We came home from vacation Sunday afternoon to a 100-degree heat wave. Although the air-conditioner was working well when we returned home, the house was hot Monday morning. Sense showed “other” rather than the Air conditioner running, and the condensate pump was not running. The fan in the compressor unit was running, the compressor unit was making noise, but it seems the compressor itself was not running. The vapor line of the compressor unit was not cold. I called for service, the technician arrived Tuesday night and I watched as he diagnosed the problem. Noticing how he used temperature and pressure readings to diagnose the unit gave me an idea. What if these key operating parameters could be monitored continuously?
A brief Internet search identified Alert Labs as active in this area. They offer an air-conditioning monitoring product and service called Sentree. See: https://alertlabs.com/pages/sentree I sent them an email asking if they have something more tailored to homeowners and integrated with Sense. They have not yet answered my query.
A simple system would monitor the temperature of the vapor and liquid connections at the compressor unit or the evaporator unit. A more complete system would also monitor pressure at those points and monitor ambient temperature, room temperature, and perhaps plenum temperatures. This could be integrated with sense monitoring to report electric usage per degree day, or per BTU of cooling. Such monitoring could also report changes that indicate early warning of refrigerant loss, or system efficiency reductions.
If anyone knows of such a system, or is developing such a system, please let us know.