someone asked about large scale heat pipe applications? how about a heated driveway that is powered by the earth?
https://pangea.stanford.edu/ERE/db/W...2015/29041.pdf
By the way I love this thread. What's the lowest Hz you've run the compressor at? from what I've read on split systems (mini or full size inverter systems) there's a minimum speed, and separately a minimum speed that must be run occasionally to achieve good oil return. is this just not an issue on a system so small (pipe-wise, not capacity)?
I'm also wondering if you've considered the need for a receiver. is this unnecessary again? or perhaps effectively included in the volume of your bphx/dryer? some of the refrigeration machines I've seen have receivers nearly equal in volume to the compressor housing itself.
If there's any more details you'd like to share on the operation of the VFD than what you've posted so far, I'm very curious to hear it.