saving money on heating with some algebra

Time for some math..

Let’s make some VERY rough estimates:

1. heat is on from 8am to 12pm normally (16 hours a day) and off completely at night.
2. using a unique under-desk heater pane (link below) while I work in the evenings would reduce whole house heat needs by 2 hours.
3. but the panel costs $66 and uses 150 watts
4. avg heat bill per month is $300 (I have no idea… just a guess)

So that means…

$300 * 2/16 = $37.50 saved per month by turning off the heat for 2 hours of 16 per day

150 watts * (1KW /  1000 watts) * ($0.20/ KWh) * 2 hrs * 31 days = $1.86 per month spent on electric heat

So ~$36 saved per month

So the break-even point (on cost) is N months

$66 = $36 * N
N = 1.83 months

You could also do the break-even analysis using “primary energy” used to account for the difference between
electricity used vs heating oil, but I am happy enough with this.

BTW… the reality is that the overnight temps on cold nights drop dramatically and the furnace turns on a bit to keep
the house at 58F which I think is about the limit for comfortable bundled up sleeping.  So that’s factored into the 16 hours.

THE HEATER:  Idus-Tool Cozy Legs Flat Panel Radiant Heater

I’ll report back on how it goes.


1. This is why zoned heating is useful

2. Gary at does something similar with an electric mattress for sleeping, but I would personally be worried about EMF with it right next to one’s body…  LINK  ($’s saved/year $186)


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