variable speed pump

[bradc344]

1. Looking to save some money on my electric bill
2.yes they offer a $200.00 rebate plus I can sell my old one for a few hundred dollars
3.not sur on electric rate I'm in phoenix with APS will look it up
4.yes my controller is compatible plus the pump I'm looking at has a timer build in
5.Small water shear that we dont us that often
6.the plumbing is 2 inch
Thanks for the reply

[mas985]

I think the highest tier in your area is $0.11/kwh. So assuming typical 2" plumbing, here is the running cost for a single turnover.

Typical 1.5 HP Pump: $17.43/month

Intelliflo running at 3144 RPM to match flow rate of 1.5 HP pump for the in-floor system full time: $15.62/month

Intelliflo at 1000 RPM when not running the in-floor system at all: $3.14/month

So worst case, your savings will be about $2/month which would take a long time to pay off the VS. At a cost of $900 for the pump, break even would be 450 months or over 37 years.

However, if you are able to split the run time with the in floor system and run 50% at 1000 RPM, your savings could be up to $8/month. With the same pump cost of around $900, break even would be around 112 months or a little over 9 years. Not great but maybe worth it.

Another option would be to replace your current motor with a two speed motor. At a cost of around $300, you would save about $5/month with running 50% at low speed but break even would be around 60 months or 5 years.

Note too that it would take over 16 years before the VS would become more cost effective than a two speed motor swap.

It really comes down to how much you will be running the in-floor system. They tend to be power hogs.

BTW, I forgot to ask how long you run your current pump?

[bradc344]

I heat my pool with a heat pump and right now the system is on about 12 hours a day in about about a month I will be able to cut back to about 8 hours a day which is were I run it the rest of the year thanks for the reply very informative you probably just saved me some money my current system is only three years old so I will just leave it alone thanks again......

[mas985]

The heat pump requirement changes the economics by quite a bit because you are forced to run the pump longer than what you actually need for just circulation. I did my analysis based upon a single turnover but at 12 hours you are over 5 turnovers.

Even 8 hours per day is way more than what you need since it is over 3 turnovers. With 2" plumbing you are probably getting close to 90 GPM which would be about a 2.25 hour turnover. So you could save a lot of money just by reducing your run time by a lot and still have a clean pool. Also, the heat pump should be able to work on low speed of a two speed pump so you can save even more by changing out the motor. If you have to run 12 hours a day for the heat pump, that would shorten your break even by at least half.

[bradc344]

The twelve hour run time is only dec, jan even then till mid spring and early fall it runs at least 4to 6 hour a day go to know about the turn over because I can really reduce my run time in the summer months when we are gone ,thanks again for the help ......

[CarlD]

If your controller can also control a 2spd pump, then you'd ONLY run on high for pool cleaning, and run on low the rest of the time. I don't know if low speed is cheaper than VS, but the rebate and the difference in pump cost may make it a wash...and 2spds are probably simpler to maintain and fix.