Air
conditioning includes both the cooling and heating
of air. It also cleans the air and controls
the moisture level. An air conditioner is able
to cool a building because it removes heat from
the indoor air and transfers it outdoors. A
chemical refrigerant in the system absorbs the
unwanted heat and pumps it through a system
of piping to the outside coil. The fan, located
in the outside unit, blows outside air over
the hot coil, transferring heat from the refrigerant
to the outdoor air.
Basic
Operations
Most air conditioning systems have five mechanical
components:
Most central air conditioning units operate by
means of a split system. That is, they consist
of a "hot" side, or the condensing unit-including
the condensing coil, the compressor and the fan-which
is situated outside your home, and a "cold"
side that is located inside your home. The cold
side consists of an expansion valve and a cold
coil, and it is usually part of your furnace or
some type of air handler. The furnace blows air
through an evaporator coil, which cools the air.
Then this cool air is routed throughout your home
by means of a series of air ducts. A window unit
operates on the same principal, the only difference
being that both the hot side and the cold side
are located within the same housing unit.
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The
compressor (which is controlled by
the thermostat) is the "heart" of the
system. The compressor acts as the pump, causing
the refrigerant to flow through the system. Its
job is to draw in a low-pressure, low-temperature,
refrigerant in a gaseous state and by compressing
this gas, raise the pressure and temperature of
the refrigerant. This high-pressure, high-temperature
gas then flows to the condenser coil.
The condenser coil is a series of piping with
a fan that draws outside air across the coil.
As the refrigerant passes through the condenser
coil and the cooler outside air passes across
the coil, the air absorbs heat from the refrigerant
that causes the refrigerant to condense from a
gas to a liquid state. The high-pressure, high-temperature
liquid then reaches the expansion valve.
The
expansion valve is the
"brain" of the system. By sensing the
temperature of the evaporator, or cooling coil,
it allows liquid to pass through a very small
orifice, which causes the refrigerant to expand
to a low-pressure, low-temperature gas. This "cold"
refrigerant flows to the evaporator.
The
evaporator coil is a
series of piping connected to a furnace or air
handler that blows indoor air across it, causing
the coil to absorb heat from the air. The cooled
air is then delivered to the house through ducting.
The refrigerant then flows back to the compressor
where the cycle starts over again. |
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Heat
Pumps keep your home or business warm in the winter
and perfectly cool in the summer. In the winter
the heat pump captures the heat that is always
present in the outside air - even in the coldest
of weather - and pumps back indoors. In the summer,
it's an air conditioner, pulling the heat out
and releasing it outside. |
Your
central air conditioning system consists of two
parts. An outdoor unit and an indoor unit. The
air handler is the indoor unit that circulates
conditioned air throughout your home. An air handler
paired with an air conditioner circulates cool
air throughout your house during the summer months.
When an air handler is matched with a heat pump,
it works all year long, circulating cool air in
the summer, and warm air in the winter. The air
handler consists of a coil and an air blower. |
| Consider
a packaged gas/electric unit providing you with
electric cooling and gas heating. In warm weather,
it's an all-electric, high efficiency air conditioner.
In cold weather, it's a two-stage natural gas
or propane gas furnace, giving you the best of
both energy worlds. With heating, cooling and
air handling functions in one unit, a single package
gas/electric may be the answer for you. |
