The modern world strives to preserve the environment and improve the quality of life, and in this context, the role of high-quality indoor ventilation is growing.

Today, the market for heat recovery ventilation systems offers many different solutions. At the center of these technologies is a heat exchanger, which provides heat transfer from exhaust air to fresh air entering the room. The choice of heat exchanger type is a key factor that determines the efficiency of the recuperator, its ability to store heat, as well as the level of comfort and savings for the user. What is the difference between them and how to choose the best one?

One of the main differences between recuperators on the market is the type of heat exchanger material. They are made of plastic, copper, ceramic, aluminum, and cellulose. The materials are different, but they are all aimed at achieving high energy savings. Let’s find out which one should be preferred.

Ceramic – this material is mostly used in the manufacture of compact reversible ventilation systems. Such systems operate in two cycles – supply and exhaust, 30 seconds each. The ceramic heat exchanger is heated by receiving heat from the exhaust air and transferring it to the supply air. The material has the ability to retain heat for a long time, and its thermal conductivity is up to 75%. However, the ability of ceramics to retain heat for a long period of time is a disadvantage when recovering cool air during the heating period, because the material takes a long time to cool and requires additional electricity to cool. Another disadvantage is the specifics of the ventilation system itself. For high-quality air recovery, it is necessary to install ventilation systems in pairs in the same room (one should work for supply and the other for exhaust) to maintain the balance of air flows and prevent backdrafts.

Cellulose – heat exchangers made of this material are lightweight, but this material has the properties of absorbing unpleasant odors and is not durable. It is not recommended to install a recuperator made of this material in places where there are strong odors. Another disadvantage of the cellulose heat exchanger is its sensitivity to moisture, which can lead to deformation in case of excessive air humidity. Recuperators equipped with cellulose heat exchangers lose efficiency at low temperatures, as this material freezes at temperatures as low as -5°C.

Plastic – this material is not widespread and is rarely used. The thermal conductivity of plastic reaches up to 85%. The disadvantage of the material is the lack of antiseptic properties. Accordingly, viruses that get on the plastic heat exchanger during the ventilation process live up to 72 hours, during which time the recuperator with this heat exchanger will perform several thousand supply and exhaust cycles, which can negatively affect air quality, and as a result, the human body. Plastic heat exchangers do not transfer moisture between air streams, which can cause the indoor air to dry out during the heating season, and resistance to mechanical damage is much lower, which can reduce the service life of the heat exchanger. In addition, some types of plastic can degrade under the influence of UV radiation, so they require additional protection in open spaces.

Aluminum is a material that is lightweight and has good thermal conductivity. However, under certain conditions, this material can be dangerous to the human body. During the ventilation process, aluminum particles get into the air, which subsequently enters the human body through breathing. Excessive amounts of aluminum in the body can lead to respiratory diseases, reduced immunity, etc. Aluminum heat exchangers have significantly lower strength compared to steel or copper, which makes them less resistant to impacts and requires additional coatings to prevent corrosion in contact with water and other liquids.

Copper is the material chosen by PRANA engineers for the entire model line of the brand, which has won the favor of the audience and gained great popularity in the ventilation equipment market. Due to the high thermal conductivity of copper and its antiseptic properties, the supply air is completely safe, as copper prevents the growth of viruses, bacteria and fungal contaminants on its surface. Among all types of heat exchangers, copper has the highest thermal conductivity – up to 98%. Additional advantages of a copper heat exchanger are the ability to keep the room both warm and cool during air conditioning, high strength and durability, and resistance to mechanical damage.