AIR CONDITIONING SYSTEMS
Today's best air conditioners use 30% to 50% less energy to produce the same amount of cooling as air conditioners made in the mid 1970's. Even if your air conditioner is only 10 years old, you may save 20% to 40% of your cooling energy costs by replacing it with a newer, more efficient model.
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.
Air Conditioning units are designed to
cool your home by absorbing heat in an evaporator
coil mounted on your furnace or air handler. This
coil is connected by refrigeration lines to your outdoor
air conditioner. The more heat the air conditioner can
discharge from the house for the smallest amount
of electrical usage isknown as the Seasonal Energy
Efficiency Ratio or S.E.E.R. The higher this number,the lower the operating cost. (MILES
PER GALLON ON YOUR ELECTRIC METER) S.e.e.r.'s start at 13 and go up to 18+.
The degree of air coming out your grilles will be the same no matter if the s.e.e.r.
is 13 or 18+. The higher s.e.e.r. equipment just does
To determine which s.e.e.r. is best for
you, you will need to first have to look at your current electric usage ( how cold you
like your house ), how much longer you plan
on living in your home, and of course your budget.
And as you can probably already imagine, the higher
the s.e.e.r. the more of an investment you'll have
to make. If you plan on living in the home for quite
awhile, the higher s.e.e.r. equipment is the way to
go. You will recoup your money in the long run.
The majority of systems installed prior
to 1992 were 10 s.e.e.r. or lower. Potential
energy savings may vary depending on your personal
lifestyle, system settings, equipment maintenance,
local climate, actual construction and installation of
equipment and duct system. If your current system
is 10 s.e.e.r. or lower you can compare
it to higher s.e.e.r. equipment and receive a lower
Most air conditioning
systems have five mechanical components:
- a compressor
- an expansion valve or metering
- an evaporator coil
- a blower
- a chemical refrigerant
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.
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
which 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.