HVAC Equipment
Heating, Ventilation, and Air Conditioning (HVAC) equipment helps to control air temperature,
humidity levels, and air quality in a building or house. A well-maintained HVAC system helps
also helps to keep a home free from mold. The products that are usually used in a central heating and
cooling system are boilers, central air
conditioning, furnaces, heat pumps,
radiant heat systems, and wood furnaces.
Here is a brief overview of each.
Boilers
Furnaces that heat water are called "boilers". Boilers burn oil, natural gas or propane.
The hot water is distributed (as liquid water or steam) through pipes to heat
living spaces in a house or building. Boilers are controlled by thermostats, which are used to set
a specific temperature for the water. Modern boilers are small and highly efficient, and can reduce
fuel and energy bills by up to 30% (when compared to boilers made 20+ years ago).
Central Air Conditioners
Central air cools your home and reduces humidity levels. It transfers heat from inside the home to
the outside and leaves conditioned and cooled air to be re-circulated inside the house. An air
conditioner has a compressor that pumps coolant or refrigerant back and forth to gather heat and
moisture from inside the house. Warm air from inside blows over the cooling coil connected to
the compressor and is pumped back into the house as cool air.
Furnaces
Warm-air furnaces heat your home in winter and the ductwork that they use
may also form an integral part of your central air conditioning
system in summer. Gas, oil or propane is combusted in a burner. The heat that is produced passes
through a heat exchanger where it is transferred to the air distribution system. The ductwork in the
house carries the conditioned air all over the house. The furnace flue discharges carbon dioxide
and water vapor outdoors.
Heat Pumps
Heat pumps are used to both heat and cool a space. Hot and cold air is transferred between two
reservoirs. The heat pump can act as an air conditioner by transferring heat from inside to out,
or as a heater by transferring external heat to the inside.
Radiant Heat
A radiant floor heating system heats a room or house by heating the floor. Radiant heat transfers
about 60% of its heat to radiate directly through the floor, unlike conventional warm-air furnaces,
boilers, and heat pumps, which transfer most of their heat to the air. With radiant heat, the air
temperature is cooler, but people still feel warm and enjoy a more consistent sense of comfort than
they do from hot air blowing in from vents or heat rising from radiators. Radiant heating systems
transfer heat to the floor through sub-floor electric mats or plastic tubes filled with water.
Wood Furnaces
A wood or coal-fired furnace burns wood or coal in a sealed firebox and heats an exchanger. A
blower forces air over the exchanger and through ducts into the living space. Wood burners have a
cabinet or jacket, a firebox, blower, and access doors for stoking and cleaning. A small blower
fans the fire when heat has to be increased. Combination wood furnaces have a gas or oil burner or
electric elements as a back up.
