Optimum pump speed when using heater

[jgarden]

Are there any conclusive studies that have been done with regards to optimum speed to run a variable speed pump when trying to heat a pool or spa? If you know of any please post the link.

Slower water through the heater should achieve a higher delta. However, I have no idea if that increase translates into higher efficiency or ultimately quicker heating of the spa or pool.

I found this ARTICLE but it is unclear if they did any actual scientific testing.

 

[mknauss]

Other than satisfying the pressure switch to allow the heater to run, there is no appreciable difference in time to heat your body of water. Too high a rate will most likely cause the heater to go into bypass.

 

[jgarden]

Found another ARTICLE that says the faster speed is better. This article deals with solar, but the theory should be similar.

 

[jgarden]

Other than satisfying the pressure switch to allow the heater to run, there is no appreciable difference in time to heat your body of water. Too high a rate will most likely cause the heater to go into bypass.

I have run my heater with Ecostar pump on full speed, and I haven't seen a bypass problem. I am also running a 500k BTU heater.

I am no scientist, but I have to think there is some optimum speed where one achieves max efficiency of the heater and the motor.

@chem geek has a good discussion about this regarding solar over HERE.