Heat pumps are a common heating
and cooling system that people use in their home. The main reasons
why they are popular so much is the fact that Heat
Pumps costs less in terms of AC maintenance & repair expenses.
This is because heat pumps operate on the heat transfer principle and do not
run by the energy generated by burning fuel.
Now, before I go to Air-Source heat pumps in details, you
should know how heat transfer works and how heat transfer reduces HVAC cost.
What is heat transfer & why it is efficient in saving from HVAC cost?
While many heating and air conditioning systems
use the traditional fuel burning to accomplish its target, most of modern day air conditioning units
use the heat transfer principle to make a room cold or keep it
heated.
Heat transfer is simply the “transfer of heat”. So, any HVAC
system that is using heat transfer will simply transfer the heat from one place
to another. And since, the heat is not being generated but just being
transferred from one place to another. And the place where the heat is sourced
is called the source. Since they are not generating the heat and just
transferring from one place to another, the fuel or electricity cost is
slightly trimmed down.
What is an Air-Source heat pump?
Heat pumps as I said transfers heat. The place or object
where it transfers the heat is called the source. Depending on the source,
these heat pumps have different names.
The three primary sources for heat pumps are air, ground and
water, even though some argue water and ground to be the same.
Depending on the source, these heat pumps are named
Air-Source heat pump, Ground-source heat pump and Water-Source heat pump. Sometimes
the Ground-Source heat pump and Water-Source heat pumps are collectively referred
to as Geothermal heat pumps.
As you have noticed, we are talking about Air-Source heat
pumps today which sources the heat from, you guessed it, the air. I wouldn’t be
crossing a line if I say heat pumps are basically the most common HVAC system
used in North America.
How heat transfer of Air-Source Heat Pumps work for heating and cooling
your home?
A general Air-Source heat pump has three cycles.
I.
The heating cycle,
II.
The cooling cycle and
III.
The defrost cycle
1.
The heating cycle
During this heating cycle, heat is taken from outdoor air
and then exerted indoors.
-
First of all, the liquid refrigerant goes
through an expansion device where it is transformed into low-pressure
vapor/liquid mixture.
-
It goes to the evaporator coil where it absorbs
heat from the outside air and then the mixture boils.
-
The vapor now passes to the accumulator before
entering the compressor.
-
The vapor is compressed to reduce its volume
which causes it to heat up.
-
Reversing valves send this hot gas to the indoor
coil, acting as a condenser.
-
The hot gas then transfers the heat into the
room and the gas then transfers into its original state as liquid refrigerants.
-
This cycle is repeated until the expected
temperature is not achieved.
2.
The cooling cycle
The cooling cycle is just the reverse cycle of the heating
one and used in summer to cool down the house. The basic concept here is to
take the heat from indoors and exert is outside.
-
First of all, the liquid refrigerant goes
through an expansion device where it is transformed into a vapor/liquid
mixture, much like the heating cycle.
-
It goes to the evaporator coil where it absorbs
heat from the inside air and then the mixture boils, turning into low-temperature
vapor.
-
The vapor now passes to the reverse valve and accumulator
before entering the compressor.
-
The vapor is compressed to reduce its volume
which causes it to heat up.
-
Reversing valves send this hot gas to the outdoor
coil, acting as a condenser.
-
The hot gas then transfers the heat into the outer
environment and the gas then transfers into its original state as liquid
refrigerants. The liquid then returns to the expansion device.
-
This cycle is repeated until the expected
temperature is not achieved.
During this cooling cycle, these air-source heat pumps dehumidify
your indoor room air, the opposite of what the heating cycle. The moisture of
the air passes over the indoor coil. This forces it to condense on the indoor
coil’s surface. Then it is collected in a pan which is placed at the bottom of
the coil. This liquid is then connected to the house drain for exertion.
3.
The Defrost cycle
When the outdoor temperature is below or close to freezing
during the heating cycle, the moisture from the air passes over the outer
coils. There, the moisture is condensed and froze. This moisture frost buildup affects
the efficiency of the HVAC system as
the transfer of heat is halted.
Eventually, to restore the efficiency of the system, the
frost should be removed. Thankfully heat pumps have the defrost cycle in motion
so that efficiency is never compromised.
-
First of all, the reverse valves switch the HVAC
unit to its cooling mode.
-
When this happens, the hot gas is then
transferred to the outer coil. This heat in the outer coil then melts the
frost.
-
Around the same time, your outdoor fan is
usually shut off. This happens so that the heat is now wasted by blowing air
out.
-
When this is happening, the heat pumps are used
to cool the air in the ductwork, even though usually the heating system will
heat up the air to be distributed throughout the home.
Bottom Line
Now that you know everything about the Air-Source Heat
pumps, it is time for you to get one for you.
You can check out great deals on heat
pumps that we have here.
Visit our store here.