Your Forced-Air Heating System: Know How It Works?
Most homes in the Cincinnati area use forced-air systems for heating. Once installed in the home, a furnace, heat pump or furnace-heat pump combination, also known as a hybrid or dual-fuel system, works simply and efficiently to deliver conditioned air, making the home very comfortable. Although both furnaces and heat pumps use ductwork to deliver and return the conditioned air, they operate on different principles. How a furnace works When the temperature dips below the set comfort level, a thermostat signals the furnace to open a valve and send natural gas to the burners. The blower starts running at the same time. The electronic ignition lights the burner in the combustion chamber. This heats the air that’s moving through the heat exchanger. The warmed air is then pushed into the hot-air plenum, and the ductwork delivers heated air to the various rooms in the home. Cooler air is then sent back to the furnace via the return-air ducts to be heated again and sent back through the home until the desired temperature is reached. The combustion gases are vented through a flue in the roof or through a wall. Although a furnace does a yeoman’s job of keeping your home warm — some models have a nearly 100 percent efficiency — it also tends to dry out the air. This can cause your skin to become drier. Some people develop bloody noses, static electricity can become more prevalent, and the prized wood trim in your Cincinnati home can even become cracked. Dry air also feels cooler than warm air, and you may be tempted to turn up the thermostat. A sound counteractive measure is installing a whole-house humidifier, which can keep the humidity in your home at an ideal 40 to 50 percent, instead of a very uncomfortable 20 to 25 percent. How a heat pump works An air-source heat pump, which uses electricity, has a compressor and two coils made of copper tubing — one outside the home and the other inside. Liquid refrigerant in the outside coil extracts heat from the air and evaporates, becoming a gas. The indoor coil releases the heat from the gas as it returns to a liquid state. As with a furnace, the warmed air is then distributed throughout the home via a duct system. A heat pump is a highly efficient forced-air system and can deliver as much as three times more heat energy than it consumes. Heat pump technology has steadily improved over the years, and many newer models can remain efficient at very cold temperatures and do not need to be coupled with a furnace in a dual-fuel or hybrid system. If you’re considering a heat-pump system, talk with your HVAC contractor to determine whether you can have a stand-alone heat pump, or a hybrid or dual-fuel system is a better choice. Alternatives to traditional systems Although furnaces and heat pumps are most frequently chosen here in the Cincinnati area, some homeowners opt for high-efficiency alternatives. A ductless mini split is often chosen for additions or unheated vacation homes because, as the name implies, it requires no ductwork. A geothermal heat pump operates on the same principle as an air-source heat pump, but instead of extracting heat from the air, it extracts heat from the ground. Are you shopping for a forced-air heating system? To learn more about heating your home, contact Apollo Home Heating, Cooling & Plumbing. We’ve served homeowners in the Cincinnati area since 1910. Image via Shutterstock.com