INDEX to the series
Last August, I was thinking about how my winter heating needs related to my electrical energy use. Whatever the source, requiring less heating requires less electricity in most cases (unless your primary heat comes from a wood stove perhaps?).
To require less heat, I blocked off the sun porch with a heavy curtain and closed the heating vents to isolate the that room from the rest of the house. Why heat a leaky room? The house has started forming icicles. I have some of the finest icicles in Lion's Head. But the icicles are not forming on the sun porch eaves! As you can see in this pic from a couple years ago, they hadn't formed by mid Jan 2015 either so we will have to see if I have reduced my heating requirement.
As I will show below, the oil furnace burns heating oil but it uses a fair bit of electricity, about 620 watts while it is running. About half of that electricity is doing useful work contributing to combustion, about 1/2 of the electricity is turned into heat through inefficiency and is "wasted". I remind myself that this waste heat helps to heat the house, so about 310 watts of the electricity is heat input which I need, the rest runs the two motors and the spark coil in the furnace which is also good.
Steve Lavimoniere, one of my favorite burner techs on Youtube.
I am not recommending you work on your own furnace, not at all! But the more you know about your machines, the better decisions you'll make.
I first looked at my furnace on the smart meter back in November. Now it is coming on regularly, about every 1/2 hour for about 20 minutes when the outside temperature is about -10C. It runs 24/7 at this temperature although the spacing between cycles and the run time will vary with the outside and what I tell it I want for the inside temperature (the setpoint).
During this test, the house base load is steady at about 80 watts. The furnace starts at 8:50 which both the burner compressor/fan and ignitor coming on. The house usage jumps to about 375 watts. Subttracting the base load gives a furnace draw of (375-80=) 305 watts. The furnace runs for about two minutes until the main furnace air mover fan comes on and the total load becomes about 700 watts. Again, subtracting the base load gives a peak draw for the furnace of (700-80=) 620 watts. Combustion stops when the thermostat reachs set point and the compressor and the spark stop operating. The total usage falls at about 8:58 to 500 watts or (500-80=) 420 watts. The furnace stops at 9:03.
I would like to be able to build a chart of furnace cycle time versus temperature as I have done for the other major appliances (fridge, freezer and water heater).
I haven't shown you those yet - coming up.
Mooney Wall. The idea is to reduce the thermal bridges in the wood by crossing the strapping at right angles to the rafters and studs. This pic shows my progress.
I was a bit concerned about double vapour barrier effects but I found some interesting reading about that here. I believe that since I am going to cover the wall with air and water vapor permeable tongue and groove wood strips there will be lots of gaps in the covering. If there is any condensation on the inside of the poly, it should be able to escape back into the room? I am doing the smaller of the two rooms upstairs as an experiment.
Thank you for your interest,
Lion's Head, Ontario, Canada
INDEX to the series