Pounds of Coal Used Per "Heating Degree Day"

Short Bus wrote:Isayre,
These were my thoughts on the Heating Degree Day and coal usage discusion.
So You Want to Compare Coal Usage.
I thought it was neat, but to each his own.

Short Bus: I have added my guesstimated figure to your thread. Glad to see that others have been toying with "degree days".

Amazingly it seems to be more linear then I would have thought.

The data analysis and resultant graph were done mostly for the purpose of finding the the pounds per hour needed to keep the fire going when no heating is required. I agree with your initial thought that the relationship is non-linear. What makes the left side (higher HDD) of the graph look linear is from from a couple of things:
1 – The stove is located in the center of the house and during mid-cold weather the extreme ends of the house are colder than the center. If this was a coal furnace then I am sure the usage would go non-linear in order to maintain uniform heat in the house.
2 – A factor that I call the “WAT” (see below). When the WAT alarm goes off and it appears that we are in a deep cold spell, I start up a wood stove located in the basement. This takes the load off the coal stove and silences the WAT alarm.

WAT - short for “Wife Acceptance Temperature”.
When a couple first gets married the WAF communication is usually a nice sentence like “Please turn up the heat”. After 40 years of marriage it reverts to a rather primitive form of communication, in this case its a series of short and heavy steps to position the body of the alarm in front of the coal stove, followed by a few loud outbursts of “brrrrrrrrrrrrrrrrrrrrrrrr”.

We're the exact opposite here. My wife likes the house to be about 5 degrees colder than I like it set at. Obviously the WAT factor is non-linear also.