If you want to install a new furnace, you have numerous factors to consider such as the brand, size, and features, among others. Some of these factors are more critical than others. Below are the three major factors that you should give priority over others.
The British thermal unit (BTU) of a furnace is a measure of the heat output of the furnace. A higher BTU means more heat output than a lower BTU. You should know how much heating your house requires and buy a furnace that will provide the needed heat. You need to size the furnace correctly. An undersized furnace won't heat your house adequately, and an oversized furnace will overheat your house; both of them will waste energy.
Determining how much heating a house requires is known as load calculation. The calculation depends on multiple factors such as the size of the home, the local climate, the number and configuration of the rooms, and the number of windows and doors, among others. A furnace technician will help you with the calculations.
The annual fuel utilization efficiency (AFUE) rating is a measure of the efficiency of a furnace. The AFUE is the percentage of fuel that a furnace converts into heat. For example, if a furnace consumes 1,000 BTUs of energy and outputs 900BTUs of energy, then the furnace has an AFUE (or efficiency) of 90%. High AFUE rating means high furnace efficiency.
If you buy a furnace with a low AFUE rating, you will be wasting a lot of energy in the name of heating your house. The AFUE rating can be as low as 56% (for older systems) and as high as 98.5% for modern systems. Look for a furnace with an AFUE rating of at least 80%; anything below that is low efficiency.
Lastly, you also need to consider the type of fuel you will use to power up the furnace. Most furnaces use gas, electricity, or oil. All fuel types have their pros and cons that you should carefully evaluate. For example:
- Gas furnaces are relatively expensive to install, but the fuel is relatively cheap, and gas furnaces have high efficiency.
- Electric furnaces tend to be small and inexpensive, but electricity costs can be expensive, depending on your area.
- Though oil furnaces are not very common, they produce considerable heat and are suitable for areas that experience extreme winters. Note that oil furnaces have the additional cost of the oil tank installation.
Your residential heating maintenance technician can help you with further exploration of all these types of fuel for heating. In many cases, you find that one fuel type is best for an area due to the local climate, utility costs, and other location-based factors.