Heating your home is a major expense during the winter months, and it's important to choose the most cost-effective and efficient method for your needs. Two popular options are an oil furnace and an air source heat pump. In this article, we will compare the efficiency and cost per million BTUs of these two heating systems.

Efficiency Comparison

The efficiency of a heating system is measured by its Coefficient of Performance (COP), which represents the ratio of heat output to energy input. A higher COP means greater efficiency, as more heat is produced per unit of energy consumed. An oil furnace typically has a COP of 0.84, meaning that it produces 0.84 units of heat for every unit of energy it consumes. In contrast, an air source heat pump has a COP of 3.0, which means it produces 3 units of heat for every unit of energy it consumes. This makes the air source heat pump much more efficient than the oil furnace.

Cost Comparison

The cost of heating your home is determined by both the efficiency of your heating system and the cost of the fuel or electricity that powers it. Let's compare the cost per million BTUs of an oil furnace and an air source heat pump. To calculate the cost per million BTUs, we need to consider the cost of the fuel or electricity, as well as the COP of each heating system. For the oil furnace, we'll assume a fuel cost of $4.30 per gallon which is the New Hampshire average, and for the air source heat pump, we'll assume an electricity cost of $0.30 per kWh which is the current Eversource rate in NH.

Oil Furnace Cost per Million BTUs

The heat output of a gallon of oil is approximately 139,000 BTUs. To produce 1 million BTUs of heat, an oil furnace would consume:

1,000,000 / 138,500 = 7.22 gallons of oil

At $4.30 per gallon, the cost of 7.22 gallons of oil is:

7.22 x $4.30 = $31.05

However, the oil furnace has a COP of 0.84, which means it only produces 0.84 units of heat for every unit of energy it consumes. To calculate the actual cost per million BTUs, we need to adjust for this:

$31.05 / 0.84 = $36.96

Therefore, the cost per million BTUs for an oil furnace is approximately $36.96.

Air Source Heat Pump Cost per Million BTUs

The heat output of 1 kWh of electricity is approximately 3,412 BTUs. To produce 1 million BTUs of heat, an air source heat pump would consume:

1,000,000 / 3,412 = 293.1 kWh

At $0.30 per kWh, the cost of 293.1 kWh of electricity is:

293.1 x $0.30 = $87.93

However, the air source heat pump has a COP of 3.0, which means it produces 3 units of heat for every unit of energy it consumes. To calculate the actual cost per million BTUs, we need to adjust for this:

$87.93 / 3.0 = $29.31

Therefore, the cost per million BTUs for an air source heat pump is approximately $29.31.

Conclusion

An air source heat pump is much more efficient than an oil furnace, with a COP of 3.0 compared to 0.84. When factoring in the cost of fuel or electricity, an air source heat pump also has a lower cost per million BTUs, at approximately $29.31 compared to $36.96 for an oil furnace.