We have a very old (20-25 years old) window ac unit in the living room and I'm trying to figure out how efficient it is. I can't find out the model number or any statistics about it. The manufacturer website doesn't have any info about old models either.
I can measure the KWh consumption, but that won't be of any use without a way to figure out its BTU. Any creative suggestions on how I can measure that?
Alternatively, just some historical data on window ac's from that time period, like their average COP, would be really helpful.