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.