Inexpensive but good quality fans

[RevGAM]

1 hour ago, Lurking said:

Most residential home HVAC systems in the US aren't really designed and perform poorly. Contractor just uses a 2-ton unit for a specific house size and runs 6"duct to each room. if the run is longer, you just get less flow in that room.  For larger homes they get a 3-ton unit...  Yes, they should get designed properly, but aren't. Use of flex duct is another mistake. I only design commercial systems and we use sophisticated controls and actual design etc. 

 

If you move 1 m^3/s at 1 Pa pressuredrop, you need 1W of air power. If we assume fan and motor efficiency multiply to 0.5, this means you need 2W electric power. It is a bit more complicated in IP units (and you learn quick why metric system is superior). "in-wc"is 1 inch of water column, which is one of the multiple IP units for pressure.  You can look up conversions, but all are pressure. mm-Hg is mm of mercury, psi= pounds/square-inch, psf- pound/squarefoot. You all can convert them to Pa or other units.  

 

Before worrying about fans, I'd optimize the case. If you don't have a case that allows good flow and large fans, all the time and money spent on fans is kind of wasted. I stumbled across this thread because I considered upgrading fans in my Fractal R5 case, which actually is a relatively well ventilated case compared to some of the abominations of cases. But it has 4 intake fans and one exhaust fan (assuming i don't use the top fan locations). So 5 good 140mm fans... Even if i just get the cheap Arctic fans, that would have been $50, or over $100 for Noctua or over $150 for Bequiet fans. It sure would have helped a bit. But I ultimately decided to get an airflow case with large fans. One option was the Lancool 216 with 160mm fans for $100. I needed up with a $90 used Torrent Compact with 180mm fans and now have a superior and cheaper solution (better cooling at low noise) compared to buying new fancy fans. and I now have the (still OK) R5 for other uses. What I'm trying to say is, before finding the best fan for a bad case, get a better case (and if it comes with good fans, it is a bargain). 

 

I hope this large fan (i.e. 180mm) idea is catching on and the next step is to get rid of the small 120/140mm fans the same way we got rid of 80 mm fans. It is just simple physics that larger fans are more efficient and larger cross sectional areas (filters etc.) allow much less pressure drop at a given flowrate if the larger fans are used. There is just no magic you can apply to a 120 or 140mm fan that will make it as good as a 180mm fan. Large fan airflow cases are modern Dreadnoughts and made every small fan case obsolete at once.  

Very interesting - I had to concentrate hard to make sure I followed it correctly LOL! Math and I...sigh. So, if I'm looking at a home (or, worse, I'm working with Habitat for Humanity to build one), can you give me any tips for ductwork best practices?

Apparently, the standard used to measure fan AF is CMM and SP is mmH2O or mmAq.

 

Thanks for the tip on the case. I would need to get a cheap, large case with no sharp edges (since I'm constantly inside it switching fans around and such) as my Corsair iCUE 5000x RGB doesn't support larger than 140mm and I'm not particularly impressed with the airflow (although it's not even close to the really bad cases). If you have any suggestions in that regard, let me know.

I do intend to test 140mm fans, and I already have a couple but, for larger fans, I'm going to need to find the same material but in a larger diameter as 8" can't accommodate anything bigger without making a reducer that would cause different results than my current tunnel. However, my goal is to start with low-cost fans (because I have no financial support and can only work part-time right now) in order to identify ones that outperform the expensive ones but are relatively unknown, kinda like how the Arctic P12/Max has become famous. The only catch there is that some of the cheapest fans come with a very large shipping cost because they're usually from China, so that automatically puts them in the same price range as the famous stuff (e.g. one cost $1.99 but S&H was $24).

 

I think that there will be a limit to large fans catching on because a lot of people don't want a large footprint, and some want tiny cases, but I agree with you. Bigger is better, she said. Oh, wait, wrong forum.  LOL!

