Air conditioning
for apartments

The channel-type split system includes the unit itself, air ducts, an insulator for ducts (to prevent condensation), a gate valve for adjusting the system, plenum boxes, adapters, designing.

Air distribution grilles or diffusers are designed so that air flows are not directed to the resting or working areas in the apartment. From the point of view of design, they look very nice, all devices are located in the sub-ceiling space and are sewn up with plasterboard. And the grilles and diffusers are located above the windows where the air velocity is lower for moving the air inside the room.

Fig. 4 – Model of channel air conditioning in an apartment based on Daikin equipment.

1. Channel-type indoor units – FDXM 35D and FBA 50F
2. Wall-mounted indoor unit – FTXG 25L
3. Outdoor unit – 5MXS 90E

The channel or duct air conditioning system comes in two types: low-pressure and medium-pressure. Both are used in houses and apartments.
All indoor units of channel type system are located in the technical room (bathroom, dressing room, pantry, corridor). For maintenance of these units, there are access panels that simplify service of filtering elements, electronics, and the inner block itself.

Operating principle of the cooling system

There is a misconception that by installing one air conditioner in one room, you solve the problem with cooling the entire apartment. And it is definitely a false notion and that is why. First of all, any air conditioning system should work zonally.

For instance: we have two rooms, but the air conditioner was placed in only one of them, thinking that it would work for cooling down the second room too. In a situation when a conditioner works only in one room, we do not take into account the temperature sensors within the system. They are programmed for the certain area, so while adjusting the desired temperature inside the room, they either turn off the compressor or minimize the speed (if it is an inverter air conditioner, the compressor switches from 100% to 10% operation mode).

At first glance, everything looks and works as it should. But if you dig deeper, then you should also consider such points:

• • each room should have its own microclimate adjusted to each family member, since every person has a certain comfortable temperature level (for someone +25, for someone +27, for someone +21 feels great);
• • in a family with children, it is important to create an appropriate microclimate for a child. It is usually different from the temperature comfort level of parents;
• • when one of the family members is ill, he needs his own zone of comfort and rest during the day and even at night and consequently, this person also needs to be in his comfortable microclimate.

Taking into account these points, it becomes clear that one air conditioner cools only one zone and cannot satisfy all the individual needs.

Secondly, in the air conditioning project of an apartment or a house, we carry out detailed calculations which include the identification and analysis of all possible heat gains. For example, heat gains from the outside (this is solar radiation, bearings, glazing) and hidden ones, which are indoors (these are heat gains from people in the room, home appliances, heating systems, etc.). Taking into account all these values, we select an air conditioner with the required power. This principle is applied to air conditioning systems of any type.

For instance: why is it impossible to take one channel conditioner and cool 3 rooms all together? We have three rooms that face different sides of the world. Each has its area and its heat gain. All rooms are cooled by one indoor unit. The outdoor unit was picked up at the rate of 2 kW for each room, a total of 6 kW.

The first moment – as mentioned above, we can never adjust the temperature separately in each room.

This is possible only with the installation of a VAV TROX system, aimed at controlling the flow of air. This system opens and closes dampers. Thus, it becomes possible to supply the required amount of air to cool down this particular room. Each room has its own sensor. For example, the temperature is set at + 20 degrees. When the temperature reaches this value, the valve closes. At this time, the engine understands that it is necessary to make the air flow less in order not to create much pressure and no additional noise.

This system is very expensive. Therefore, it is very important for apartment owners to properly implement air conditioning, focusing on heat gains in each room. This will save customers from installing a VAV TROX system and spending more money than needed. As a rule, it is only used in large office centers.

The second mistake is not to take into account the differences between the zones of children’s and adults’ rooms.

The third point – with this implementation, there will be a high level of noise from the unit, also high air flow and, consequently, bigger diameter of the ducts, and therefore more space for lowering the ceiling.
All these moments lead to the inconvenience of a system design in terms of aerodynamics, noise characteristics, distribution of cold and energy consumption. When we have one channel indoor unit cooling its zone, there is no need to turn on a large unit. So, energy consumption will be three times less.