How do I calculate the energy usage of radiant heating?
October 23, 2012 8:43 AM Subscribe
How do I work out the energy usage of built in radiant heating?
posted by madajb to home & garden (11 answers total) 1 user marked this as a favorite
My circa 1967 house has built in electric resistance ceiling heat.
It is quiet, effective and generally great. Except when the bill comes.
Since it is zone-based, I've been toying with the idea of just putting a couple of oil-filled space heaters in the rooms that get used.
Thing is, I'd like to calculate before hand whether this is likely to save me any money.
The space heater is easy, just plug 1500 watts into the cost calculator and we're done.
But how can I work out the wattage of the built in heating?
As I said, it's set up in a zone system, with 1 wall-mounted thermostat per area, with (I think) 4 breakers in the panel.
There are no detachable plugs in the system, so no place to plug in a kill-a-watt.
The three ideas I've come up with are:
A) removing the thermostat on the wall and putting a voltmeter inline. I don't think it's a low-voltage thermostat, but I don't know for sure.
B) Figuring out some way to measure at the circuit breaker and just turning on the area I am concerned about.
C) Throwing all the circuit breakers in the house so there is no load, and then just turning on the heat circuit and observing the outside meter spin.
Any of these sound plausible or practical?
Any better suggestions?