Great idea. I'm sure we'll have plenty of discussions about all the different types of refrigeration, equipment, and heating methods related to heat pumps and air conditioners, although it seems this thread is open to anything.
Since this is one of the first posts, I'll post some of the most helpful resources for commercially built equipment, stuff things people can buy.
One of my favorite resources for mini-split heat pumps. This provides information for heat pump performance data at 5 degrees F, which to me, is far more useful information where I live than 17. The unfortunate part is this isn't necessarily derived from third party testing like AHRI data is but I think it fills in the gaps reasonably and also gives some data on pan heater operation. This data is information provided by the manufacturers so there is a chance that it isn't consistent and even a possibility that results could be inflated or changed. Particular pieces of note for me are the maximum capacity at 5 degrees and the input power and COP at that capacity. It's interesting to see some of these units pushing out reasonable amounts of heat with COPs above 2. That's something I didn't expect.
http://www.neep.org/initiatives/high...urce-heat-pump
For furnaces, air conditioners, heat pumps, boilers, etc. The AHRI ratings ARE third party tests performed in a consistent lab. The site allows you enter criteria, get results, and sort by column for the information that's important to the person searching.
https://www.ahridirectory.org
I've spent a bunch of time playing around in the AHRI directory site and have contemplated which systems I would buy for different scenarios(higher loads vs lower building loads, looking at what furnaces use the least electricity, looking for the best cooling EER in a system, that sort of thing.
Hopefully others find these resources helpful.