Forced-air heating is the most widely used heating method in the U.S., offered by many leading furnace brands. According to the U.S. Department of Energy (DOE), upgrading to a high-efficiency forced-air system can boost heating efficiency by up to 11%.
Often referred to as a forced hot air (FHA) system, forced-air heating relies on a furnace to heat and circulate air throughout the home. This system is generally more efficient than boiler-based systems, which heat and distribute water. Forced-air systems can achieve efficiency levels as high as 98.5%, compared to the maximum of 90% efficiency typically seen with boilers.
Energy Star reports that the average annual heating bill for a home is around $600. By switching to a forced-air heating system, you could see an efficiency improvement of up to 8.5%, translating to an average annual savings of $50. Over the potential 30-year lifespan of an HVAC system, this could amount to a total savings of $1,500.
Ray Snesrud, founder and CEO of Water Heaters Now, a plumbing and HVAC company based in Burnsville, Minnesota, agrees: “Forced hot air (FHA) systems are significantly more efficient than electric baseboard heating but fall short when compared to the efficiency of radiant heating systems.”
However, forced-air heating systems may not be the best choice for everyone. They can be noisy, especially if the equipment is located in certain areas of the home, and they require additional maintenance for the ductwork.
Before contacting an HVAC specialist for a quote, it’s important to understand the benefits of an FHA system and how it operates to determine if it’s the right fit for your home.
How Does a Forced-Air Heating System Work?
A forced-air heating system operates using a central heating unit known as a furnace to generate heat. In about 57% of U.S. homes, this furnace uses natural gas as its primary fuel source, according to the Department of Energy (DOE).
An air handler, which is connected to the furnace, utilizes a blower motor to draw heated air from the furnace’s heating chamber. This warm air is then pushed through a network of ducts hidden behind walls, ceilings, and floors, distributing heat throughout the home via supply vents.
The same ductwork used for heating in the winter can also be utilized for cooling in the summer, but you’ll need a central air conditioning system in addition to your furnace.
After circulating through the home, the blower motor pulls the air back in through return vents and recycles it to the furnace for reheating. Some forced-air systems are equipped with mechanical ventilation systems that draw fresh air from outside, heating it before it is circulated indoors. These systems often have separate vents and blower motors to introduce this fresh air into the ductwork.
Is Forced-Air Heating Energy-Efficient?
Forced-air heating systems can achieve up to 98.5% efficiency, making them highly efficient. This efficiency is measured by the system’s Annual Fuel Utilization Efficiency (AFUE) rating, which indicates how much energy from the fuel source is converted into heat. The higher the AFUE rating, the more efficient the system.
According to Energy Star, furnaces generally have efficiency ratings 5% to 10% higher than boilers—ranging from 90% to 95%—because furnaces can reach higher efficiency levels.
What Fuel Types Do Forced-Air Heating Systems Use?
Forced-air heating systems can operate on natural gas, electricity, or oil. The best fuel option for you depends on local availability and the cost of these resources.
Electric furnaces can technically reach 100% AFUE, making them the most efficient in terms of fuel conversion. However, electricity is often generated from natural gas or oil at power plants with only 30% efficiency. Unless you’re generating your own electricity through solar panels, electric heating could result in higher costs.
Gas and oil furnaces burn their respective fuels to produce heat, which is then used to warm the air inside the furnace before it’s circulated throughout the home.
Some modern furnaces are hybrid systems that use both gas and electricity. These hybrids can switch to electric power during milder weather to conserve energy. However, gas furnaces are typically preferred in colder climates due to their faster heating capabilities. As Ray Snesrud from Water Heaters Now explains, “Electricity is a less powerful source for heat than gas by a long shot. In cooler climates, a gas FHA [system] is the only economical option.”
Can Forced-Air Heating Be Used for Cooling?
While forced-air heating systems are designed specifically for heating, the ductwork they use can also serve a central cooling system. By installing a central air conditioning unit, you can utilize the same ducts for cooling your home, providing year-round temperature control.
According to Lowe’s, the cost of a central AC condenser ranges from $1,100 to $5,600, depending on the brand, size, and Seasonal Energy Efficiency Ratio (SEER). This price does not include installation labor.
Combining your heating and cooling systems by using shared ductwork can reduce installation costs. For homes that previously used a boiler and hot water heating system, this would avoid the additional expense of installing new ductwork for air conditioning.
What Are the Pros and Cons of Forced-Air Heating?
Forced-air heating systems are popular in the U.S. due to their high efficiency and the ability to introduce fresh outdoor air through built-in ventilation systems. Unlike boiler systems, which require windows or doors to be opened for fresh air, forced-air systems can ventilate the home more effectively.
However, there are some drawbacks. Access to natural gas lines is necessary, and the system can be noisy due to the blower fan, which can reach 20 decibels—comparable to the sound of a ticking watch.
Pros of Forced-Air Heating:
- 8.5% to 9% more efficient than boilers
- Potential lifetime savings of $1,500 compared to boilers
- Can introduce fresh outdoor air instead of recirculating indoor air
- Ductwork can be used with central air conditioning for cooling
- No baseboards or radiators take up living space, unlike hot water and steam boilers
Cons of Forced-Air Heating:
- Blower fan noise can be disruptive
- Requires additional equipment for cooling
- Occasional duct cleaning may be needed to remove allergens and contaminants
- Between 20% and 30% of conditioned air in ducts may be lost due to leaks, leading to higher energy bills
How Much Maintenance Do Forced-Air Heating Systems Require?
Forced-air heating systems require regular maintenance, similar to other heating systems. Routine DIY tasks include changing air filters to prevent debris buildup and reduce strain on the blower motors. Keeping air filters clean can lower energy consumption by up to 15%, according to the DOE.
It’s also advisable to have a professional tune-up performed regularly to ensure moving parts are properly lubricated and any minor wear is addressed before it becomes a larger issue.
As Snesrud advises, “Changing the filter once a month for the 1-inch-wide models [of air filters] is good, whereas the 4-inch models need to be only changed twice a year. For preventative maintenance, a biannual checkup should be done by a professional. Often small adjustments in pressure settings can prevent a major repair bill.”