- A typical central air conditioner uses at least 2000 watts per hour, or 2kWh, and this may be on the smallish side.
- A newer, quiet and efficient whole house fan that moves air at the rate of 1530 cubic feet per minute uses 44 watts per hour, or 0.044kWh.
- 2000kWh/44kWh=45.45, so a whole house fan uses 45 times less energy than a central air conditioner using the above numbers.
- Therefore, the energy circle associated with the central air conditioning grows at a rate 45 times the amount of the energy circle associated with the whole house fan. The circles grow at the same rate when both houses are using air conditioning.
- Given electricity rates reported by the Department of Energy of ~11 cents/kWh, the above example would cost $4.40 per day if using only central air conditioning. When using a whole house fan, this is reduced to $0.45 per day. If this occurs 60 times during the summer, you’ve saved over $235.00 in one summer.
- Electricity rates are increasing according to these official Department of Energy statistics, more than doubling over the past 20 years. If we extrapolate these rate increases, then the savings 10 years from now would accumulate to over 3000 dollars, paying for the whole house fan and then some.
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you did a super job on this blog!!! Thanks for all the work you put into this. My son and his wife are buting an all-electric house in Colorado and need to cool the upstairs especially. Your site is excellent!