Multiple AC Units


I’m in the same boat with loads that I am VERY sure of what they are, and are yet “unknown” (AC compressors, UPSs, etc.). I would love to know the power my various computers are using, but can’t since they all show up in a bucket of high frequency power supplies that are "always on.

"I’m starting to think I’d be much better served with one of these:

No offense to Sense. It does amazing things with sampling rates and machine learning, but there are some things that are just beyond the reach of a single pair of induction clamps.


My American Standard A/C system seems to be reporting accurately and it has the compressor and blower consumption combined.

It is a single compressor and the blower is an ECM variable speed. It has the Comfort R fan profile setup(also used by Trane) so the blower ramps up to 50% at start up, then 80% after a minute, then 100% after 7 minutes. Sense is able to pickup the power increase from the blower ramping up speed.

I’m ok with the combined reporting because the furnace using a different fan speed from cooling when in stage 1 or stage 2 heat. Heat also does not used comfort r profile so the wattage will be different


My Sense has been able to detect and unravel the differences between my two Bryant single stage ACs. One is 33k BTUh unit and the other is 48k BTUh unit so there are differences in the power profile. The 33k unit is a merged composite of two different auto identified components, whereas the 48k unit was found as a single device. I’m not sure if it helped, but I do run my upstairs and downstairs furnace/AC blowers every hour, for 5 min, which seems to have helped with identifying standalone blower operation.


@ dgeist thanks for the link to the greeneye. After doing a lot of reading on their site and forum and getting feedback, I have requested a quote for a system that will be able to monitor 78 circuits. 2x 32 channel GEMs and 2x ECM-1240s. There is no “learning” involved and everything will be picked up instantly as soon as the system has been installed.

It is a lot more work and a lot more expensive, but it just works. It of course won’t be able to tell my toaster oven from my microwave since they share the same circuit, but all the things I really care about (3 HVAC systems, always on UPS’s with loads on them, pool pump, well pump, dryer, fridge, etc) are all on separate circuits, so I’ll be able to track all of that from day one.

I can monitor the data from my computer instead of being forced to use the little screen on my phone. And I will be able to combine readings from a sub-panel 200 feet away in a separate building and no longer will the loads in that building count against my solar production.

I have enjoyed Sense and will continue to keep it in the system as I do like the GUI, as small as it is in a phone, and I really like how it overlay’s production and usage on the power graph, but not being able to detect any of my large loads in a consistent matter, means I have to go elsewhere for that data. After 9 month of use, my Always On represents 60.9% of my overall usage, and Unknown another 29.3%. So only 9.8% of my usage is actually allocated to a specific device.