When it comes time to get a new furnace, you’re faced with many choices. You can replace what you have with something similar or upgrade to something more efficient. Here’s your guide to understanding the differences between what’s available and what you should consider as you make your decision.

Understanding How Furnaces Work

To better evaluate your options, it’s important to first understand how your furnace works. This will help you understand why some furnaces are more efficient than others and what factors matter in your house.

To heat your home, a furnace must do two things. First, it must generate heat. Then it needs to circulate air from inside your home through the furnace and back out again.

As long as the furnace is generating heat effectively, the most critical function is circulating the air. If anything inhibits that airflow, your furnace will overheat while leaving your home feeling cooler than you want. Additionally, there needs to be enough output vents and return registers to create the circulation needed to distribute the heat around your home.

Start With the Size

Before starting to shop the different options in furnaces, you need to know what size you need. Getting the wrong size will decrease your efficiency, increase your utility costs, and also increase your repair costs.

Furnace sizes indicate their heating capacity, which is measured in BTUs, or British Thermal Units. The more space you’re trying to heat, the more heat your unit needs to produce at a time.

To determine the size you’ll need, start with the square footage of your home. For homes in southwest Michigan, the estimate is 45 to 50 BTUs per square foot. However, there are other factors that’ll influence that size. These may include:

  • The house’s environment
  • Number of windows
  • Height of ceilings
  • Number of occupants

A professional installer knows how to evaluate all the variables to help you find the right size. This is a skill developed through both science and experience, so rely on that rather than trying to guess on your own.

Consider Heating Options

Once you know the heating capacity your home requires from a furnace, it’s time to consider your heating options. Furnaces have two broad categories, fuel-burning models and electric models. Electric furnaces generate heat using an electric resistance element, much like you’d find in a space heater. These are generally better suited for mild climates that don’t get extremely cold weather over the winter.

Most homes in western Michigan use fuel-burning furnaces to keep up with the winter storms prone to blow through. There are several fuel types available, depending on what your home needs. Newer homes in developed areas tend to use natural gas that’s brought to the house through buried lines. However, older homes and those in the more rural areas may use either oil or propane. These have fuel tanks that sit outside the home and require a service to come to refill them.

It’s best to look at what your home is already set up for before selecting a unit. If your home doesn’t have natural gas running to it, you likely don’t want the expense of bringing it in. However, natural gas is more efficient than oil or propane, so you’ll want to use it if it’s available for your home.

Evaluate Efficiency Differences

Natural gas furnaces come in a range of efficiency options. When talking about efficiency, this refers to how much heat is transferred to your home versus what’s lost in the exhaust. By law, the lowest efficiency furnace allowed to be manufactured is 80%. However, you can also get a high-efficiency model that will offer a rating of 90-98%.

These higher efficiency units have a few different features that help improve their rating. First, they usually have modulating burners, which dynamically adjust the unit’s flame based on the heating need. The smaller the flame that’s needed, the less fuel it uses, making it more efficient. Add to that, they normally have two heat exchangers, allowing the circulating air to absorb more heat before the exhaust vents out through the flue.

These units also have variable speed circulating fans or ECMs. The furnace can adjust the speed at which the fan spins based on what’s required in the home. This allows the unit to also use less electricity to run the fan, improving the overall efficiency.

More basic models typically have single-stage burners and fans. You could say they run on high all the time, using more fuel and energy to keep your home comfortable.

Check for Compatibility

If you’re replacing an existing unit in your home, you’ll also want to think about compatibility with the rest of the installed system. If your entire system is in poor condition, this becomes less of an issue because you’ll replace all of it.

However, if you’re trying to reduce your installation expenses, you’ll want to check compatibility with several parts of the system. We already discussed looking at the fuel source available for your home, so start there.

Next, look at your ductwork, and find a unit that’s compatible with what you have. Check to ensure the furnace works with the size of ductwork your home has installed. Next, check the volume of air the unit circulates and ensure the ductwork will handle it properly. This typically means evaluating the number of output vents and the return system.

Finally, check the flue to ensure compatibility. In some cases, the flue may need repair, especially if it runs up a fireplace chimney. If you’re switching to a high-efficiency furnace, you may not need a standard flue because the exhaust is no longer hot when it vents out.

Consider Comfort Options

Once you’ve looked at all the technical parts of the furnace to ensure it’ll work, look at the comfort options. This generally includes noise and humidity control. If you’re sensitive to the noise in your home, look for a furnace that runs more quietly.

Winters around Michigan are typically pretty dry, especially with a furnace running. You may want to consider a furnace option that has a built-in whole-house humidifier. This will help keep your family healthier over the winter, reduce dry skin, and improve your overall air quality.

Think About Cost, Rebates, and Return

Finally, consider the cost of the furnace and its operational cost over time. High-efficiency models will have lower utility costs but are more expensive to install upfront.

However, if you’re considering that high-efficiency model, there are some offers available to help ease the investment. Check with your tax professional for available tax rebates when you upgrade to a high-efficiency model. You may even find manufacturer rebates, depending on the time of year you purchase your unit.

Both standard and high-efficiency furnaces have about the same return when it’s time to sell your home. However, younger homebuyers are generally attracted to homes with higher-efficiency appliances. Therefore, investing in this now may help you sell your home more quickly when you’re ready to move in the future.

People around Three Rivers have trusted Bel-Aire Heating & Cooling to keep their homes and families safe and comfortable for more than 60 years. Our team delivers reliable air conditioning and heating maintenance, repair, and installations, as well as energy audits. Call to schedule your new furnace consultation with one of our expert furnace installers today.

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