How to Compare Propane Furnaces


It’s possible that installing a heater in your house that runs on liquid propane gas might be one of the best investments you make in terms of energy efficiency. You will be better able to choose the kind of furnace that is most suited to your specific requirements if you have a solid understanding of the factors that influence how efficiently a furnace converts propane into heat, as well as how the furnace distributes that heat throughout your home.

Heat Output

Referring to the heat-output ratings of a propane furnace is the most straightforward approach to evaluate the heating capabilities of different models. These values are expressed in British Thermal Units, and they indicate the total amount of heat that may be produced by the furnace in one hour. Output ratings are typically in the range of roughly 40,000 to 120,000 BTU per hour on average. It is critical to choose a furnace that has a capacity that is proportionate to the area that has to be heated. A furnace that is too tiny to appropriately heat the room will not run efficiently, while a furnace that is too huge will not heat the space sufficiently.


There is a broad range of efficiency across different types of furnaces, and the efficiency rating of a propane furnace indicates how much of the heat energy contained in the fuel the furnace is able to convert into useful heat. A furnace with a rating of less than 80 percent is considered to have a poor efficiency, whereas a furnace with a rating of between 90 and 95 percent is considered to have a high efficiency, and a very high efficiency furnace has a rating of 95 percent or more. If you upgrade to a high-efficiency propane furnace, you may see a significant drop in your monthly fuel costs. However, if you live in an area that does not experience particularly harsh winters, the difference between a high-efficiency furnace and a very high-efficiency unit may not be as pronounced.

Sealed Combustion

For a heating system that does not have a sealed combustion chamber, the air from the inside of the building is sucked into the furnace to provide fuel for the heating flame. The air that is being used for combustion has already been heated, and this air that has been heated prior to being used for combustion is being wasted since it is being sent up the chimney in the form of exhaust fumes. This sort of system is inefficient. Because it receives combustion air from the outside and discharges exhaust gases right back outside, a sealed-combustion propane furnace may be substantially more efficient than a traditional one.


The location in your home where you want to put the propane furnace will help you identify which configuration is the optimal selection for your needs. The basement is the typical location for the installation of an upflow furnace, which has the blower directing the warm air upwards. When the unit has to be put in an attic, it is recommended to use a downflow furnace, which pushes the air downward from above. When there is a restriction on the amount of vertical installation space available, it is advisable to use a horizontally constructed unit. This kind of unit has the blower positioned behind the heat exchanger and flows air through the unit in a horizontal direction.