220 vs. 110v SWG

[Poconos]

Don is right. Heat is wasted electricity. As for efficiency it all depends on the I**R (current squared X Resistance) = Watts or heat. You can play games by cutting the wire size for 240 vs 120 wire runs and this can negate any I**R savings but the one-time cost of the wire run will be less. However using a lower resistance run for a 240 application will reduce the recurring cost of wasted heat. Another reason for using 240 on residential high current devices is to balance the load on the legs from the pole transformer.
Al

[mas985]

I also agree that a pump operating at 240v has better efficiency than one running at 120v but I don't think it is that significant. The losses in the wires feeding the pump are not that significant either.

Let's assume that the wiring is 12 awg and that the run from the electrical box to the pump is 25 feet. 12 AWG wire has about 1.6 ohms/1000 feet of run. So for 25 feet, that is about .04 ohms.

Say you had a pump that could be run at 120v @ 16 amps or 240v @ 8 amps. The loss in the feed wire would be 10 watts @ 120v or 2.5 watts @ 240v. But if you compare it to what the pump is drawing at 1.92 kw, that is only 1/2% @ 120v or 1/8% @ 240v. Not a lot different compared to the pump itself. Even the pump generally will run less than a few percent more efficient @ 240v. You could probably make up the difference by running your pump a few minutes less each day.

A SWG would probably have the same % power loss but they run less than 200 watts so the absolute loss would be much less.

The difference between the two is fairly minor but having said that I would still always go with 240v if the cost of equipment is not that much different and easily available.