2 speed vs. variable speed pump

[Arobeth]

Hi,

I am looking to replace my single speed pump with either a 2 speed pump or a variable speed pump to reduce energy costs. Is the extra cost of the variable speed worth it?

How much will I save with either of these options vs my current pump?

Currently I run my 1 hp single speed hayward max flo for 8 hours a day.

Thanks,

 

[jblizzle]

What is the cost of your power per kW? A 2-speed will get you most of the savings, but if you power is very expensive, then a VS pump could save enough more on power to offset the added cost. It does not look like you have a need for a bunch of speeds and would be using the low speed almost all the time.

Another thing to note is that the electronics in VS pump are more susceptible to damage from nearby lightning strikes.

 

[Arobeth]

My cost per KW is 11 cents. How can I calculate how much I am spending per day today and estimate how much will I spend with the 2 speed pump? I just want to understand the monthly savings so I can calculate the payback period.

Thanks

 

[Griswald]

A 1 HP motor requires 746 watts to run, but that assumes 100% efficiency, a 1.5 factor gets you just over 1100 watts.

 

[jblizzle]

Your power cost is too low for a VS to make financial sense; go with a 2 speed.

Mas985 has spreadsheets in his signature to estimate costs. Basically, running on low speed will move 1/2 the water using 1/4 the power. So even if you double the run time on low, not usually required, you would save 50% the running cost.