Electric Circuits: please look at this diagram...help! - Page 2

ECUPirate · 04-29-2002, 01:41 AM

my concern was this..
You can slow the low speed fans down quite a bit further than they already run. Could you slow the High speed ones down to the same RPMs that the low speed ones will reach?

Cyco-Dude · 04-29-2002, 08:29 AM

im sure you could. thats what baybuses and rheobuses are for

also, why would you want to slow a low-speed panaflow anyways? if you did, it would be practically useless, as it wouldnt be pushing any air really. also, they are already very quiet.

Brians256 · 04-29-2002, 10:48 AM

It's not that simple, cyco. The L1A is a low RPM fan that is designed to produce the maximum airflow at that speed. Taking an M1A and reducing the RPM will produce less airflow than the L1A and/or have more noise than the L1A. You are better off buying a fan that is designed for the target speed (unless you have a fan speed management system).

So, buy an M1A if you want to run it at the higher speed sometimes. Otherwise, just stick with the L1A if you are just going to undervolt the M1A.

The fan manufacturers use modeling software to design the fan blades for a targetted RPM. I trust them a lot more than me!

ECUPirate · 04-29-2002, 12:36 PM

thanks

Cyco-Dude · 04-29-2002, 01:23 PM

to brians: it depends on how much you lower the voltage :P
im just saying that it might be better to get the higher powered fan so that when you wanted more cfms, it would be there. but you're right; you should get the fan that bests suits your needs.

Brians256 · 04-29-2002, 03:27 PM

Cyco, I think we agree, then. I was just afraid that he'd be like many people out there who buy a 235CFM fan and then NEVER run it at full voltage! If you only want a maximum of 30CFM, buy a fan that is designed to move 30CFM. If you think you might want to move 235CFM sometime, don't be ashamed... go for the gusto! I know that pHaestus isn't ashamed of his 235CFM Rotron.

"More power Scotty!" - a man who likes pushing his hardware to the limit. Damn the warranties, full speed ahead!

ECUPirate · 04-29-2002, 09:51 PM

I've got a Rotron..

rated at 24V, but can only run at 12v...

Still, that's too loud for my purposes.

04-29-2002, 01:41 AM	#26
ECUPirate Hottest Stank of them All Join Date: Mar 2002 Location: Washington, DC area Posts: 533	my concern was this.. You can slow the low speed fans down quite a bit further than they already run. Could you slow the High speed ones down to the same RPMs that the low speed ones will reach? __________________ Does a radioactive cat have 18 half lifes? --Kenny my pimpin' rig: ...previously poorly cooled... 486DX-2 66mhz @ 75mhz, 4Mb ram, shared, 256Mb hard drive Onboard VGA, watercooled, of course 16-color monitor, labtec speakers, 28kbs USRobotics modem Windows XP (think about it) Maze 3, DDen GF3 block, Eheim 1250, econoline van HC, 1/2" hose w/ 5/8" fittings Comair 172mm fan

04-29-2002, 12:36 PM	#29
ECUPirate Hottest Stank of them All Join Date: Mar 2002 Location: Washington, DC area Posts: 533	thanks __________________ Does a radioactive cat have 18 half lifes? --Kenny my pimpin' rig: ...previously poorly cooled... 486DX-2 66mhz @ 75mhz, 4Mb ram, shared, 256Mb hard drive Onboard VGA, watercooled, of course 16-color monitor, labtec speakers, 28kbs USRobotics modem Windows XP (think about it) Maze 3, DDen GF3 block, Eheim 1250, econoline van HC, 1/2" hose w/ 5/8" fittings Comair 172mm fan

04-29-2002, 09:51 PM	#32
ECUPirate Hottest Stank of them All Join Date: Mar 2002 Location: Washington, DC area Posts: 533	I've got a Rotron.. rated at 24V, but can only run at 12v... Still, that's too loud for my purposes. __________________ Does a radioactive cat have 18 half lifes? --Kenny my pimpin' rig: ...previously poorly cooled... 486DX-2 66mhz @ 75mhz, 4Mb ram, shared, 256Mb hard drive Onboard VGA, watercooled, of course 16-color monitor, labtec speakers, 28kbs USRobotics modem Windows XP (think about it) Maze 3, DDen GF3 block, Eheim 1250, econoline van HC, 1/2" hose w/ 5/8" fittings Comair 172mm fan

04-29-2002, 08:29 AM	#27
Cyco-Dude Cooling Savant Join Date: Feb 2002 Location: Dayton, Ohio Posts: 836	im sure you could. thats what baybuses and rheobuses are for also, why would you want to slow a low-speed panaflow anyways? if you did, it would be practically useless, as it wouldnt be pushing any air really. also, they are already very quiet.

04-29-2002, 10:48 AM	#28
Brians256 Pro/Staff Join Date: Oct 2001 Location: Klamath Falls, OR Posts: 1,439	It's not that simple, cyco. The L1A is a low RPM fan that is designed to produce the maximum airflow at that speed. Taking an M1A and reducing the RPM will produce less airflow than the L1A and/or have more noise than the L1A. You are better off buying a fan that is designed for the target speed (unless you have a fan speed management system). So, buy an M1A if you want to run it at the higher speed sometimes. Otherwise, just stick with the L1A if you are just going to undervolt the M1A. The fan manufacturers use modeling software to design the fan blades for a targetted RPM. I trust them a lot more than me!

04-29-2002, 01:23 PM	#30
Cyco-Dude Cooling Savant Join Date: Feb 2002 Location: Dayton, Ohio Posts: 836	to brians: it depends on how much you lower the voltage :P im just saying that it might be better to get the higher powered fan so that when you wanted more cfms, it would be there. but you're right; you should get the fan that bests suits your needs.

04-29-2002, 03:27 PM	#31
Brians256 Pro/Staff Join Date: Oct 2001 Location: Klamath Falls, OR Posts: 1,439	Cyco, I think we agree, then. I was just afraid that he'd be like many people out there who buy a 235CFM fan and then NEVER run it at full voltage! If you only want a maximum of 30CFM, buy a fan that is designed to move 30CFM. If you think you might want to move 235CFM sometime, don't be ashamed... go for the gusto! I know that pHaestus isn't ashamed of his 235CFM Rotron. "More power Scotty!" - a man who likes pushing his hardware to the limit. Damn the warranties, full speed ahead!

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