I'll bet David Copperfield, Kris Angel, Chris Ramsey and other magicians could make it seem like a small fan is much better than it really is.  

 

Thanks for your continuing input!

 

 

 

 

[Lurking]

3 minutes ago, RevGAM said:

Very interesting - I had to concentrate hard to make sure I followed it correctly LOL! Math and I...sigh. So, if I'm looking at a home (or, worse, I'm working with Habitat for Humanity to build one), can you give me any tips for ductwork best practices?

Apparently, the standard used to measure fan AF is CMM and SP is mmH2O or mmAq.

 

Thanks for the tip on the case. I would need to get a cheap, large case with no sharp edges (since I'm constantly inside it switching fans around and such) as my Corsair iCUE 5000x RGB doesn't support larger than 140mm and I'm not particularly impressed with the airflow (although it's not even close to the really bad cases). If you have any suggestions in that regard, let me know.

I do intend to test 140mm fans, and I already have a couple but, for larger fans, I'm going to need to find the same material but in a larger diameter as 8" can't accommodate anything bigger without making a reducer that would cause different results than my current tunnel. However, my goal is to start with low-cost fans (because I have no financial support and can only work part-time right now) in order to identify ones that outperform the expensive ones but are relatively unknown, kinda like how the Arctic P12/Max has become famous. The only catch there is that some of the cheapest fans come with a very large shipping cost because they're usually from China, so that automatically puts them in the same price range as the famous stuff (e.g. one cost $1.99 but S&H was $24).

 

I think that there will be a limit to large fans catching on because a lot of people don't want a large footprint, and some want tiny cases, but I agree with you. Bigger is better, she said. Oh, wait, wrong forum.  LOL!

I'll bet David Copperfield, Kris Angel, Chris Ramsey and other magicians could make it seem like a small fan is much better than it really is.  

 

Thanks for your continuing input!

 

 

 

 

I'm not aware of cases for ATX PSU that would not be wide enough for 180mm fans. If a 120mm tower cooler fits in, a 180mm fan shouldn't be impossible. 

 

I don't think any brand case has sharp edges. and if you have a good case, no need to swap fans around all the time. Teh 2 cases i mentioned basically have th eoptimum already set up. No need to tinker. 

 

One hint for HVAC, make sure ducts are sealed and NOT in unconditioned space (i.e. crawl space or attic). Lots of air loss through duct. Air loss (supply) or gain (return duct) will cause huge imbalances int he house and increase infiltration/exfiltration. Larger duct = better duct, especially on the longer runs. but in a single-zone system (likemost homes), you will have to compromise for heating/cooling. 

[RevGAM]

30 minutes ago, Lurking said:

I'm not aware of cases for ATX PSU that would not be wide enough for 180mm fans. If a 120mm tower cooler fits in, a 180mm fan shouldn't be impossible. 

My case isn't, unless the screw holes on larger fans are positioned to match the 105mm spacing of a 120mm, or 124.5mm of a 140mm fan. And there are many other cases that have the same issue, not to mention not having enough width.

30 minutes ago, Lurking said:

I don't think any brand case has sharp edges. and if you have a good case, no need to swap fans around all the time. Teh 2 cases i mentioned basically have th eoptimum already set up. No need to tinker. 

There are cheap brands where the manufacturer doesn't bother to smooth sharp edges or fold them over. I recall Linus being cut in at least one of his videos.

30 minutes ago, Lurking said:

One hint for HVAC, make sure ducts are sealed and NOT in unconditioned space (i.e. crawl space or attic). Lots of air loss through duct. Air loss (supply) or gain (return duct) will cause huge imbalances int he house and increase infiltration/exfiltration. Larger duct = better duct, especially on the longer runs. but in a single-zone system (likemost homes), you will have to compromise for heating/cooling. 

Sealed with what? By unconditioned, do you mean no insulation? Would it be good to wrap duct in insulation? How large is ideal in a home? Why do you say most homes are single-zone? I probably would not get AC - I save hundreds of dollars a month by not using AC and keeping my thermostat at 60 F in the winter.  I think I pay $50-70/mo cuz I'm frugal.

