just thinking

bought a window a/c for the shop. had a yellow tag that claim it would use $35 worth of power a year.


How is this measured, do they make some type of watts meter like the power company meter. Can one buy one of these items? I was just thinking about measuring my water heater, a/c etc.

But mostly I,m just thinking.......... its raining outside.

 

The fine print on that sticker explains what the number means. It is similar to when the car manufacturer says you'll get 29 miles per gallon. You need to apply a "your mileage may vary".

The $35 figure is for comparison to other air conditioners only. If is for a typical house in a typical climate with typical residents, using the national average electrical rate. They assume some sort of average number of hours per day and days per year of operation.

 

For fun (if you find it fun), you can purchase a watt-hour meter and connect it to the air conditioning circuit. Then using the rate table on you bill, do the math.

John stated it right on the money, typical climate typical cost per watt-hour, typical.......

If you want to get an idea of what it really costs without buying a watt-hour meter, you can measure the current it draws, multiply that instantaneous number by the voltage, then multiply that number times the number of hours you think it runs in a year. It doesn't include information about power factor, but it will give you an idea.

 

As for the question about the watt-hour meter, Yes, you can purchase one. There is one on the market that goes by the name of EMON-DEMON. They are very simple to install and work very well.

 

you should stop thinking.