How to choose an air recuperator for your home and apartment
System type
An important criterion for choosing a recuperator is the type of system - centralized or decentralized. The first is the most expensive, difficult to install and maintain. Such devices work well at the stage of design and construction from scratch of residential and commercial buildings. Centralized recuperators are being implemented into a single ventilation system with an extensive network of ventilation ducts. They are able to provide fresh air to multi-storey buildings and industrial premises.
For domestic use in a private house or apartment, the best option is a decentralized system that will provide the necessary air exchange in a separate room or studio apartment. It is distinguished by independent installation on any wall that faces the street, and for operation it only requires connection to a standard 220V electrical wiring. Such recuperators are small in size, stylish in design, and easy to operate.
Installation method
There are several main installation options - floor, wall, suspended, universal. The installation method largely depends on the layout and technical conditions of the room, as well as the type of system. Centralized recuperators often practice suspended installation due to their integration into the main ventilation located under the ceiling. With this approach, the equipment can be completely hidden, preserving the aesthetics of the interior and further reducing the noise level. Manufacturers also offer floor and wall options. It is worth understanding that installation on the floor may create certain inconveniences. Firstly, the recuperator will take up some of the free space. Secondly, it will create background noise. Therefore, floor-standing models are often installed in separate technical rooms - boiler rooms, boiler rooms, storage rooms.
For decentralized ventilators, the standard installation is in the wall, which is most practical for domestic premises (apartment, house, summer kitchen, garage). This method does not require redevelopment, re-issuance of documentation, complex technical work, and installation can be carried out in any convenient place on the wall at the user’s request. It is enough to drill a hole for the air duct and connect a 220V socket.
Air exchange performance
Correct selection of the performance of supply and exhaust systems is extremely important for a healthy microclimate in the apartment. Balanced air exchange provides the necessary level of oxygen, humidity, temperature, and avoids hypoxia and the spread of mold. When calculating, you can be guided by the number of people in the room or the area. According to the standards, it is necessary to adhere to the following indicators of supply air flow for residential premises (living room, bedroom, children's room):
| Microclimate conditions | Supply air flow rate for residential premises according to DBN, m³/h | ||
|---|---|---|---|
| Based on 1 person | Based on 1 m² of room | ||
| Increased optimal | 36 | 5 | |
| Optimal | 25 | 3.6 | |
| Acceptable | 15 | 2.2 | |
Acceptable : conditions that provide the minimum required supply of fresh air. With such air exchange, the human body has to spend more energy for life, active actions are difficult and can lead to rapid fatigue. It is not recommended to stay in such a room for a long time.
Optimal : in such conditions, the normal functioning of the body is ensured with natural heat exchange and sufficient oxygen saturation. The person demonstrates increased performance and physical activity.
Increased optimal : conditions necessary for the active life of children, the elderly, as well as during the course of various diseases that affect respiratory processes and the absorption of oxygen in the blood.
Thus, the optimal volume of fresh air that should enter the room to meet the needs of one person is 25 - 36 m³/h. If we calculate based on the area (without taking into account consumers), then for each m² of room, with a standard height of 2.5 m, 3.6 m³/h of air is required. When choosing a recuperator, you must be guided by those parameters that will better reflect the actual air consumption in the room. For example, for a large living room it is convenient to make calculations based on the area, multiplying each m² by the norm of 3.6 m³/h. For a small kitchen, where 3 to 4 people can gather at the same time, it is necessary to pay attention to the number of consumers and provide a norm of about 30 m³/h for each. Guided by the standards and parameters of the room, you can easily determine the performance of the recuperator suitable for your living conditions.
Let's look at specific examples. For a room of 20 m², where 4 people live, it is more rational to take into account the consumers. According to the room size, the heat exchanger capacity should be 72 m³/h (20 x 3.6), but 4 users will consume at least 120 m³/h of air (4 x 30).
For a living room with an area of 14 m² with two children living in it, it would be correct to calculate the dimensions based on the standards of increased comfort. In this case, the heat exchanger capacity should be approximately 90 m³/h (14 x 5), despite the air consumption of two users at 70 m³/h.
