New owner

[MAK Daddy]

Hi all, new pool owner. Always looking to learn and understand the way things work.
First question, is it more effective to heat the water with the pump on high speed or low speed?

 

[257WbyMag]

Welcome to TFP!

Interesting question. Not sure what would work better. We'll see what others have to say.

 

[ping]

With a heat pump, I would think the best speed will depend on the temperature of the air. If the temperature is marginally warm enough to run the heat pump, then I think running on slow speed would help to heat up the water and you would get a higher temperature gain, however, if the temperature is warm enough to get a 2+ degree raise on the outlet water while on high speed, I would think you will benefit most on high speed.

 

[MAK Daddy]

Thanks for the welcome.
It's fairly cool here in the PNW so I guess I will try both and see what happens.
The spa runs on high speed and heats pretty quickly at around an hour due to being much smaller amount of water, I could run a test there since it doesn't take long to heat up.
Right now the pool is getting rained on/in hope to get the cover installed next week.

 

[wjr75]

I have a bypass valve on my 400BTU heater that I keep at 45deg or 50% bypass. When it is fully closed letting all the water flow through the heater the hot tub doesn't heat as fast for some reason. I guess if the water is flowing to fast past the heat exchanger it doesn't have enough time to absorb the heat. Not sure where the excess heat goes...maybe up the top stack? I don't have a variable speed pump.

 

[MAK Daddy]

That's was my thinking as well, right now I have the pool on low speed for 8hrs and the hot tub on high speed for 2 hrs. I think low speed is .25HP, and it is super quite I have to look in the pump to see if it even running lol.