = = =

It all begs the question why are you doing this/the project?

If just for yourself then go forward as best you can and learn what you can. If things do not work out as expected then, again, try again. Learn, improvise, go forward.

If you have other reasons for doing the project then the anemonmeter issues etc. need to be discussed with any other parties (an advisor perhaps) involved with your project.

 

[ReveurGAM]

This:

"Definitely. I wish I had the skills to do that sort of thing."

You learn by doing. Try.

Are you in college? Look around for some electronics/IT /engineering type folks. Maybe someone needs a project and would be willing to help.

Are you expected to do some formal write up regarding the project and results?

Even if not in college - no harm in asking around.

= = = =

It all begs the question why are you doing this/the project?

If just for yourself then go forward as best you can and learn what you can. If things do not work out as expected then, again, try again. Learn, improvise, go forward.

If you have other reasons for doing the project then the anemonmeter issues etc. need to be discussed with any other parties (an advisor perhaps) involved with your project.

Thank you for the very supportive words. I do appreciate it!
I have tried for months to find someone who could help me design and build what I need. I'm not in university as I am old and prefer to learn on my terms, not academic terms that will put me in debt. I lack the mathematical chops necessary to calculate what's needed for circuitry and there is so much I don't know that it would be quite a long time before I'd be able to do anything. This is not to say that I don't want to learn - quite the contrary. But I do want to get my project off the ground in the coming months, not years, and I'm doing this alone.

 

[Deleted member 2947362]

Thank you for the very supportive words. I do appreciate it!
I have tried for months to find someone who could help me design and build what I need. I'm not in university as I am old and prefer to learn on my terms, not academic terms that will put me in debt. I lack the mathematical chops necessary to calculate what's needed for circuitry and there is so much I don't know that it would be quite a long time before I'd be able to do anything. This is not to say that I don't want to learn - quite the contrary. But I do want to get my project off the ground in the coming months, not years, and I'm doing this alone.

Yea I love learning new things that interest me, you sound similar to me with the aspect on how you learn.

I can't afford to be in debt or even want to be forced in to debt to learn something.

So I just had/have to teach myself and learned as much as I could/can from my own experiments, wacky idea's (which there has been many) and anything I can learn from others.

 

[Ralston18]

If you are on "your own terrms" then simply have at it.

Not a one-shot deal. May take a few tries.

Many tinkerer's have boxes and bins of salvage odds and ends. Easy to find discarded or cheap items to take apart for other uses. For little or no cost.

I have seen kids do all sorts of projects. Go online and look. Lots of DIY sites showing things that people have hacked for other purposes. Some safer than others so be careful....

Put something together. See what happens/results.

Break the problem into pieces. E.g., figure out a way to capture or contain an airflow.

Maybe a short section of plastic pipe or a soda bottle. Cardboard tube(s). Anything.

Then direct the airflow at a portable anemonmenter. Measure wind speeds or rpms.

Figuring that out may require additional step by step trial and error attempts.

No mathematics needed for tinkering around.

Don't let the perfect get in the way of what is good. Or good clean fun....

FYI: With a few pieces of scrap plastic you could make something like this to get a sense of air flows or speeds.

Wind speed indicator

 

[ReveurGAM]

If you are on "your own terrms" then simply have at it.

Not a one-shot deal. May take a few tries.

Many tinkerer's have boxes and bins of salvage odds and ends. Easy to find discarded or cheap items to take apart for other uses. For little or no cost.

I have seen kids do all sorts of projects. Go online and look. Lots of DIY sites showing things that people have hacked for other purposes. Some safer than others so be careful....

Put something together. See what happens/results.

Break the problem into pieces. E.g., figure out a way to capture or contain an airflow.

Maybe a short section of plastic pipe or a soda bottle. Cardboard tube(s). Anything.

Then direct the airflow at a portable anemonmenter. Measure wind speeds or rpms.

Figuring that out may require additional step by step trial and error attempts.

No mathematics needed for tinkering around.

Don't let the perfect get in the way of what is good. Or good clean fun....

FYI: With a few pieces of scrap plastic you could make something like this to get a sense of air flows or speeds.

Wind speed indicator

Thank you for the encouragement. I already made a wind tunnel - that was very easy to do and cost me very little I've got most of the parts I need to make a sound-dampening chamber for measuring fan noise already. The creation of circuits and complex devices is beyond my ability, though. I took two circuitry classes and learned that much.

It's a pity no one has been able to respond to my questions, though.

 

[Ralston18]

You are welcome.

However, you seem to have moved from fan wind speed measurement(s) to fan noise measurements.

No problem with you attempting to correlate the two.

Just have fun and enjoy your investigations. And what you learn in the process.

 

[ReveurGAM]

You are welcome.

However, you seem to have moved from fan wind speed measurement(s) to fan noise measurements.

No problem with you attempting to correlate the two.

Just have fun and enjoy your investigations. And what you learn in the process.

Oh, I was just sharing that I'm also doing that. 😉 once I get the right anemometer, I'll start making videos for my YT channel.

Thanks!