How a heat pump works

How a heat pump works

During the heating season, a heat pump can be very economical in terms of energy consumption if it is well chosen according to your needs. Heat pump air conditioning units heat your home using heat from the air and heat from the refrigerant. The majority of the heating power of your heat pump is produced thanks to the compressor which circulates the refrigerant in the refrigeration circuit. The refrigerant is a liquid which has several characteristics, in particular that of being able to change its state (vapor or liquid).

When the compressor is on (heat pump cycle), it compresses the refrigerant to approximately (180°F) which returns the refrigerant to a (hot vapor) state. The refrigerant is then piped to your indoor coil (evaporator).

At this stage, the temperature of the refrigerant gas in your indoor coil is around (85°F to 100°F) because it has been cooled during its journey inside your home. Your evaporator then acts as a heat exchanger, i.e. the indoor fan extracts heat from the refrigerant in your home to heat the surrounding air.

This phenomenon is possible serious at the (reversible valve or reversing valve). This is the main component of the wall-mounted heat pump. It allows the refrigeration system to reverse the cooling cycle that is normally inside your home

How air conditioning works

There are several types of air conditioning units, however, they all work the same way. All air conditioning systems have a compressor, this is used to compress the refrigerant to change its form into a “vapour” state, this is called “hot gas”.

Next, the refrigerant vapor is cooled by a device called the “condenser”. The condenser is used to extract the heat present in the gas and then transform it into liquid (all refrigerants have different boiling point temperatures).

Once turned into a liquid, the refrigerant is routed through an “expander” (an expander is an electronic or mechanical valve that has the function of shocking the gas, this is called “flash gas” – imagine a bottle of spray net, inside there is liquid and when you press the trigger, the liquid comes out in gas to evaporate. When liquid passes through an orifice as big as a hair, the liquid turns into gas). This is called evaporation. The property of the refrigerant is so, when the gas is under the pressure of the expansion valve, the gas evaporates and creates cold in the air conditioning coil which is then extracted by the fan which will cool the space you want to cool. Finally, the refrigerant starts its cycle again thanks to the suction of the compressor (please note that if the system has no leaks, the refrigerant is good for life). The important thing for an air conditioning or refrigeration system is to have no leaks and to have a good level of refrigerant, otherwise the compressor will heat up and you will have compressor overheating problems.

Nowadays, residential air conditioning units are much more protected than before, they are equipped with thermal sensors and electronic probes to detect temperature problems related to the compressor and the refrigerant. However, it is very important to have air conditioning units installed and checked by certified professionals.

What is a heat pump?

An air-to-air heat pump is a device that can provide both heat and air conditioning using outside air as an energy source. Unlike traditional heating systems that burn fossil fuels to produce heat, an air-to-air heat pump uses a heat transfer process to extract heat from the outside air and transfer it inside your home.

 

How does the refrigeration circuit of a heat pump work?

An air-to-air heat pump operates using an inverted refrigeration cycle. This cycle is made up of four steps:

1. Compression: the compressor compresses the refrigerant to increase its temperature.
2. Condensation: Hot refrigerant circulates through a heat exchanger where it releases heat to the outside air.
3. Expansion: the refrigerant expands by passing through an expansion valve, allowing it to cool.
4. Evaporation: Cold refrigerant circulates through another heat exchanger inside your home, where it absorbs heat from the indoor air.

This heat transfer process is repeated in a loop to maintain a constant temperature inside your home.

 

Advantages of a heat pump

There are several advantages to using an air-to-air heat pump:

1. Energy efficiency: an air-to-air heat pump can provide up to three times more heat than it consumes electrical energy, making it a very energy efficient option.
2. Flexibility: An air-to-air heat pump can provide both heating and cooling, meaning you can use one unit year-round to maintain a comfortable temperature in your home.
3. Durability: air-to-air heat pumps are designed to last a long time and require little maintenance.
4. Low CO2 emissions: air-to-air heat pumps use outside air as a source of energy, which means that they do not produce CO2 when they operate.

 

The limits of heat pumps

While there are many advantages to using an air-to-air heat pump, there are also some limitations to consider:

1. Temperature extremes: Some heat pumps can struggle to operate effectively in very cold or very hot weather. This depends in particular on their energy efficiency performance. A high-performance heat pump can produce heat down to temperatures of -30C while some heat pumps will have difficulty producing heat at -10C
2. Noise: Heat pumps can be quite noisy when running, which can be bothersome if you have close neighbors or a bedroom.