[Lurking]

15 minutes ago, RevGAM said:

My case isn't, unless the screw holes on larger fans are positioned to match the 105mm spacing of a 120mm, or 124.5mm of a 140mm fan. And there are many other cases that have the same issue, not to mention not having enough width.

There are cheap brands where the manufacturer doesn't bother to smooth sharp edges or fold them over. I recall Linus being cut in at least one of his videos.

Sealed with what? By unconditioned, do you mean no insulation? Would it be good to wrap duct in insulation? How large is ideal in a home? Why do you say most homes are single-zone? I probably would not get AC - I save hundreds of dollars a month by not using AC and keeping my thermostat at 60 F in the winter.  I think I pay $50-70/mo cuz I'm frugal.

Duct Sealant and tape.

 

I meant there is physical space for 180mm fans if the case is wide enough for a 120mm tower. Such case would be 200mm or wider. Obviously they need to re-design the front. So I'm talking about new cases. but you sure can dremel around and retro-fit an older case. 

 

Just look at the Fractal torrent, very simple and straigth forward design. No fuzz and no difficulty. All open in front with filter, then 2 large fans and all the back wide open. Simple and efficient. Just use as it comes from the factory and you never have to worry if other fan locations may be better or worse. It just works very well. 

 

[Likwid]

On 3/31/2023 at 2:42 AM, RONOTHAN## said:

The Arctic P12 are generally the go to recommendation for this, they're $30 for a pack of 5 with pretty good performance. 

Just ordered a pack

[RevGAM]

1 hour ago, Likwid said:

Just ordered a pack

They're nice, but the P12 Max is better. Either way, it's a good deal.

[Dogzilla07]

8 hours ago, Lurking said:

I hope this large fan (i.e. 180mm) idea is catching on and the next step is to get rid of the small 120/140mm fans the same way we got rid of 80 mm fans. It is just simple physics that larger fans are more efficient and larger cross sectional areas (filters etc.) allow much less pressure drop at a given flowrate if the larger fans are used. There is just no magic you can apply to a 120 or 140mm fan that will make it as good as a 180mm fan.

The problem is how thick they need to be. fans are generally too thin. the Fractal 180 works good cause it's 38mm (still not very good on noise and stuff), a 180/200/230mm fan that's only 25mm has been shown to be anemic as hell and destroyed by 140x25mm fans, and 120x30mm phanteks T30-120.

 

95% of 140x25mm fans also get beat by the top 3 120x25/x30mm fans.

Going larger in x+y axis might be ok in open bench, but it does nothing vs filters/radiators/mesh/air coolers, the static pressure is just not there, u need to go bigger in the z-axis as well, or your noise-normalized performance break apart.

 

Cases are only now starting to get optimized for 30mm thick fans, and only for 120, Phanteks released a basically 120mm only case NV7, and Hyte is also looking at releasing a 120mm only case

[Lurking]

1 hour ago, Dogzilla07 said:

The problem is how thick they need to be. fans are generally too thin. the Fractal 180 works good cause it's 38mm (still not very good on noise and stuff), a 180/200/230mm fan that's only 25mm has been shown to be anemic as hell and destroyed by 140x25mm fans, and 120x30mm phanteks T30-120.

 

95% of 140x25mm fans also get beat by the top 3 120x25/x30mm fans.

Going larger in x+y axis might be ok in open bench, but it does nothing vs filters/radiators/mesh/air coolers, the static pressure is just not there, u need to go bigger in the z-axis as well, or your noise-normalized performance break apart.

 

Cases are only now starting to get optimized for 30mm thick fans, and only for 120, Phanteks released a basically 120mm only case NV7, and Hyte is also looking at releasing a 120mm only case

According to GN noise normalized test the Lancool 216 and the Torrents are beating the hell out of the other cases. 

