I would find compressor manufacturer's data and extract the information from that. Or get a parts house book and see if it provides capacitor info with the model of compressor you're working with. Johnstone's catalog is good about listing start and run caps with the single phase comps, plus which start relay to use.
Building Physics Rule #1: Hot flows to cold.
Building Physics Rule #2: Higher air pressure moves toward lower air pressure
Building Physics Rule #3: Higher moisture concentration moves toward lower moisture concentration.