How to Calculate Propane Versus Oil Heat: A Comprehensive Guide

When it comes to heating your home, the choice between propane and oil can have a significant impact on your energy costs and environmental footprint. To make an informed decision, it’s crucial to understand the factors that influence the cost of heating with these two fuels. In this comprehensive guide, we’ll dive deep into the details of how to calculate the cost of propane versus oil heat, covering everything from BTU values to system efficiency and maintenance costs.

Understanding BTU Values and Fuel Prices

The first step in calculating the cost of propane versus oil heat is to understand the BTU (British Thermal Unit) values of each fuel. BTUs are the standard unit of measurement for the amount of energy required to raise the temperature of one pound of water by one degree Fahrenheit.

According to industry data, the BTU values for common heating fuels are as follows:
– Heating oil: 138,690 BTUs per gallon
– Propane: 91,500 BTUs per gallon
– Natural gas: 1,030 BTUs per cubic foot
– Electricity: 3,413 BTUs per kilowatt-hour

To compare the cost per unit of heat, you’ll need to factor in the current prices for each fuel in your local area. These prices can fluctuate based on market conditions, taxes, and other factors, so it’s essential to stay up-to-date on the latest pricing information.

Calculating the Cost per Million BTUs

how to calculate propane versus oil heat

Once you have the BTU values and fuel prices, you can use the following formula to calculate the cost per million BTUs for each fuel:

Cost per million BTUs = (Cost per unit) x (BTUs per unit) / 1,000,000

For example, let’s say the current price of heating oil is $3.50 per gallon, and the price of propane is $2.80 per gallon. Using the formula, we can calculate the cost per million BTUs for each fuel:

Heating oil:
Cost per million BTUs = ($3.50 per gallon) x (138,690 BTUs per gallon) / 1,000,000 = $19.61 per million BTUs

Cost per million BTUs = ($2.80 per gallon) x (91,500 BTUs per gallon) / 1,000,000 = $25.62 per million BTUs

This comparison shows that, in this example, heating with oil would be more cost-effective than heating with propane, based solely on the fuel prices and BTU values.

Factoring in System Efficiency

However, the efficiency of the heating system is another crucial factor to consider when comparing the cost of propane versus oil heat. Heating systems have an Annual Fuel Utilization Efficiency (AFUE) rating, which represents the percentage of the fuel’s energy that is converted into usable heat.

Typically, propane heating systems tend to be more efficient than oil-fired systems. Propane furnaces and boilers can have AFUE ratings of up to 98%, while oil-fired systems generally max out at around 95% efficiency.

To account for system efficiency, you can adjust the cost per million BTUs calculation as follows:

Adjusted cost per million BTUs = (Cost per million BTUs) / (System Efficiency)

For example, if the medium-efficiency oil system has an AFUE of 85%, the adjusted cost per million BTUs would be:

Adjusted cost per million BTUs = $19.61 / 0.85 = $23.07 per million BTUs

Comparing this to the propane system with a 95% AFUE, the adjusted cost per million BTUs would be:

Adjusted cost per million BTUs = $25.62 / 0.95 = $26.97 per million BTUs

This shows that the more efficient propane system can offset the higher fuel cost per gallon, resulting in a lower overall cost per million BTUs.

Considering Maintenance and Conversion Costs

In addition to fuel prices and system efficiency, the cost of maintenance and any necessary system conversions should also be factored into the equation.

Oil-fired systems typically require annual cleaning and servicing, which can cost between $125 and $150. Propane systems, on the other hand, generally do not require annual cleaning, reducing the maintenance costs.

Furthermore, the cost of converting from an oil-fired system to a propane system can be significant. This may involve adding a gas line, updating appliances, installing a chimney liner, and removing the old oil tank. These conversion costs can range from several hundred to several thousand dollars, depending on the specific requirements of your home.

Putting It All Together

To make a comprehensive comparison between propane and oil heat, you’ll need to consider the following factors:

  1. Fuel prices and BTU values
  2. Heating system efficiency (AFUE ratings)
  3. Maintenance costs
  4. Conversion costs (if applicable)

By using the formulas and data provided in this guide, you can calculate the true cost of heating with propane versus oil, allowing you to make an informed decision that best fits your home’s needs and your budget.

Remember, the cost of heating can vary significantly based on your location, the size of your home, and other factors. It’s always a good idea to consult with a professional HVAC contractor or energy specialist to get a personalized assessment and recommendation for your specific situation.