Certain purchases homeowners only have to make once or twice in their time in the house. A furnace is one of them. Therefore, homeowners probably don't keep up on how to make this all-important purchase. And it is, indeed, all-important in a cold snap when you need to keep your house habitable.
If you're in the market for a new furnace, keep in mind these important considerations.
A furnace needs to have a big enough capacity to heat your home adequately. If the furnace is too small, you'll be left with cool rooms instead of cozy. Buying an oversized furnace isn't the answer, though, because it will heat rooms too quickly. It'll, therefore, cycle on and off, which wears the furnace out more quickly.
The general rule for sizing a furnace involves knowing what climate zone you live in and the size of your house. A mathematical equation will determine the number of BTUs you need to heat your house. However, other factors play into that equation, including insulation and the orientation of your house. Consider asking your HVAC specialists to perform that analysis for you.
Most furnaces are either natural gas- or electric-fueled. If you have a natural gas line, you probably have a gas furnace. You should probably stick with that fuel type because electric is a little more expensive to run. If you have an electric furnace, you probably need to stick with that, too. An alternative is oil, but that's typically suitable for homeowners with limited access to electricity.
With gas furnaces, which represent the most popular type, you have three kinds of furnaces to choose from. The old-school style is the single-stage furnace. This furnace is either on or off, meaning it's heating at full capacity or not at all. These furnaces are best for mild climates.
Two-stage furnaces have two heating capacities. The gas can flow in low or high. Your home's thermometer signals what level is needed to heat your home. The modulating furnace is the most precise for the regulation of temperature. It operates in one percent increments. These furnaces are ideal for homes in cold climates.
As Home Tips points out, a gas furnace's fuel efficiency will dictate how expensive it is to run. You'll see it as a rating called AFUE, which is actually a percentage related to how much of the gas is converted into usable heat. So, a furnace with an 85-percent rating only converts 85 percent of the gas into usable heat, which means you spend more in fuel trying to heat your home.
Talk to your local furnace replacement contractor about the ideal furnace for your needs.