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Cathar · 11-16-2003, 07:35 AM

While it varies depending on model, I think that it would be generally fair to say that a blower will produce the same air-flow through a restrictive (radiator) system with less noise and less power than an axial fan that gave the same system air-flow.

The main reason why blowers are not used is because of their size. They are just plain bulky. Where an axial fan is basically 2 dimensional, with the 3rd dimenion being maybe 1/4-1/3 of the size of the other two dimenions (eg. a 120x120x38mm axial fan), a blower that has the sort of properties we're talking about would at least be around 120x120x120mm in size, if not a bit bigger.

Blowers have nice low voltage properties. Yes, many blowers at full speed will be quite noisy, but you can run them at quarter voltage for maybe 1/8th the noise, and still be getting better air-flow than an axial fan.

The blower I have will run all the way down to 4V/low speed setting, at which stage it's drawing about 6W of power and is very weak. I typically run it at 7C/low speed, and it draws ~20W of power and pushes out about as much air through my radiators, as a 80CFM fan does in free air (no load), and is about half as noisy as then 80CFM fan would be.

It can also run all the way up to 15V/18A (~270W) and the amount of air and pressure it pushes here is simply staggering, but the noise, while definitely loud, isn't that annoying, and definitely easier to live with than a 7K RPM 60mm Delta, or 6K RPM 80mm Delta. Imagine your car heater fan running at full blast, since that's exactly where my blower comes from. Loud rushing air, but no whining or droning.

As to "what works best?", well this is a fairly new area for computer water cooling systems. I tell you what though, the heater-cores that we've been grabbing and using for our water-cooling radiators all came from cars that had blowers sitting behind them to push air through them. i.e. the car industry has already done the math and worked out what works best.

When people are looking for a cheap radiator by going to a wreckers and ripping out a heater-core, they would do very well to go the extra step and grab the blower behind the heater-core while they're at it, since that's the thing that was purpose built to push the air through the heater-core that they're grabbing, and it runs on 12V to boot.

11-16-2003, 07:35 AM	#17
Cathar Thermophile Join Date: Sep 2002 Location: Melbourne, Australia Posts: 2,538	While it varies depending on model, I think that it would be generally fair to say that a blower will produce the same air-flow through a restrictive (radiator) system with less noise and less power than an axial fan that gave the same system air-flow. The main reason why blowers are not used is because of their size. They are just plain bulky. Where an axial fan is basically 2 dimensional, with the 3rd dimenion being maybe 1/4-1/3 of the size of the other two dimenions (eg. a 120x120x38mm axial fan), a blower that has the sort of properties we're talking about would at least be around 120x120x120mm in size, if not a bit bigger. Blowers have nice low voltage properties. Yes, many blowers at full speed will be quite noisy, but you can run them at quarter voltage for maybe 1/8th the noise, and still be getting better air-flow than an axial fan. The blower I have will run all the way down to 4V/low speed setting, at which stage it's drawing about 6W of power and is very weak. I typically run it at 7C/low speed, and it draws ~20W of power and pushes out about as much air through my radiators, as a 80CFM fan does in free air (no load), and is about half as noisy as then 80CFM fan would be. It can also run all the way up to 15V/18A (~270W) and the amount of air and pressure it pushes here is simply staggering, but the noise, while definitely loud, isn't that annoying, and definitely easier to live with than a 7K RPM 60mm Delta, or 6K RPM 80mm Delta. Imagine your car heater fan running at full blast, since that's exactly where my blower comes from. Loud rushing air, but no whining or droning. As to "what works best?", well this is a fairly new area for computer water cooling systems. I tell you what though, the heater-cores that we've been grabbing and using for our water-cooling radiators all came from cars that had blowers sitting behind them to push air through them. i.e. the car industry has already done the math and worked out what works best. When people are looking for a cheap radiator by going to a wreckers and ripping out a heater-core, they would do very well to go the extra step and grab the blower behind the heater-core while they're at it, since that's the thing that was purpose built to push the air through the heater-core that they're grabbing, and it runs on 12V to boot.