Natural ventilation is the most practical and low-cost way to ventilate rooms. But since it cannot always be realized due to the structural and planning parameters and the local climate, it is necessary to solve the problem of circulating air flows artificially. And the simplest technical means of ensuring forced air exchange will be a ventilation fan, which can be used both in private houses and in city apartments.
Instrument design
The device of home fans of this type is calculated on the possibility of integration into the window structure. As a rule, these are supply air ventilators (valves) that provide microventilation in conditions when natural air circulation is not enough, and the main supply and exhaust system, in principle, cannot be performed in this area.
A typical ventilation fan with a cover is a plastic pipe with a diameter of 100 to 250 mm, which also contains filtration grates, membrane elements and anemostats for regulating flows (diffusers). Mostly devices with a rigid structure are used, but there are also flexible models called flexes.
When choosing a fan according to technical parameters, it is important to correlate its characteristics with the opening in the glass. Valves are integrated only into plastic or metal-plastic window structures, and to maintain optimum tightness, it is desirable that the hole in the glass be made in advance by the factory method.
Principle of operation
Fan operation can also be forced or natural. Classic supply models provide free air flow, but in different modes. For example, the circulation rate of a ventilation fan with a constant cross-section does not depend on the needs of the room in fresh air. The air exchange performance will be determined by the pressure drops inside and outside the house - that is, the efficiency of the fan depends on atmospheric conditions.
The only third-party intrusion into the operating mode of the supply air ventilators with a constant cross-section is provided by an additional damper, which can either be slightly covered or completely closed. Fans with bandwidth control work a little differently. They provide for the connection of a power plant (electric motor) and air inflow adjustment mechanisms. Moreover, the adjustment methods are different, which is worth considering separately.
Fan control options
You can adjust valve operation parameters manually or automatically, depending on the model. A manual adjustment method is provided by setting the shutter leaf in a certain position. By varying the size of the gap, you can change the throughput of the device. There is a step or stepless adjustment with several positions.
As for automatic ventilation fans, they all need to be connected to the mains, as well as to sensors for controlling humidity, temperature and pressure. For example, certain pressure parameters outside and inside the room, the level of relative humidity and outdoor temperature determine the inclusion of a particular mode. Physically, the valve is also adjusted using a movable element that closes or opens the passage hole.
Features of hygro-controlled models
A special version of the ventilator that responds specifically to changes in humidity levels. For this control, a tape-shaped polyamide sensor is used. When the humidity coefficient increases, the hygro-controlled forcing fan increases the external influx, and when the minimum level (usually below 30%) is reached, the sash completely closes.
Recuperator Models
Full-fledged supply and exhaust systems in almost all basic configurations are now provided by a recuperator. For compact fans, this is problematic due to the small dimensions of the design, which are hardly combined with the connection of a massive heat transfer unit. And yet, such kits exist. These are forced-air supply and exhaust fans, providing for the restoration (recovery) of heat in the room in three ways:
- Cross The heat exchanger is made of parallel thin plates made of aluminum or plastic. Without mixing from different sides, the spent warm air flows and the newly arriving cold flows from the street pass between them.
- Extended cross. The principle of heat transfer is the same, but in this case, the contact area between the flows through the same plates increases - mainly metal.
- Drum. Also, the method is called rotary recovery, in which the drum mechanism with many channels for the passage of air rotates, distributing thermal energy over the zone of fresh cold air.
Where to install the device?
It is recommended to install fans at a height of at least 2 m from the floor. In a room with heating, the air at this level is warm enough to recover cold flows in the winter. In addition, due to optimum heating, the risk of drafts is eliminated. As for the target premises, these include kitchens, bathrooms, hallways and other places where there is polluted air. Also exhaust ventilating fans are recommended for installation in technical rooms, boiler rooms and laundries.
Installation work
The device is built into the top of the window structure. The most affordable option is to integrate the sash into the profile, but provided that the foreign component does not compromise the strength of the system.
Especially for mounting a fan at the stage of ordering a window, you can stipulate the presence of an impost - a technological zone without glass, which can be used just to connect with other devices. If the design does not initially provide a hole or base for its creation, then you will have to do the mounting niche yourself, also performing a protective visor from the outside. The integration of window and ventilation fans is carried out using construction foam (polyurethane compound) and O-rings of suitable diameter.
It is important to ensure the reliability of the fit of the channel, while not reducing the integrity of the structure. Next, electrical work is performed with gating and cable routing along the wall for direct connection. A simpler option is to connect via a network plug.
Conclusion
Home ventilation systems are largely dependent on the main communications in the form of air ducts and supply and exhaust systems. In turn, compact fans allow you to precisely fill the need for updating the air environment for a particular room. At the same time, they do not require complex installation operations, and during operation they do without major maintenance costs. But this does not mean that the supply ventilation fan is limited in performance. Proper organization of the workflow, especially in the case of automatic models, will provide a very effective means of regulating the microclimate. Plus, the control system in some versions can be combined with groups of local lighting and heating equipment, already comprehensively approaching the issues of autonomous maintenance of a house or apartment.