“Be kind, for everyone you meet is fighting a hard battle” - Often attributed to Plato but likely from Ian McLaren (pseudonym of Reverend John Watson)

## Tuesday, June 14, 2011

### Central Air for sale - cheap!

I'm attending the Clean Technology Conference and Expo 2011 in Boston, MA. One of the featured programs is the CTSI Utility Challenge, where early stage firms in the Clean Tech "space" vie for recognition of their technology by a panel of judges from the Utility and Municipal sectors.

One of the 15 finalists was 7AC Technologies, a firm whose technology uses a "Liquid Desiccant Chiller" for cooling buildings. The Company's representative caught my attention when he stated that "a typical residential central air conditioning unit costs as much annually to operate as its initial purchase price." Really?

I looked into the A/C unit at our house in Anaheim Hills (not known for a Mediterranean climate, and I like it very cool) in a post in 2009. I determined at that time that the 1995 Goodman Manufacturing unit draws about 5,890 watts when cooling. I'd measured it at about 5,000 watts but I'll go with the higher number to make my point.

I will estimate on the high side that the A/C unit is on about 12 hours per day for 150 days per year. This certainly does not underestimate its usage. Thus, I'd use 12*150*5.89, or 10,600 kilowatt hours. I'm paying $0.14/kilowatt hour so this usage will cost me slightly under$1,500. And I'm in a hot area, with an old and inefficient A/C unit with our thermostat set at around 70 degrees Fahrenheit.

I want my new central A/C unit for \$1,500! I wonder why the speaker felt it necessary to MSU (make s _ _ t up)?