Hope I'm not opening a can of worms here.
I've been away from this market for several years. I always thought/wanted something that would link multiple A/C units and control the timing of their compressors turning on,
You know, to make sure they stagger and don't hit your demand all at once.
So... has anything like this been developed? Something commercial.
Hey,
It depends on what exactly you want to do I guess. Is this for a house unit, mini-split in an RV, roof-top RV unit, or something else entirely?
Most of the house digital "smart" thermostats (NEST, Honeywell, etc.) will work together in a multi system situation. That is to say, you can program them with a certain amount cooperation. They are, IMO, vastly overpriced, but people do seem to like them. I also don't trust the software running on them. I'm not a fan of reporting back to anyone how and when I use the things in my house.
Most modern multi-zone mini-split systems already work in this manner because they share the same condensor/compressor and the compressor itself is variable speed DC.
All that being said, thermostats are really simple devices. They basically just tell the unit when to start the fan, to heat, to cool, etc. With a little bit of known how, you could certainly build your own "smart" thermostat from a Raspberry Pi, Arduino, or similar SBC.
I had one of those in my 1996 Fleetwood Discovery motorhomes and it worked great. Not sure how it worked, but it prevented both units from starting at the same time. Seems like a pretty simple circuit but if you can find out what they call them, you can probably order one on Amazon. Or find one in an RV junkyard if you have time.