 

My Torrent fans are silent at very noticeable airflow. This isn't scientific, but I'm pretty noise sensitive. I've seen several tests that the Torrent at low speed performs almost as excellent as at full speed. 

 

I'n sure 180mm fans also can be improved. But they inherently already are good and this is a step in the right direction 

[thrasher_565]

4 hours ago, Lurking said:

According to GN noise normalized test the Lancool 216 and the Torrents are beating the hell out of the other cases. 

 

My Torrent fans are silent at very noticeable airflow. This isn't scientific, but I'm pretty noise sensitive. I've seen several tests that the Torrent at low speed performs almost as excellent as at full speed. 

 

I'n sure 180mm fans also can be improved. But they inherently already are good and this is a step in the right direction 

the torrent is a really good air flow case. lancool is also good. all good cases form lian li (exspet the evo... stay away form that one)

[Dogzilla07]

8 hours ago, Lurking said:

But they inherently already are good and this is a step in the right direction 

Because they're fat, the only reason Silverstone 180mm did good is cause they're fat, Z-axis width makes or breaks fans (You need to stay close to the golden ratio)

[RevGAM]

7 hours ago, thrasher_565 said:

the torrent is a really good air flow case. lancool is also good. all good cases form lian li (exspet the evo... stay away form that one)

What's wrong with that?

3 hours ago, Dogzilla07 said:

Because they're fat, the only reason Silverstone 180mm did good is cause they're fat, Z-axis width makes or breaks fans (You need to stay close to the golden ratio)

Yeah, unless you can figure out the magic secret to making a slim fan perform like a wide one. Ask Kris Angel. 

[RevGAM]

@thrasher_565 @Lurking @Dogzilla07

I have a question. I'm not so good at math, but I'm trying to devise a formula to produce a weighted average (WA) of fans based on how well the top 5 did.
I'm not sure if the formula is correct, so I'm changing it, but I'd like your thoughts on the relative value (RV) of each of: CPU, Mobo, VRM Thermistor, GC, M+V+G, and All. 1 is the most and 10 is the least important in reference to CPU coolers. Obviously, CPU gets a 1 since that's what the coolers are for, and I think maybe mobo should be 10 because it's pretty difficult for a cooler to cool off an entire mobo.

My thought is that I should take the rank of the fan in each of those 5 categories times the weighted value of that category, add all the top 5s for a fan together and divide by 5.
Here's an example of the chart with possible RVs (no GC here because BIOS doesn't show that value):
 
Take for example fan LM RM. Would this formula make sense? The result should be that the lower the WA, the better the fan is (i.e. a WA of 7 is better than 20). As you can see, there were some ties.

WA=((RCPU*RV)+(RMobo*RV)+(RVRM*RV)+(RM&V*RV)+(RAll*RV))ER/TP
WA=((5*RV)+(4*RV)+(2*RV)+(2*RV)+(3*RV))/5/5

 

WA: Weighted Average

RV: Relative Value of cooling that part

R: Ranked result in top 5 (0 if there's no rank in a category)
ER: # of Earned Ranks

TP: Total Possible Ranks (always 5 in this example)
 

Is my formula correct? If not, what should it be?

Thanks!

[thrasher_565]

7 minutes ago, RevGAM said:

@thrasher_565 @Lurking @Dogzilla07

I have a question. I'm not so good at math, but I'm trying to devise a formula to produce a weighted average (WA) of fans based on how well the top 5 did.
I'm not sure if the formula is correct, so I'm changing it, but I'd like your thoughts on the relative value (RV) of each of: CPU, Mobo, VRM Thermistor, GC, M+V+G, and All. 1 is the most and 10 is the least important in reference to CPU coolers. Obviously, CPU gets a 1 since that's what the coolers are for, and I think maybe mobo should be 10 because it's pretty difficult for a cooler to cool off an entire mobo.

