Sunday, April 30, 2017

heating degree days 2

INDEX to the series

(click graph to enlarge)

This graph shows my progress at using less electricity for heat.

The blue line is the 2016-2017 heating season. The blue line is lower than the others and slopes less. The graph tells me that I used less electricity per heating degree day last year than the previous three years.

Although I heat with an oil burning furnace, a fair amount of electricity gets used to power the two motors in the furnace, about 600 watts while it runs. If it runs less often, it uses less kWh.

The graph was simple to make and only requires two numbers for each month. One number, the total kWh used, is from my electricity bill. The second number is the heating degree days for that same month that the electricity was used from a government site like the one I showed in the previous article. A copy of my spreadsheet (.xls) is here.

I made a number of improvements in the house to reduce heat loss but particularly last summer (new insulation, leaks plugged, air circulation cut from the sun room and a new door) so it is good to be able to show the improvement in spite of changing weather.

I am ignoring price here and focusing only on the kWh used and the outside temperature as expressed in the heating degree days for my location.

Last winter was not as cold as the previous three but that does not matter when the data is compared as kWh per heating degree day.

Thanks for your interest.

George Plhak
Lion's Head, Ontario, Canada

INDEX to the series

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