Air conditioners are assumed to run for 8 hours per day? With 100% duty cycle? They shouldn't have published without the data. But the concept is good! I do wa

Air conditioners are assumed to run for 8 hours per day? With 100% duty cycle? They shouldn't have published without the data. But the concept is good! I do want to know which appliances make the most sense to update for energy conservation: I only run my microwave for 60 seconds a day and the energy it uses goes into heating food, kinda pointless to update that. But if I had $1000 to update my fridge or my water heater or my dryer, which gives the most bang for the buck? Is there an order of importance that makes sense for most houses? Personally, I'd get out my old Kill-A-Watt and run a study, but I expect someone's already done that. This just isn't it.