Heat exchanger type and material
The presence of a heat exchanger is what distinguishes recuperators from conventional supply and exhaust systems. It is this that ensures the accumulation of thermal energy for its transfer to the supply cold air. There are 2 main types of heat exchanger - plate and rotary. The latter is complex, expensive and noisy, so it is used only in centralized systems. It is based on a separator drum in which discs rotate and heat exchange occurs.
Plate recuperators are distinguished by their simplicity of design, maintenance, and low noise level. They are well suited for apartments and private houses. But their efficiency and cost depend on the manufacturing materials that participate in heat exchange. The main parameters that are important to consider are thermal conductivity, safety and wear resistance. Let's figure out what properties this or that material has. For ease of presentation, the data is combined into a table.
| Material | Properties of manufacturing materials | |||
|---|---|---|---|---|
| Thermal conductivity | Safety | Wear resistance | Price | |
| Cellulose | Average | Low | Low | Low |
| Plastic | Low | Average | Average | Low |
| Aluminum | High | Low | High | Average |
| Ceramics | Average | High | High | High |
| Copper | High | High | High | High |
You can easily determine that cellulose and plastic are ineffective and therefore are quite rare, despite their budget cost. Pulp is prone to odor accumulation, and its purification process does not involve rinsing or other contact with water. Moreover, under the influence of moist air, bacteria and mold can spread inside.
The plastic structure does not save heat well, but is easy to clean from dirt. According to research from the New England Journal of Medicine, many bacteria and viruses (including COVID-19) can survive on plastic for 72 hours, without doing much to prevent the pandemic.
An aluminum heat exchanger is a rather controversial solution, where everything depends on the quality of manufacture and frequency of use of the recuperator. The advantages of the material include high thermal conductivity, wear resistance and low cost. It quickly absorbs heat and releases it at the same speed. Such a heat exchanger can be easily cleaned under running water, quickly dried and put back into service, which will last for many years. The disadvantage is the negative impact on the lungs with constant use. It is worth remembering that all products made from it (irons, frying pans, mugs) usually have an additional protective coating. Aluminum dust can cause a disease called Aluminosis. The heat exchanger is suitable for periodic use as a means of additional ventilation.
Despite the popularity of ceramics, it does not occupy a leading place in the design of the recuperator. The material is valued for its wear resistance and safety, but the cost of models with a ceramic heat exchanger is often very high. Moreover, the heat transfer efficiency is at an average level. Ceramic is capable of accumulating heat, but also retains it well without completely releasing it to the supply air. However, the efficiency of such recuperators is much higher than their cellulose and plastic counterparts.
The copper heat exchanger wins in all respects, but requires paying a high price when purchasing equipment. Natural antiseptic properties make it the safest for health. For example, coronavirus strains are destroyed on such a surface within 4 hours. Copper also helps neutralize bacteria, mold, and allergens. The material accumulates and releases heat best of all, providing the highest efficiency (more than 90%), is not subject to corrosion, does not change its physical and chemical properties when temperature conditions change, and can withstand many years of use.
Recuperators with a ceramic or copper heat exchanger are a long-term investment that will be fully justified by good health and a cozy microclimate in your apartment or house. They are optimally suited to serve as the main ventilation system in the room and are capable of operating 24/7 for many years.
Recuperators with an additional heater can be classified into a separate group. Decentralized household models use an electric type of air heating, and their power depends on the performance of the ventilator. The presence of this module can turn the supply and exhaust system into an alternative source of heating in the autumn-spring period and reduce the load on heating devices in the winter. However, like any heating devices, the heater can dry out the air. This problem can be solved with the help of humidifiers. To operate the devices, you will need wiring that can withstand the corresponding loads, and electricity consumption increases many times over.
Centralized recuperators often use water heating. such devices work in tandem with the heating system, significantly increasing its efficiency.
