In many homes around the world, a boiler is essential. A boiler can provide heat and even hot water to your home, that is, if you have a "combi" (short for combination) boiler.
Highly efficient boilers will save you money on your bills, but to go beyond basic efficiency, it's also important to understand the different options available to you and what they mean for your application, environment, and budget.
Below we have compared each type of boiler fuel: natural gas, propane, oil, and electricity, so you can see what fuel choice is right for you.
Geography: Depends on proximity to pipeline, but usually readily available.
Price: On average, the least expensive fuel (depending on proximity to pipeline).
Effect on Environment: Cleaner than oil, low amounts of greenhouse gases.
Energy Value: 850-1,050k BTU/ft.
Areas at the end of the pipeline, such as the Northeast, usually have higher prices for natural gas since the gas has to be transported by a truck while in a liquid state. Gas-fired boiler emissions contain low values of carbon and high values of hydrogen.
The combustion of natural gas results in a low amount of greenhouse gas emission and is found to be a clean fuel in comparison to oil. In general, having a high efficiency gas boiler means you have a unit with fuel that is readily available, burns cleanly, and is usually less expensive than oil or electricity.
Geography: Widely available
Price: Typically costs more than natural gas, but still relatively inexpensive
Effect on Environment: Cleaner than oil, not a greenhouse gas
Energy Value: 91k BTU/gallon
Propane is similar to natural gas in that it is simple and economic, however, since it's a liquid, the energy content of propane is measured in gallons instead of cubic feet. It is generally carried and delivered to the usage point with the help of pressurized gas containers.
Although propane is not a very sustainable form of fuel, it is a fairly clean fuel - it produces fewer emissions than other carbon energy sources including oil and gasoline, and it is not considered a greenhouse gas. Many gas-fired boilers can accept either natural gas or liquid propane as fuel by using an appropriate conversion kit.
Geographic: Needs to be transported
Prices: Often more expensive than gas or propane, cheaper than electricity
Effect on Environment: Cleaner than burning wood or coal, more CO2 than natural gas Energy Value: 139k BTU/gallon
Oil-fired boilers usually burn fuel oil which has to be delivered by truck, and the costs of transporting oil are not cheap. However, high efficiency oil boilers are a popular choice in areas of the country that have limited access to natural gas. Burning oil is a clean and ash-free combustion process.
Oil fuel emissions usually consist of more carbon content than natural gas, but less carbon content than solid fuels such as coal, which means there is less emission of carbon dioxide.
Geographic: Widely available
Prices: Usually very expensive
Effect on Environment: Depends on source of electricity
Energy Value: 3,412 BTU/kwh
Electric boilers are popular for being clean, quiet, compact, easy to install and easy to replace. These types of boilers can be used as good alternatives for customers who are restricted by emissions regulations.
They are the most expensive form of boiler fuel, but they are also the most efficient. These systems are very useful if there is not a gas or oil supply nearby. Electric boilers do not utilize a fire box, and are therefore safer than oil and gas boilers. Electric boilers are considered cleaner than gas or oil-fired boilers because there is less condensation and fewer contaminants.
Boilers, like any other product, can make a significant impact on your energy footprint - whether or not that footprint is small or large is up to you.