What is an enthalpy recuperator and how does it work?

An enthalpy recuperator allows to improve the efficiency within the home’s air conditioning system. However, it is a modern piece of equipment, so it is worth taking a hard look at what it is and how it works, in order to decide if it is worth installing one at home.

The quality of the air inside the house depends on the ventilation system. Traditionally, it is recommended to open the windows for a few minutes a day to extract the stale air and let in clean air. In this way, it is possible to avoid allergies and more serious respiratory problems. In addition, the renewal of the air allows to reduce the levels of carbon dioxide (CO2) accumulated in the rooms, since in high concentrations this compound can be harmful to humans.

However, the necessary conditions to achieve good natural ventilation do not always exist. For example, during the winter we avoid opening the windows at all costs so as not to lose the temperature inside the house. Also, in very tall buildings it is not safe to open the windows at any time of the year, therefore a ventilation system is necessary. 

Benefits of heat recuperators

Achieving efficient ventilation in interior spaces such as buildings, commercial premises and houses is now possible in any season thanks to heat recovery units. This equipment is not only capable of renewing the air, but also uses a heat exchange system to pre-cool or pre-heat the outside air, so that when it enters the room again, the air conditioning system does not have to spend too much energy to maintain the temperature. suitable indoor temperature.

It is good to know that this system also has a filter to prevent the entry of particles and small insects. In this sense, ventilation with heat recovery is considered a more environmentally friendly solution, but at the same time it allows maintaining optimal health and comfort conditions . But that’s not all, it also provides greater savings on the electricity bill. 

The type of energy recovered

Heat recuperators are classified according to the type of energy recovered, for this it is important to understand that there is so-called sensible heat, which allows the temperature to change but not the state (solid, liquid, gas). On the other hand, there is the latent heat, which can cause a change of state, but maintaining the same temperature. In the case of enthalpy recuperators, they are capable of recovering both sensible and latent energy. 

Enthalpy heat recovery operation

In a technical sense, the operation of this system is quite simple, so you do not need to be an expert in enthalpy diagrams. As we have pointed out, this equipment is responsible for recovering part of the energy from the air that has been heated inside the house, to take advantage of its temperature and humidity through an air exchanger. This element is of great importance, since it is in charge of putting the air that comes out of the interior in contact with the one that enters from the outside, but without the need for the stale air to mix with the new one. 

Main types of heat exchangers

The type of exchanger that the equipment has is essential to understand the efficiency of the heat recovery unit. One of the most used by manufacturers is the cross-flow method, where the air inlet and outlet flows cross perpendicularly inside the device, offering an efficiency of approximately 50 to 85%.

For its part, in the parallel flow exchanger, the inlet air flow circulates parallel and countercurrent to the outlet air, thus increasing the exchange surface and time, thus offering a greater capacity for temperature recovery., thus achieving an efficiency of 95%. 

There is also the rotary type exchanger, which, as its name indicates, produces a rotary movement to generate heat exchange between the inlet and outlet flows. In this case, metallic cells are heated by the hot flow. Thanks to the rotation of the device, the cells transmit heat to the cold incoming air, achieving an efficiency of approximately 85%. 

Is the use of heat recuperators mandatory in Spain?

The installation of enthalpy recuperators in houses is optional in Spain, at least until now. However, the Regulation of Thermal Installations in Buildings (RITE) indicates that if a building expels an air flow greater than 0.5 m3/s to the outside by mechanical means, then it must recover the energy of the expelled air. This means that in the near future most buildings will have to include heat recovery units . 

Maintenance and care of enthalpy recuperators

If the air conditioning systems with heat pumps need periodic maintenance, we can have an idea of ​​the importance of thoroughly cleaning the enthalpy recuperators, since otherwise their efficiency is compromised, especially in terms of the purification capacity of the air, putting the health of the inhabitants of the home at risk. This can cause an additional cost in the technical service, but it is also possible to carry out the maintenance at home, following the technical guides provided by the manufacturers.

Another important feature of this equipment is that it produces a certain amount of residual water due to condensation, so it is necessary to ensure that the water is correctly channeled to the outside to avoid excess humidity and damage to the recuperator itself. However, it is not a very complex installation.

In summary, we can say that the enthalpy recuperator provides different benefits in the air conditioning of homes and commercial premises, helping at the same time to preserve the environment, but it is also a system that requires certain care to guarantee optimal operation and a long life. helpful, so it’s important to weigh its pros and cons before making a decision.