Noise level
Another important point when choosing a recuperator for an apartment is the noise level. Air circulation on a regular basis, and especially at night, should not create discomfort for adults and children. Therefore, the optimal noise threshold is considered to be up to 35 dB at maximum load. In this mode, the recuperator operates only when intensive ventilation is necessary, and the rest of the time a lower impeller speed and, accordingly, noise level are used.
Availability of a filtration system
The fresh air supplied to the room by the recuperator may contain various impurities in the form of dust, bacteria, viruses, and allergens. Therefore, most supply and exhaust systems are equipped with filters, although not all can be called effective. According to international standards, G1 – G4 is considered the simplest class. It traps particles with a size of 0.4 microns and in fact is a pre-filter for coarse cleaning of dust, debris, and animal hair. The second most effective class from the end is assigned to class F5 - F9, which allows you to get rid of most contaminants down to 0.4 microns. These filters prevent bacteria, mold, and pollen from entering the home. Finer cleaning is guaranteed by class H10 - H14, which is known to everyone as HEPA. Such fine filtration systems are highly efficient and are capable of neutralizing 99.995% of particles measuring 0.3 microns. The absolute leader, including in cost, is the U15 – U17 class, but its use is limited to highly specialized areas (medicine, science, industry) and is not relevant for the domestic sphere.
When choosing a ventilator, you need to pay attention to the quality of the filtration system. For most users, class G will be sufficient, but for children, allergy sufferers, the elderly and those with weakened immune systems, more careful control of the H level is recommended. The best option would be F-filters, which will get rid of not only dust, but also most pathogens, creating a healthy atmosphere in room.
Additional features
The efficiency and economy of the recuperator, comfort and ease of control largely depend on additional capabilities. They can be implemented as physical modules or software add-ons.
Display and remote control
Visual control and setting parameters will be more convenient if there is a display. Some models are capable of diagnostics and help users troubleshoot problems using special codes or on-screen indications, for example, when mechanisms are icing.
The remote control allows you to quickly change operating modes within the room. The bottom line is that recuperators are often installed in the wall under the ceiling, so the user will not physically be able to use the control buttons on the device. Maximum comfort is achieved using the Wi-Fi module and software for mobile gadgets. Control and change of operating parameters with this approach can be carried out via the Internet.
Ionization and humidification
The built-in ionizer is able to improve the quality of incoming air, saturates it with negative ions, which help suppress bacteria and settle dust. Such an addition would be appropriate if there are increased requirements for the purity of air masses in an apartment where an allergy sufferer or child lives.
CO₂ sensor
Availability of carbon dioxide sensor allows you to automate control and ensure the safety of people in the premises. It is important to know that high concentrations of CO₂ can cause loss of consciousness. Elevated levels lead to fatigue, weakness, and insufficient brain activity. In the absence of intra-house ventilation or disruption of its functionality, the risk of carbon dioxide accumulation increases significantly. A recuperator with a CO₂ sensor monitors the condition and automatically renews the air in the room to create comfortable and safe conditions.
EC fan and speed control
The ability to adjust the speed is provided in almost all recuperators. The number of speeds depends on the model and its performance. For low-power units with a capacity of up to 100 m³/h, 3 speeds can be considered the standard, which is enough to compensate for air costs in a small room. A larger quantity is used to organize intensive ventilation and recirculation in larger rooms. Such recuperators have increased power and offer 5 – 10 speed options.
The presence of an EC fan significantly expands the functionality and efficiency of recirculation. It uses a brushless motor, which has many advantages over traditional ones. Firstly, it allows you to smoothly regulate the speed and precisely adapt the air inflow/outflow performance depending on the situation. Secondly, it guarantees a minimum noise level. Thirdly, it is more economical and durable.
Despite the apparent simplicity of the design, the recuperator is a rather complex system, so when choosing, you need to pay attention to all the nuances indicated above. Only after preliminary calculations and determination of key parameters can you select a ventilator as accurately as possible, which will provide the required volume, filtration of exhaust and supply air, safety and operating comfort, long-term operation without repairs and overpayments for energy.
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