Home heating systems are designed to increase the temperature inside a house by tapping thermal energy from a fuel source, then transferring it to living spaces. There are several types of systems used to provide heat in residential homes, and each broad type has more specific variations. Some HVAC systems share components with the home’s cooling equipment, some work independently, and some provide both heating and cooling.
What Is HVAC?
HVAC is an abbreviation for heating, ventilation, and air conditioning. This term is used to describe the overall climate control system within a home, referring to both the heating and cooling equipment.
No matter what HVAC system is installed, the purpose of all heating appliances is to use some type of fuel to warm the interior of a home. Heating systems can use a variety of fuel sources, including natural gas, propane, fuel oil, biofuel (such as wood), solar, and electricity. Some homes have more than one heating system: For example, some additions are heated by different systems than the rest of the house.
Here, learn about the different types of heating systems plus the pros and cons of each to help you decide which option is best for your home.
Forced Air Heating/Cooling Systems
By far the most common HVAC system in modern homes, the forced air system uses a furnace with a blower fan that delivers warmed air to the various rooms of the home through a network of ducts. Forced air systems are very quick at adjusting the temperature of a room, and because air conditioning systems can share the same blower and ductwork, this is an efficient overall HVAC system.
This is based on the square footage of your home, and larger houses will require stronger units that may increase costs. These systems can last up to 25 years before needing replacement units.
Fuel sources: The furnaces that power forced air systems can be fueled by natural gas, propane, or electricity.
Distribution: Air that is warmed by the furnace’s burner or the heating element is distributed through a network of ducts to heating registers in individual rooms. Another system of ducts returns the air back to the furnace through cold-air returns.
• Air filters and humidifiers can be added.
• Highest AFUE (Annual Fuel Utilization Efficiency) ratings of any heating system.
• Combine cooling with heating capability.
• Requires ductwork and space in walls.
• Can create dry, allergen-prone air without filters and humidifiers.
• Heats the air rather than the objects in a room.
In-Floor Radiant Heating Systems
These systems can be either hydronic or electric. Hydronic systems rely on pumping water as the heat source, while electric systems rely on electrical resistant coils built into the floor system to generate heat.
Hydronic in-floor radiant heating involves plastic water tubing which is installed inside a concrete overlay built into the floor or, alternatively, attached to the top or bottom of a wood subfloor. It is quiet and generally energy-efficient. It tends to heat slower and takes longer to adjust than forced air heat, but its heat is more consistent. While maintenance can be difficult to reach the hidden pipes, in-floor radiant heating units should last for several decades.
Radiant heating is different from forced air heat in that it heats objects and materials, such as furniture and flooring, rather than just the air. Most whole-home radiant systems distribute heat via hot water heated in a boiler or hot water heater. However, boiler-based systems cannot be combined with air conditioning.
There are also in-floor systems that use electrical wiring installed under flooring materials, typically ceramic or stone tile. These are less energy-efficient than hot water systems and are typically used only in small rooms such as bathrooms. They primarily heat the floor in such a way as to keep your feet warm, but not so much the room itself.
Fuel sources: Hot water tubing systems are usually heated by a central boiler, which can be fueled by natural gas, propane, or electricity. Hot water also can be provided by solar hot water systems, which are commonly used to supplement fuel-based systems.
Distribution: In-floor systems are usually distributed by hot water flowing through plastic tubing.
• Comfortable, evenly distributed heat.
• Energy efficient with use of boilers.
• Can be solar-powered.
• Slow to heat up during temperature changes.
• Expensive to install.
• Maintenance of hidden piping is difficult.
Heat Pump Heating Systems
The newest home heating (and cooling) technology is the heat pump, which uses a system similar to air conditioners to extract heat from the air and deliver it to the home via an indoor air handler. Standard home systems are air-source heat pumps that draw heat from the outdoor air. There are also ground-source, or geothermal, heat pumps that pull heat from deep in the ground as well as water-source heat pumps that rely on a pond or lake for heat.
A popular type of air-source heat pump is the mini-split, or ductless, system. This has a relatively small outdoor compressor unit and one or more indoor air handlers that are easy to add to room additions or remote areas of a home. Many heat pump systems are reversible and can be switched to air conditioning mode in the summer. Heat pumps can be energy efficient, but they are suitable only for relatively mild climates; they are less effective in very hot and very cold weather. These systems usually last 15 years or more.
Best for: Heating and cooling without ductwork in mild microclimates.
Fuel sources: Heat pumps are usually powered by electricity, although natural gas models are also available.
Distribution: Heat (and cooling) are provided by wall-mounted units that blow air across evaporator coils made from copper or aluminum, which are linked to an outdoor pump that extracts or absorbs heat from the outdoors.