My thought is that I should take the rank of the fan in each of those 5 categories times the weighted value of that category, add all the top 5s for a fan together and divide by 5.
Here's an example of the chart with possible RVs (no GC here because BIOS doesn't show that value):
 
Take for example fan LM RM. Would this formula make sense? The result should be that the lower the WA, the better the fan is (i.e. a WA of 7 is better than 20). As you can see, there were some ties.

WA=((RCPU*RV)+(RMobo*RV)+(RVRM*RV)+(RM&V*RV)+(RAll*RV))ER/TP
WA=((5*RV)+(4*RV)+(2*RV)+(2*RV)+(3*RV))/5/5

 

WA: Weighted Average

RV: Relative Value

R: Ranked result in top 5 (0 if there's no rank in a category)
ER: # of Earned Ranks

TP: Total Possible Ranks (always 5 in this example)
 

Is my formula correct? If not, what should it be?

Thanks!

im bad at math im out...

i dont under stand it at all... is this a point system?

 

2 hours ago, RevGAM said:

What's wrong with that?

Yeah, unless you can figure out the magic secret to making a slim fan perform like a wide one. Ask Kris Angel. 

the biggerr the fan the thiccer it has to be do to needing thicker blades. at lest ones that expect to stay to gather that is...

 

2 hours ago, RevGAM said:

 

What's wrong with that?

nothing. just saying its a really good case destined around air cooling.

[RevGAM]

34 minutes ago, thrasher_565 said:

3 hours ago, RevGAM said:

What's wrong with that?

nothing. just saying its a really good case destined around air cooling.

I meant the evo, which you said:

3 hours ago, RevGAM said:

10 hours ago, thrasher_565 said:

the torrent is a really good air flow case. lancool is also good. all good cases form lian li (exspet the evo... stay away form that one)

 

37 minutes ago, thrasher_565 said:

im bad at math im out...

i dont under stand it at all... is this a point system?

No worries.

Yes.

[Lurking]

8 hours ago, Dogzilla07 said:

Because they're fat, the only reason Silverstone 180mm did good is cause they're fat, Z-axis width makes or breaks fans (You need to stay close to the golden ratio)

I'm not a fan designer. But I suspect you want to keep the dimensions in some proportion. 

Number of blades, shape (inc. thickness) are other factors. 

 

So yes, a 180 mm fan would be thicker than a 120mm fan. 

 

You probably are onto something since the T30 as one of the best fans is thicker. So Fractal did fine with 38mm.

 

But still, larger fan runs at lower speed. This doesn't matter in PCs, but larger fans alo use significantly less power. I select them for HVAC and the larger fan of the same fan family often uses half or even less power than smaller faster fans. Like 7 horsepower vs. 3hp.

 

A larger fan by a filter also reduces filter pressuredrop at a given flowrate. Larger are = lower velocity. And velocity and pressure drop are in a square relationship. So at half the speed, only quarter of the pressure dro though the filter.

 

So we have 2 inherent advantages for large fans mounted against a filter. You can't cheat Physics.

[RevGAM]

47 minutes ago, Lurking said:

I'm not a fan designer. But I suspect you want to keep the dimensions in some proportion. 

Number of blades, shape (inc. thickness) are other factors. 

 

So yes, a 180 mm fan would be thicker than a 120mm fan. 

 

You probably are onto something since the T30 as one of the best fans is thicker. So Fractal did fine with 38mm.

 

But still, larger fan runs at lower speed. This doesn't matter in PCs, but larger fans alo use significantly less power. I select them for HVAC and the larger fan of the same fan family often uses half or even less power than smaller faster fans. Like 7 horsepower vs. 3hp.

 

A larger fan by a filter also reduces filter pressuredrop at a given flowrate. Larger are = lower velocity. And velocity and pressure drop are in a square relationship. So at half the speed, only quarter of the pressure dro though the filter.

 

So we have 2 inherent advantages for large fans mounted against a filter. You can't cheat Physics.

Is my formula correct?

