Feel the heat
Furnaces are very often used to generate heat in buildings. Regardless of the type of climate you live in, most modern HVAC systems include air conditioning as well as heating capabilities. However, in homes that do not have a centralized HVAC system, furnaces typically function independently.
Types of Furnaces
While there are many different types of furnaces, several variations appear more commonly in modern homes than others. For example, fireplaces can be considered a type of furnace, technically speaking. Though they can be relied upon to provide supplemental heat, more often than not their function is primarily aesthetic rather than practical.
Central warm-air furnaces, steam or hot-water furnaces, reverse cycle systems and floor or wall furnaces comprise the majority of heating systems seen in today's residential and industrial buildings. Each of them relies on different means of generating and distributing heat.
A central warm-air furnace uses fuel or electricity to create heat in a central combustor or resistance unit. Circulation can be powered by gravity-based or forced-air systems. Gravity-based heat distribution systems rely on the scientific principle that warm air rises, while forced-air systems physically push warm air through ducts and vents into rooms.
Hot-water furnaces use boilers to supply either steam or hot water to baseboard heaters, heating pipes or radiators. Alternately, some steam furnaces use radiant heating principles to distribute heat via inlaid pipes in the floor. This approach is known as radiant floor heating.
Reverse-cycle systems are, essentially, the opposite of air conditioning. Rather than cooling off warm indoor air, these systems heat up cool air and distribute it through the building.
Finally, floor or wall furnaces use ductless combustors to warm the air. Since they are built right into the walls or floor of the room they are intended to heat, these systems typically deliver heat through built-in registers.
Maintain Your Furnace
If your furnace delivers heat through a system of ducts and vents, you should have your ducts cleaned from time to time and pay close attention to the condition of your furnace filters and thermostat. Furnace filters are used to remove harmful particles from the warm air that's pumped into your home, but when they become clogged, they must be cleaned or replaced. Dirty filters not only make your furnace less able to heat your home efficiently, they can also make the furnace work harder than it should and cause wear or even damage to it.
Thermostats are used to control the temperature of your home. If they malfunction or their calibration is off, you will end up overheating your home. This can send your home energy bill skyrocketing, so if you notice any difference between the temperature of the room and the temperature you set your thermostat at, get it repaired at once.