I once created a telemetry/alarm combo for supermarket freezers and = residential HVAC. It had two sensors. I think they want across the = evaporator. I do know that measuring superheat was the key. I never = really understood what that meant but it was a key factor in determining = the health of the system. It was for an insurance company. Hartford = Steam Boiler Company. Enron bought them and I never got another order. =
-----Original Message----- From: AF [mailto:[email protected]] On Behalf Of Seth Mattinen via = AF Sent: Thursday, June 12, 2025 11:44 AM To: [email protected] Cc: Seth Mattinen <[email protected]> Subject: Re: [AFMUG] Air Conditioner Monitoring On 5/27/25 12:34, Adam Moffett wrote: > Does anyone here monitor air conditioners? If so, how do you do it? >=20 > Up until now, I would find out about an A/C failure by getting=20 > temperature alarms from equipment. When I look at the chart of=20 > temperature over time it usually looks the A/C fail happened hours=20 > (sometimes many hours) before the temperature got critical. It'd be=20 > nice to respond sooner. One simple thing to start with is take two temperature sensors and place = one in the air stream before the coil and one after the coil. If the air = temperature drop is less than 20 degrees F while it's running in cooling = mode, you are going to have a problem soon. Getting a little fancier: tap all of the thermostat wires and contactors = so you can read all of the control wiring states. i.e. if the tstat is = calling for cooling but the compressor contactor is still de-energezed, = you have a problem. Adding a differential pressure switch across the blower can detect = blower motor failures and/or weak airflow depending how sensitive it is. ~Seth -- AF mailing list [email protected] http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list [email protected] http://af.afmug.com/mailman/listinfo/af_af.afmug.com
