Should you use a vf pump

[dalehileman]

Thanks once more geek. The 2-speed then is out since the entire purpose of switching to vf is diminution of our electric bill. Looks more and more, alas, as if I'm at the mercy of expensive complex subminiature weather-prone electronics

[mas985]

While the energy savings for an Intelliflo may be more than a two speed pump, a two speed pump can still save you quite a bit of money.

I went from a 1 HP single speed to a 1/2 HP two speed and was able to reduce the energy consumption by about 50%. Had I gone with an Intelliflo, it would of reduced the energy consumption by 65% so a bit more.

[ddalehileman]

Thank you again mas. From Internet reports I understand that savings even significantly higher than 65% are possible at even lower flow rates presumably without loss of other functions

[dalehileman]

....the question being whether pumps are made at these lower rates but without the electronics. So far it seems not though if someone in the know should provide a link to a pertinent catalog I'd be much indebted

[mas985]

Cost savings that you see published by variable speed vendors are usually unrealistic. They assume you are only running the pump at the absolute most efficient RPM possible. My numbers assume a more reaslistic scenario where I run the pump at least 2 hours a day at higher speed for solar and for my suction cleaner.

I have a pump cost comparison spreadsheet located here which is setup to help you determine the lifetime costs of various pumps. The scenarios are setup so that you can compare a single speed pump to both two speed pumps and variable speed pumps. The lifetime costs are determine with both the cost of the pump and the energy costs over the lifetime of the pump. Because the variables cost more, the lifetime costs are not that much better than a two speed pump but it does depend a lot on what you pay for electricity and how long you run the pumps.

[dalehileman]

Thanks once more mas, I had wondered whether those reports might not be exaggerated as I had questioned whether a vf pump run at low speed could efficiently clear flotsam, a very important consideration as I'm getting old and am horrified at the idea of performing this task manually every day. If I were to acquire a vf but find it necessary to run it at high speed for two hours a day I'd probably see almost no saving whatever since currently I run my 1 hp pump for only three hours with most satisfactory results. However I shall Fwd your post to an engineer friend who is much better than I at such judgments and who has most kindly offered his help

What I resent about the whole shebang is the almost universal assumption by the Establishment that the pool owner must not only be wealthy but must have an engineering degree with a minor in chemistry, but with many thanks for all your past and future participation