Variable speed question from a single speed owner...

[MattMoore]

Do variable speed pump owners run their pump at slow speeds with a flow rate high enough to trip the heater?

I am considering moving to a variable speed pump but also have a Jandy heater which requires 30gpm to actuate.


My "time of use" electricity rates in Ontario are considerably higher through the day and running at a speed below the heater speed would be ideal and get the filter changeover through night. I understand you can set your timer to do this but the pool would cool off through the day. I know automation could control this but most options seem cost prohibitive.

 

[Rancho Cost-a-Lotta]

I have an IntelliFlo VS pump that trips my heater around 1,400 rpm. At 1,500 rpm, my pumps pulls just over 200 watts. By comparison, a 1 hp pump probably draws close to 1,000 watts. I run my pump mostly at 1,800 rpms (about 360 watts) and a couple hours at 2,400 rpm (about 850 watts). Here are a couple pics of my pump display to give you an idea of how rpm's effect energy consumption.



Here is a chart that demonstrates the correlation between pump speeds and energy consumption (3 hp pump).

 

[MattMoore]

Thanks for that!

I used a high end clamp meter last night and tested the draw on my single speed super pump. 14.6amps at 123v.; calculated 1796watts!

My daytime energy costs are 17c/kw so it adds up fast.

6hrs @17c/kw, 6hrs at 11.3c/kw and 12hrs at 8.2c/kw.

 

[Jimrahbe]

get the filter changeover through night.

Matt,

Just so that we are all on the same page... I suspect that the "changeover" you are talking about is the idea that you have to "turnover" x amount of water per day to prevent the pool from getting algae. If so, that is just a myth and not really true. We recommend that you run your pump for an actual purpose and not a myth. Chemicals (CYA and FC) keep your pool clear and sanitized, not the number of times water passes through your filter. The filter is just there to capture all the junk that falls into your pool and floats. By the time your filter captures any algae, you have already lost the algae war.

The two main reasons to run your pump is to generate the chlorine your pool needs, if you have a chlorine tablet feeder, or have a saltwater system. The other reason is to skim the debris off the surface of your pool.

Once you accomplish these goals, you no longer need to run the pump.

Thanks,

Jim R.

 

[Daders]

Matt,

Just so that we are all on the same page... I suspect that the "changeover" you are talking about is the idea that you have to "turnover" x amount of water per day to prevent the pool from getting algae. If so, that is just a myth and not really true. We recommend that you run your pump for an actual purpose and not a myth. Chemicals (CYA and FC) keep your pool clear and sanitized, not the number of times water passes through your filter. The filter is just there to capture all the junk that falls into your pool and floats. By the time your filter captures any algae, you have already lost the algae war.

The two main reasons to run your pump is to generate the chlorine your pool needs, if you have a chlorine tablet feeder, or have a saltwater system. The other reason is to skim the debris off the surface of your pool.

Once you accomplish these goals, you no longer need to run the pump.

Thanks,

Jim R.

Great information, I was wondering about this as I asked our PB if I could just run the pump at night since we have free energy 8pm-5am. He said it is not recommended because of the sun's UV destroying the balance. Therefore I've been trying to figure out how to set up my filter pump for slow speed (1000rpm) during the daytime and full speed (3400rpm) at night to balance our FC to CYA. Only reason why I do like having the system running during the day is I am more likely to discover a pump or other problem more quickly.

 

[MattMoore]

To do what your saking @Daders is easily programmable with the VS pump integrated control with the timer function.

I want to be able to set up timers and have the heater increase speed of the pump.


I have the VS pump in now, but with the 260k btu gas heater I have to run at 2300rpm to get the flow through the heater. any slower and it heats the water too much that there is some boiling in the heater (light banging) and the heater shuts off.