Everybody is always talking about fans pulling air through filters and pushing air through rads. I have a bunch of fans around here. I decided I would measure their output first naked, then pulling air through filters then pushing air through a rad.
By juxtaposing the Slip Streams vs the Gentle Typhoons, I was pitting the quintessential high-CFM-low-static-pressure SS's vs fans that were just the opposite - GT's. I added the San Aces as a bonus.
Setup
I have the complete line of Slip Stream fans that I bought at retail 2010-2011. I have pairs of each speed, from 500 RPM to 1900 RPM. I also have the complete line of Scythe Gentle Typhoons in pairs or more from 500-1850 RPM. I also have four 2150 RPM GT's from the late group by we did at OCN, and single specimens of the 300 and 4250 RPM GT's. I have pairs or more of the San Ace "Silent" line running from 1500 to 2700 RPM, and selected 120x38mm San Ace fans. I tested them all.
For noise, I put each fan on a test stand and measured the free air RPM and Sound Pressure Level at 10cm from the intake. When you subtract 20dB from that, you get the theoretical equivalent SPL at 1m. Understand that my basement is silent - but silent to a human ear is around 30 dB SPL. My basement was 31 dBA (31 dB in "A" weighting - closest to what humans hear), so a 34-dBA fan was an extremely quiet fan. A 34-dBA fan is represented at 14 dBA in the chart: measured SPL minus 20 dB.
I used an Extech AN100 anemometer to measure the output in Cubic Feet per Minute. The test box was 12 x 8.5 x 18 inches. I used a wire mesh for the filter, and half of a GT Stealth 120 x 240 x 30mm rad. The radiator is 30 fins per inch, so it was a mighty test of a fan's pushing power.
In the charts following, you will see first the spec, then then average of however many fans I had of each model, x2 for two, x4 for 4, etc. Then come the results for the individual fans. I did that so you can see how fans vary within each model. For the unfiltered, non-rad output I left a single digit open so you can see that some fans are not quite identical.
On each line, a fan is represented by its model number, its RPM, its SPL (in dBA), its flow through the rad, its flow through the filter, and the unobstructed flow - all in CFM.
There are five total posts in this series. Please refrain from commenting until after #5
By juxtaposing the Slip Streams vs the Gentle Typhoons, I was pitting the quintessential high-CFM-low-static-pressure SS's vs fans that were just the opposite - GT's. I added the San Aces as a bonus.
Setup
I have the complete line of Slip Stream fans that I bought at retail 2010-2011. I have pairs of each speed, from 500 RPM to 1900 RPM. I also have the complete line of Scythe Gentle Typhoons in pairs or more from 500-1850 RPM. I also have four 2150 RPM GT's from the late group by we did at OCN, and single specimens of the 300 and 4250 RPM GT's. I have pairs or more of the San Ace "Silent" line running from 1500 to 2700 RPM, and selected 120x38mm San Ace fans. I tested them all.
For noise, I put each fan on a test stand and measured the free air RPM and Sound Pressure Level at 10cm from the intake. When you subtract 20dB from that, you get the theoretical equivalent SPL at 1m. Understand that my basement is silent - but silent to a human ear is around 30 dB SPL. My basement was 31 dBA (31 dB in "A" weighting - closest to what humans hear), so a 34-dBA fan was an extremely quiet fan. A 34-dBA fan is represented at 14 dBA in the chart: measured SPL minus 20 dB.
I used an Extech AN100 anemometer to measure the output in Cubic Feet per Minute. The test box was 12 x 8.5 x 18 inches. I used a wire mesh for the filter, and half of a GT Stealth 120 x 240 x 30mm rad. The radiator is 30 fins per inch, so it was a mighty test of a fan's pushing power.
In the charts following, you will see first the spec, then then average of however many fans I had of each model, x2 for two, x4 for 4, etc. Then come the results for the individual fans. I did that so you can see how fans vary within each model. For the unfiltered, non-rad output I left a single digit open so you can see that some fans are not quite identical.
On each line, a fan is represented by its model number, its RPM, its SPL (in dBA), its flow through the rad, its flow through the filter, and the unobstructed flow - all in CFM.
There are five total posts in this series. Please refrain from commenting until after #5