• Heating and cooling can be combined without needing ductwork.
• Precise temperature control for each room with quiet fans.
• Best suited for relatively mild climates.
• Distribution of hot or cold air is limited.
• Each unit must be controlled individually from separate rooms.
Electric Resistance Heating Systems
Electric resistance systems like baseboard heaters are a popular option for supplemental heating in finished basements, home offices, and seasonal rooms like three-season porches and sunrooms. These heaters are not commonly used for primary home heating systems, mostly due to the high cost of electricity.
Like in-floor radiant heat, radiant electric heaters warm the objects in the room rather than just the air. Electric heaters are relatively easy and inexpensive to install and they require no ductwork, pumps, air handlers, or other distribution equipment. The units are inexpensive, have no moving parts, and require virtually no maintenance.
There are two main types of baseboard heaters: convection (traditional) and hydronic. Convection is a metal rod with fins that, as electricity is applied, the rod and fins heat and give warmth to the room. Hydronic is a metal tube filled with a liquid that is heated when electricity is applied and holds the heat longer, but it takes longer to heat up and is 3-4 times more expensive than convection units.
In addition to conventional baseboard heaters, there are electric radiant heaters that heat with radiation. These typically are installed near the ceiling and are directed toward the room occupants, providing more focused heat than you get with baseboard units. Radiant heaters also are more energy efficient than baseboard units.
Best for: Supplemental heating in less-used rooms.
Fuel sources: Electric resistance systems wired into the home’s electrical circuits, using the home’s electricity.
Distribution: Baseboard heaters use natural convection to circulate heat throughout the room. Wall-mounted heaters and many specialty heaters (like toe kick heaters) usually have internal fans that blow out heated air.
• Versatile; can be installed anywhere with an electrical circuit
• Silent operation without fans
• No ductwork or major installation needed
• Expensive to operate
• Use a lot of electricity; may exceed available electrical capacity
Hot Water Baseboard Radiator
Best for: Radiant heating with a smaller system than traditional radiators.
Another more modern form of radiant heat is a hot water baseboard system, also known as a hydronic system, which also use a centralized boiler to heat water that circulates through a system of water pipes. This water flows to low-profile baseboard heating units that radiate the heat from the water out into the room via thin metal fins surrounding the water pipe, typically made of carbon steel. Hot water baseboard heaters can last for several decades, and typically cost between $450 and $1,200 to install new or replace old units.
Single Purpose Systems
These systems use separate appliances, each with a singular task. Either a hot water heater or a boiler handles all the heated water necessary to power the radiant baseboard heating needs. Meanwhile, a separate hot water heater takes care of the household hot water usage. You may need to purchase two different hot water heaters if you choose a single purpose system. The one used to drive a radiant floor heating system must be rated to do so.
Dual Purpose Systems
A dual purpose system relies on only one water heater to supply both the hot water requirements for the home and the warm water needed for the radiant baseboard heating. Even if only part of the home uses radiant floor heating, a dual system depends on a single water heater for hot water and radiant heating. A conventional furnace or a boiler might handle the heating needs of the rest of the home.
Fuel Sources: Boilers for hydronic systems can be fueled by natural gas, liquid propane (LP), fuel oil, or electricity. They can also be aided by solar heating systems.
Distribution: Hot water is heated by a boiler and piped to “fin-tube” baseboard units mounted along walls. The fins increase the surface area of heat dissipation for efficiency. Heat is distributed by natural convection: Heated air rises from the baseboard unit, while cold air falls toward the unit for heating.
• Excellent energy efficiency and requires little maintenance to perform well.
• Quiet operation.
• Temperature can be precisely controlled.
• Must remain unobstructed; can limit furniture placement or window coverings.
• Cannot be combined with air conditioning.
• Slow to heat up; pipes are at risk of freezing if system goes out.
Choosing a Home Heating System
When choosing a new heating system for your home, it’s important to weigh the pros and cons of each option and determine what type of heater suits your needs. For example, in-floor radiant heating is a great option for those living in coastal microclimates that don’t need to heat their home in cooler temperatures for several months straight. In less temperate microclimates, forced air heating or radiators can provide more consistent and comfortable temperatures through the winter.
For Further Reading:
• Several home heating systems type are described in various articles available at the U.S. Department of Energy. The link is: https://www.energy.gov/energysaver/home-heating-systems
• Smarterhouse.org describes several heating systems, both conventional and alternative, in the article at: https://smarterhouse.org/heating-systems/types-heating-systems
• Forbes Home has published a detailed accounting of home heating systems at: https://www.forbes.com/home-improvement/hvac/home-heating-systems/