Home Heating Systems Explained

home heating systems
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Most homes are constructed with a heating system, even if it's just an old wood burning fireplace. We generally don't give a lot of thought to how our houses are heated until we set out to buy a home. At that point, home heating systems can sometimes make or break that sale.

Here are some of the most common home heating systems and how they work:

Furnaces

A furnace draws air from the house into a ductwork system, taking it to an area where it is warmed before being delivered back to living spaces. Newer furnaces use blowers to recirculate the warmed air. A furnace may be fueled with gas, electricity, oil, or even coal or wood. Circulating air is drawn through a filter that helps rid the house of dust and other particles.

Here are how different types of furnaces operate:

  • Gas and oil furnaces have a pilot light that warms a heat exchange unit, which in turn warms the air before it is circulated back through the house.
  • Electric furnaces use heating strips, or elements, to warm the air.
  • Wood or coal furnaces have a sealed firebox where the fuel is burned, and a heat exchanger where air is warmed before delivery.

Gas and oil furnaces have a flue where exhaust gases vent to the outside. Tanks for oil furnaces are sometimes buried and if they leak, become an environmental hazard that can be costly to remediate.

Metal vents bring warmed air into the living area and are usually found in floors or walls with temperature controllable through an adjustable eye-level thermostat.

Electric Heat Pumps

Heat pumps work by shuffling heat from one place to another. They also serve as air conditioners during warm weather.

Heat pumps extract warmth from outdoor air, from ground or surface water, or from the earth. The air is warmed more by the system if necessary, then circulated through the house.

You'll find metal vents and filters similar to those used for forced air furnaces. The thermostat may appear similar, but will also include controls for air conditioning. The outdoor unit usually states "heat pump" on its label.

Radiant Baseboard Heat

Baseboard heaters are often visible as long, metal units with electrical elements inside. Each unit has its own control, which may be marked in increments from low-to-high, but will not show the room's current temperature.

You might see baseboard heaters used as a home's sole source of heat, or for supplemental heat in cooler rooms or rooms that were difficult to outfit with duct work. They are typically more expensive to operate than furnaces.

Radiant Ceiling or Floor Heat

Radiant systems warm objects in much the same way as the sun does. No blowers are used.

Electric radiant elements are installed in floors or ceilings. In some cases, each area has a dial control similar to the ones that operate baseboard heating units. Heating elements can also be installed in walls, but that location is less common.

"Hydronic heating" is another type of radiant heat, where hot water flows through tubes under the floor or through units that resemble baseboard heaters. A hydronic system might be installed in ceilings and is sometimes used under concrete in driveways to keep snow and ice from accumulating. Hydronic heating systems include a boiler that warms the circulating water.

Space Heaters

Portable space heaters that are electric or fueled by gas or kerosene should not be used to qualify an area as heated living space.

If a gas space heater is permanently attached to a wall, it allows an area to be counted as heated living space, providing other qualifications are met.

A home inspector can usually offer information and advice about all types of heating appliances beyond these basics.

This article is edited by Elizabeth Weintraub, homebuying expert at TheBalance. At the time of writing, Elizabeth Weintraub, CalBRE #00697006, is a Broker-Associate at Lyon Real Estate in Sacramento, California.