ON THE ROAD TO ENERGY SAVINGS....

One of the things we want to achieve with the old house we live in is to reduce our carbon footprint and reduce fuel costs. Our initial step was to figure out how much energy our 1516 sq. ft. old house has historically used to provide heat and hot water. As you can see from the image below, most of our basement is stone and dirt. Luckily my organized wife had kept all our furnace oil bills since we owned our house. Our average liters of furnace oil consumed per year from 2013 to 2022 was 2,746 L. Using data provided by the Efficiency Nova Scotia website, we know furnace oil generates 36,500 BTU/L. Therefore, on average our old house has used 100,229,000 BTU or 100 MBTU per year to heat our home and provide hot water.

Efficiency Nova Scotia’s (ENS) website gives some great data and examples for home energy usage for a variety of heating methods. For a 1700 sq. ft. home they calculate the average energy consumed to heat the home with furnace oil is 65 MBTU. They do a separate calculation for hot water, which gives an additional energy of 32.5 MBTU for a tankless coil oil furnace which is the kind we have in our house. Combining the two, ENS's prediction of average energy use for heat and hot water would be 97.5 MBTU. Based on this, our old house compares reasonably well to the ENS calculations. Interestingly, ENS does a similar calculation for what they call an “old house” where the energy to heat the home is 80 MBTU, for a total of 112.5 MBTU for heat and hot water. Again, our old house is comparing reasonably well.

This comparison is a bit of a surprise. Our oil furnace is 27 years old and internet sources suggest that an oil furnace this old would have an efficiency in the range of 60 to 75%. A value ENS uses for an old oil furnace that gave the 80 MBTU energy consumption calculated above is 70% efficiency. So is our furnace more efficient than I thought? Not likely. The fact that we keep our thermostat set at 64 °F during the day and 58 °F at night during the cold weather may account for a lower energy usage than the ENS calculations. Our house is also a little smaller (1516 sq. ft.) than the 1700 sq. ft. ENS example which may also factor into the favourable comparison.

I don’t think our house is very well insulated. The basement and crawlspace have no insulation on the walls or ceilings. We think the outside walls of the 1^st and 2^nd floor have some blown-in insulation but it has settled in the wall cavities. Our attic does have some insulation, so it appears there is lots of room for improvement.

Even though our old house seems to compare well with what might be expected, we want to see what we can do to reduce the energy consumption of our old house. Hopefully, this would allow us to reduce the cost of heating and reduce our contribution to greenhouse gases to help mitigate, in our small way, the impact of the climate crisis. Our next steps will be to get an energy audit and have our house assessed by professionals for insulation improvements. Stay tuned for the results of these tests!