[RevGAM]

Sigh. I received the replacement ProtMex anemometer. As soon as I started testing it, I could hear the vanes rubbing against something, slowing them down significantly. The only way to prevent that is to hold it parallel to the ground or leaning forward (screenwards). Sigh. 

[RevGAM]

@LurkingAre any of these a good manometer for SP?
Triplett DPR302 Handheld Differential Pressure Manometer, 2 psi
Triplett DPR305 Handheld Differential Pressure Manometer, 5 psi
https://www.amazon.com/Dwyer-Handheld-Manometer-Intrinsically-Approved/dp/B009PAFJPM?th=1 (reviews suggest some are not good quality, but there are 10 other models listed, too, so maybe one of the models would be appropriate but I don't understand them)

Can you tell me which brands for anemometers and manometers are reputable?

[thrasher_565]

9 hours ago, RevGAM said:

I meant the evo, which you said:

 

No worries.

Yes.

the evo is poor qulatiy. the fan brackets are flimsy. dont lock it all that easy. and also one fan scrapes it as its bent. the front mesh thing is also flimsy. well you can mount 140mm fans on the bottom that dam close to the mb... so close it bends the cables. and the thing that takes the cake is the reset/power/ led being in one connector so if you dont have a mb that it fits sol.

could have been a good case but didn't... maybe they did a recall or maybe they send out people cables on request i dont no.

 

 

Edited April 17, 2023 by thrasher_565

[Lurking]

6 hours ago, RevGAM said:

Sigh. I received the replacement ProtMex anemometer. As soon as I started testing it, I could hear the vanes rubbing against something, slowing them down significantly. The only way to prevent that is to hold it parallel to the ground or leaning forward (screenwards). Sigh. 

Did it come with a calibration certificate? This at minimum is a faulty unit, if it isn't just a cheap and badly designed one. You probably could watch a feather flying and come up with a better estimate. Send that thing back. 

1 hour ago, RevGAM said:

@LurkingAre any of these a good manometer for SP?
Triplett DPR302 Handheld Differential Pressure Manometer, 2 psi
Triplett DPR305 Handheld Differential Pressure Manometer, 5 psi
https://www.amazon.com/Dwyer-Handheld-Manometer-Intrinsically-Approved/dp/B009PAFJPM?th=1 (reviews suggest some are not good quality, but there are 10 other models listed, too, so maybe one of the models would be appropriate but I don't understand them)

Can you tell me which brands for anemometers and manometers are reputable?

PC fans create pressure to 2-3 or or even fewer mm-H2O. So you need a gauge with maybe 5mm H2O. The one listed has range of 2 psi. That is 1406 mm H2O. it says it is accurate +/- 0.3% of full scale. Atlest thye make it clear that the % is for full scale. Some people think a % error is based on the read value. Like if you measure 10psi, then 10% error would be +/1 1 psi. But it always is based on full scale. So if you have a 100 psi gauge with +/- 5%, this means every value could be +/- 5 psi. So if you measure 10psi, the real value could be 5 or 15 psi. So you don't want a gauge with an extremely large scale compared to the expected value. Electronic gauges can adjust for that a bit, but that isn't the case for cheap ones!

 

Some good instruments even detail the accuracy for the range you are in. This is just an example of a good tire gauge and they list the ASME it is under and the accuracy in the range. You see in many cases the accuracy in the middle of the scale is highest. This one also states it measures starting at 5%. So it isn't supposed to measure below 5% of full scale. An instrument you pick, should provide similar information. 

 

That would be +/- 4.2 mmH2O. It may also have a minimum pressure it  measures, but doesn't list it. But you see the problem using this when the pressure you expect is just a few mm H2O. You also don't know if what they say is correct since it doesn't say it mees ASME or ASTM for pressure gauges. I don't know that manufacturer, but a useful device would provide information to what standard they comply and provide a calibration certificate. 

