How do I figure out the cost differential between turning on an inefficient furnace and using oil-filled space heaters? Answered
the big deal is that this furnace also heats the upstairs unit of a
duplex, which i also own and rent out to my brother in law. the
deal is that he spends maybe 5 nights per week at his girlfriend's
house. so, if i turn on the furnace, all of the heat that goes
upstairs will be wasted.
i'm interested in learning how to measure energy usage and learning how to determine the usage difference between running the furnace, which is about 50 years old and runs at about 50% efficiency and three pretty standard 7-fin oil-filled space heaters. the flat in which i live is about 800 sq.ft. and the upstairs space is about 600 sq.ft. the windows are old, but are covered with plastic shrink film for better insulation.