08-04-2020, 02:46 PM
Using the twin 140mm fans on the workbench aimed at my belly on a hot day..reveals the fake Delta to be the less effective fan, by a good margin. Even if I turn it up way higher than the BDS, its flow is not hitting my belly, but more like my neck and off to the sides.
Perhaps if this fake delta fan with the lesser angled longer forward jutting scythe like blades, were attached to blow into a restriction, like a busy finned heatsink, it would perform better in comparison, but in free unrestricted air the steeper more numerous blades of the BDS clone, are far more effective in velocity and column like flow.
The hubs steering vanes of the fake delta are also not angled as steeply. Everything about this fan says it is designed for high static pressure as opposed to high airflow, but even when I stick my hand closely in front of either fan at the same free airflow levels, the BDS fan seems less annoyed by the restriction. but this is far from an ideal static pressure test. and perhaps the BDS scavenging air right next to the fake delta is much more detrimental to the delta's flow than the other way around.
I think the fake delta's design would be good for my restrictive mushroom ceiling vent, but I am not going to make a 140 to ~102mm step down ring for it ,and the 120mm delta up there is very effective already, and much closer in blade design to the BDS.
Seems the fake delta threw a piece of balancing tape as well. It can achieve rather insane rpms. I have used a 5 K ohm 10 turn potentiometer on it and it is rather annoying to have to turn it 7 to 8 full turns to get it from minimum to maximum speed.
Need more potentiometers......
Perhaps if this fake delta fan with the lesser angled longer forward jutting scythe like blades, were attached to blow into a restriction, like a busy finned heatsink, it would perform better in comparison, but in free unrestricted air the steeper more numerous blades of the BDS clone, are far more effective in velocity and column like flow.
The hubs steering vanes of the fake delta are also not angled as steeply. Everything about this fan says it is designed for high static pressure as opposed to high airflow, but even when I stick my hand closely in front of either fan at the same free airflow levels, the BDS fan seems less annoyed by the restriction. but this is far from an ideal static pressure test. and perhaps the BDS scavenging air right next to the fake delta is much more detrimental to the delta's flow than the other way around.
I think the fake delta's design would be good for my restrictive mushroom ceiling vent, but I am not going to make a 140 to ~102mm step down ring for it ,and the 120mm delta up there is very effective already, and much closer in blade design to the BDS.
Seems the fake delta threw a piece of balancing tape as well. It can achieve rather insane rpms. I have used a 5 K ohm 10 turn potentiometer on it and it is rather annoying to have to turn it 7 to 8 full turns to get it from minimum to maximum speed.
Need more potentiometers......
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