 

It will be hard to find equipment for PC fans since the values you measure are so tiny compared to typical equipment. Fans you use in your home HVAC might be in the 2-4 inH2) (multiply by 25.4 to get mm H2O) range. So as a rule of thumb, the PC fan pressure only is a 25th of what you expect in a home. Very hard to measure. 

8 hours ago, RevGAM said:

Is my formula correct?

Which formula specifically? Sorry, I got lost.... 

[RevGAM]

6 hours ago, Lurking said:

Did it come with a calibration certificate? This at minimum is a faulty unit, if it isn't just a cheap and badly designed one. You probably could watch a feather flying and come up with a better estimate. Send that thing back. 

PC fans create pressure to 2-3 or or even fewer mm-H2O. So you need a gauge with maybe 5mm H2O. The one listed has range of 2 psi. That is 1406 mm H2O. it says it is accurate +/- 0.3% of full scale. Atlest thye make it clear that the % is for full scale. Some people think a % error is based on the read value. Like if you measure 10psi, then 10% error would be +/1 1 psi. But it always is based on full scale. So if you have a 100 psi gauge with +/- 5%, this means every value could be +/- 5 psi. So if you measure 10psi, the real value could be 5 or 15 psi. So you don't want a gauge with an extremely large scale compared to the expected value. Electronic gauges can adjust for that a bit, but that isn't the case for cheap ones!

 

Some good instruments even detail the accuracy for the range you are in. This is just an example of a good tire gauge and they list the ASME it is under and the accuracy in the range. You see in many cases the accuracy in the middle of the scale is highest. This one also states it measures starting at 5%. So it isn't supposed to measure below 5% of full scale. An instrument you pick, should provide similar information. 

 

 

That would be +/- 4.2 mmH2O. It may also have a minimum pressure it  measures, but doesn't list it. But you see the problem using this when the pressure you expect is just a few mm H2O. You also don't know if what they say is correct since it doesn't say it mees ASME or ASTM for pressure gauges. I don't know that manufacturer, but a useful device would provide information to what standard they comply and provide a calibration certificate. 

 

It will be hard to find equipment for PC fans since the values you measure are so tiny compared to typical equipment. Fans you use in your home HVAC might be in the 2-4 inH2) (multiply by 25.4 to get mm H2O) range. So as a rule of thumb, the PC fan pressure only is a 25th of what you expect in a home. Very hard to measure. 

Which formula specifically? Sorry, I got lost.... 

Thanks very much for the info - so getting one with even a very low psi of .5 is going to be a bad choice. Got it.

 

The formula is in the post above with the graph. I'm pretty sure it's wrong but I can't figure out what's wrong, and I'm not sure what values to assign for the weighting.

I am considering either a mini-vane (16mm) like the Testo I mentioned before, or a hotwire, but now I wonder if a hotwire might have a problem with low flow, too? What are your thoughts?

[RevGAM]

@LurkingCan you tell me what you think of Extech, Bonvoisin, Reed Instruments, and Koselig Instruments?

[RevGAM]

I was wondering if anyone thinks it's worthwhile to review sub-120mm fans? I accidentally bought a 92mm Zalman, and I'm really not sure if I should waste money on small fans.

[thrasher_565]

3 hours ago, RevGAM said:

I was wondering if anyone thinks it's worthwhile to review sub-120mm fans? I accidentally bought a 92mm Zalman, and I'm really not sure if I should waste money on small fans.

nop no one use em.

unless your me. i got argb 80mm fans and 92mm fans...

Edited May 5, 2023 by thrasher_565

[Deadpool2onBlu-Ray]

On 3/30/2023 at 6:38 PM, RevGAM said:

Please recommend low-cost fans to me, especially if you have seen few (or no) data-driven reviews about them. Any size that is typical for PCs (120-200mm?). No server fans, and no known POS fans, please.

Inexpensive/Good quality are kind of an oxymoron for case fans. I guess the Arctic P12 are decent. You really want T30s or A12s though