Using VFDs at Home

Until:

• Nagging to unplug
• Thermostats
• Time-switches
• Draught exclusion
• Loft insulation
• Substitute high efficiency lighting
• Multiple glazing
• Supplier switching

have taken place, forget it.

Anyway, most homes are single phase.

What on earth is sufficiently large at home that needs a 3-phase motor to turn it (rhetorical question - NNTR)?

here is a device that would benefit from a 3 phase motor

https://www.youtube.com/watch?v=qMsObwqD788

I would try another approach, maybe a water tower...

This is certainly possible. It will be far from practical and efficiency improvements will be dubious, at best. To say for certain will require knowing a lot more about your system.

Now if the old motor fails and needs something to replace it then I might consider switching to a three-phase motor and driver system. Most of the efficiency improvements will be due to improvements in the magnetic properties of the newer motor but don't expect significant improvements.

​_https://www.ato.com/single-phase-vfd

There are inexpensive VFDs for typical single phase motors, mostly split capacitor types, running plus starting winding energized at all times. HVAC people use them on blowers for some designs to get your 16 SEER. For pumps and fans you will save some electric cost if the impeller is not matched to the service, I.e. if your pump pressure only needs to be 40 psi and your pump produces 60 psi at normal run. Or your fan is blowing hard against partially closed dampers.

most of your kw go to flow, either CFM or GPM, so if you can reduce those, then you might have some savings worth investigating a new add-on VFDS. To convert to 3 phase motors is unlikely to be achievable, let alone economical.

try this

https://www.youtube.com/watch?v=ZqnfLHhuuUQ

I think almost any washing machine one buys today (for normal home use) has a three phase motor supplied by a VFD and operated from single phase. No gearing or crank for agitator. Just reverse motor to agitate and increase frequency to spin.