The following stumper is presented in BPI's August Performance Matters e-Newsletter.
For this month's stumper, Ham Niles of Evergreen Home Performance provided this story about the home of a retired anesthesiologist and his wife in Maine.
"The couple lived in a home less than 20 years old. They had a tight house, solar hot water, under-floor heat, efficient windows, modern electric appliances for laundry, dishes and cooking, and a backup generator with a block heater and battery charger for when the power goes out, which it does frequently in this town on the coast of Maine.
The homeowners complained that there was high electrical usage that seemed out of proportion with their habits - as though they had a hot tub or AC running all the time.
We evaluated the house top-to-bottom, and found plenty of load - thirteen 90 watt can lights; several pumps for the under-floor heat; various phantom loads associated with printers, Tivos and a security system; but nothing that added up to the 12000 kWh the client was annually seeing. I recalled a story my boss told me about how to use the IR camera – and that led to directly solving the problem. What was it?"
Hint: Infrared of back-up generator (top left) and infrared of circuit breaker (top right).
Its the block heater.
I agree with Lain. The block heater is on continuously keeping the block at a nice 121 degrees. The circuit breaker assumably shows the active circuit to the block heater when the generator is on stand by.