What is Air ConditionerCondenser?

Types of air conditioner
condenser
AC condenser units are grouped
according to how it rejects the
heat to the medium (surround
air). Here are a few condensers
units.
Air cooled condenser
Earth cooled condenser
(Geothermal Heat Pumps)
Water cooled condenser
Combination of air and water
cooled condenser (Evaporative
condensers)
Air cooled condensers are mostly
used in residential air
conditioner units and
commercial air conditioning unit.
The Air Cooled Condenser
The air conditioner parts that are
located beside residential are an
air cooled condenser.
Air cooled condenser use
outdoor air as a place to reject
the heat absorbs by the air
conditioner units. The condenser
also has parts that help with heat
reject.
Here are some of the condenser
parts:
Condenser fan blade
Condenser motor
Condenser coils
Air conditioner compressor is
within the condenser unit, but it
does not help with heat
rejection!
The condenser fan is mounted
with the air cooled condenser.
The condenser fan primary
purpose is to increase condenser
unit ’s capacity to reject heat.
Air cooled condenser come into
two types:
Fin and tube condensers
Plate condensers
The Water Cooled Condensers
The water cooled condensers
reject the heat absorbs by air
conditioner system to the water.
The water has to be clean,
noncorrosive, and at certain
temperature. This water has to
be treating to prevent pitting
corrosive, algae, scale, chalky,
and mineral deposits.
Even though, water cooled
condenser require regular
maintenance, it is more efficient
than air cooled condenser, and it
operates at much lower
condensing temperature.
Types of water cooled
condensers:
Tube in tube
Shell and coil
Shell and tube
What are air conditioner
condensers?
Air conditioner condensers are a
heat exchanger device; it has a
similar operation principle to the
evaporator.
The condenser rejects heat from
the air conditioner units to
surrounding air (medium). While
the evaporator absorbed heat
from space that needs to be cool.
In our case, it is from indoor air.
The condenser units take in
high-pressure, high temperature
refrigerant gas from the
compressor and turn it into high-
pressure, high temperature
liquid refrigerant. How does an
ac condenser change refrigerant
gas to liquid refrigerant? Here
how it does that.
Air conditioner condensing unit
work by turning vapor
refrigerant to liquid refrigerant.
There are three important steps
that should happen to the
refrigerant as it passes through
the condensing unit.
First Step: The hot vapor coming
from the compressor must be
de-superheated to the vapor
saturation point. De-
superheated? De-superheated is
removing a sensible heat from
the refrigerant, lower the
refrigerant temperature.
Second Step: In the middle of the
condenser, there should is
mixture of gas/liquid refrigerant.
This is where the refrigerant
vapor should change to 100
percent liquid refrigerant.
Third Step: The refrigerant
temperature should be lowered
below the liquid saturation point,
subcooled.
How does air conditioner
condensers make?
Here is Trane condensing unit
video:
Make sure to press the Play
button in the player controls to
watch it. Enjoy!
How air conditioner condensing
unit work
Refrigeration is the process of
removing heat from one area,
where it is not wanted, to an
area where it not makes a
difference. For the refrigeration
process to work heat has to flow
from one area to another.
Here is a step to how heat will be
transfer from AC evaporator coils
to AC condensing unit.
1. Indoor heat transfer to
refrigerant in evaporator coils
2. Compressor move heat to
condenser units
3. Air conditioner condenser rejects
heat and the process start again
In this discussion, the air
conditioner condensers will
transfer heat to air (not water).
For heat to flow one of the area
has to be at a higher
temperature. This is because
heat always flows from a high
intensity to a low intensity.
The air conditioner condensers
reject heat from the refrigeration
system absorbed at the
evaporator and also heat of
compression from the
compressor. The condenser
contains refrigerant that must
reject its heat to the outside
medium (air that surrounds the
condenser). Therefore, the
refrigerant temperature in the
condenser units must be higher
than the surrounding air.
I will explain how air conditioner
condensing unit work from PH
charts.
The condenser units receive the
hot vapor refrigerant after it
leaves the compressor through
the short refrigeration line
between the compressor and the
condenser unit. This refrigerant
line has known as the hot gas
line or discharge line.
Point 2 on the pH diagram
showed the hot vapor from the
compressor is forced into the
top of the condenser coils. The
vapor refrigerant is being
pushed at high speed and high
temperature to the condenser
units.
The vapor does not
corresponding to the saturation
pressure/temperature
relationship because the vapor
contains superheat added by the
evaporator and the heat of
compression process. This
process is shown between
points 2 to 3.
The vapor entering the
condenser is so hot compared to
the surrounding air that a heat
exchange begins to occur
immediately after the vapor
leaves the discharge area of the
compressor. Generally, the air
will be 90-105°F lower than the
superheated vapor leaving the
compressor.
The first heat exchange removes
sensible heat from the
superheated vapor bringing the
refrigerant vapor to the
saturation point, point 2 to 3 on
the pH chart.
As the refrigerant vapor
continues through the
condenser latent heat is
removed. This process is shown
between points 3 and 4. The
removal of latent heat causes a
change of state to take place.
The vapor will begins to change
to liquid from this point on until
it reaches a point nears the end
of the condenser units where
the entire vapor has changed to
liquid. This is known as the
saturated liquid point, point 4 on
the pH chart.
As the air conditioner refrigerant
flows through the last few rows
of the condenser units additional
sensible heat is removed,
lowering the refrigerant
temperature below its liquid
saturation point. This called
subcooling and represented by
the line from point 4 to 5 on the
pH chart.
There must be enough air
flowing across the AC condenser,
for vapor refrigerant to change
to liquid. The air flowing across
the condenser unit has to be
correct. This airflow has to be at
low enough temperature, so it
could absorb heat from the
condenser unit.
The entire vapor refrigerant has
to turn liquid before it leaves the
condenser units.
Remember, the air conditioner
condensers:
1. Removing sensible heat (de-
superheated).
2. Removing latent heat or
condense.
3. Removing more sensible heat
(subcooled).
This is how air conditioner
condensers work in HVAC units.