# Home energy monitoring in split floor with one compressor

I have an odd situation where I live on a floor split in two and I want to split the electricity bill fairly with my floormate. I am looking at the home energy monitoring systems that have all the little ampmeters that go around the hot wires in the panel.

The problem is that we use split system A/C, there is only one A/C compressor for the floor and the power for the indoor units comes back from the compressor.

I'm thinking I can use the hot wires coming from the compressor instead of the circuit going from the panel to the compressor to figure out relative usage. (Won't measure the amperage used by the compressor, but will know relative amperages of the individual indoor units.)

Am I on the right track? Will I have to run the return power wires adjacent to the panel for proximity purposes? Are there systems with wireless meters? This Emporia system on Amazon looks like it has two large ampmeters around the main wires and then smaller ampmeters for each circuit - does this system require the sum of the smaller ampmeters to equal the current of the large ampmeters? Because if I set it up like above, I won't put an ampmeter on the one circuit that goes to the compressor, and then the sum of the little ampmeters won't be the same as the total amps.

Kinda lost here, would love to figure out a good hack.

Thanks!

• Take the monthly bill, divide in half. Talk to the landlord about splitting the panel & metering so each flat/apartment gets its own bill. Since this is a rental, adding things to the panel may not be legal anyway. Apr 4, 2022 at 14:38
• Unless there is a large difference of power usage between the two of you, the difference in bills might not pay for monitors. Apr 4, 2022 at 15:11
• @FreeMan or if there's a significant difference in square footage, divide proportionally. Apr 4, 2022 at 15:37