When it comes to calculating an air conditioner by area, the type of room that will be served plays a major role in selecting the right model for climate technology. The easiest way is to choose a cooling device for an apartment, and the hardest one is for a server or industrial room, requiring constant temperature parameters and a certain humidity level.
Of course, specialists know better how to select an air conditioner by area, but to assess the quality of the services provided by the masters, the customer should be aware of some features of the correct calculation.
The choice of air conditioning in an apartment or small office
As a rule, for residential premises, buyers prefer split- or multi-split systems with an indoor unit of various designs. To select the air conditioner of the required power (or rather cooling capacity or power in the cold), it is not enough to know only the size of the room, you also need to calculate the volume. What else needs to be considered when choosing an air conditioner for an apartment by area, and how to make calculations?
There are special formulas in which, in addition to the area, take into account the heat (or heat influx) from:
- people constantly there - 0.1-0.2 kW;
- constantly working household appliances - 0.2-0.4 kW for each device;
- TV and computer - 0.2 and 0.3 kW, respectively;
- windows and doorways (it is important to take into account the side of the world where the window goes);
- the roof.
Both the roof and the windows with doors have an average heat gain of 30-40 W / m³. The ceiling height can also be a plus, since at its values more than 3 meters the power will have to be increased.
The obtained value of the required cold (Q) will be equal to the sum:
- heat influx from windows, doors, ceiling, walls and floor, multiplied by the area and height of the room (Q₁);
- heat influx from people (Q₂) and all household appliances (Q₃).
To choose an air conditioner for an apartment by area, you have to use this formula:
Q = Q1 + Q2 + Q3
But there are even simpler options that eliminate the need to multiply, add, and count.
Far from news - these are online calculators for calculating air conditioning in rooms up to 70 m². Simply enter all the data and the program will produce a finished result.
In practice, experts very often add to the nominal cooling capacity indicated in the manual another 30% of it as a reserve for the items listed above, or for every 10 m² they take 1 kW + 20% from the top of the result.
In general, a power reserve is always necessary where the windows face the sunny side of the world or the roof is very hot.
The choice of air conditioning in the server room
To begin with, it is worth clarifying what a server room is, and what requirements for climate equipment exist for it.
The server room usually accommodates large-sized equipment for special purposes (telecommunications, computing facilities, etc.), which is responsible for the company’s regimen and its connection with the outside world. The sizes of such rooms can vary greatly - the area can be as much as 3 m², or several tens or even hundreds of meters. How to choose an air conditioner according to the area of the room in the server room so that the expensive equipment of the company and the climate control unit itself do not fail prematurely?
Climate technology in such areas is very demanding.First of all, the calculation of the conditioning area implies year-round compliance with climate standards:
- temperature not less than 18 ° C and not more than 24 ° C (deviations may be about 1 ° C);
- humidity within 40-60% (deviations of about 1%);
- dustiness of air (about 0.75 mg / m³), which eliminates the installation of the device with a powerful filtration system;
- optimal air velocity (0.2 m / s).
Of course, the main role is played by the air conditioning area, when it comes to calculating the required cooling capacity, but even this value for the server is obtained in a different way.
Basic calculations
As a basis, take the sum of the areas of the floor, ceiling and walls. They do this according to the following formulas:
- the length of the floor or ceiling (L) is multiplied by their width (B);
- the height of the walls (H) multiplied by their width (B);
- further summarize the data.
Thus, the total heat release area is obtained.
Now, the calculation of the air conditioner by the area for the server room is carried out according to the following points:
- determination of the total heat emission of the equipment itself + additional equipment;
- determination of heat influx from:
- window openings - 0.02 kW per meter of glazing with the shadow side and 0.2 kW with the sun;
- floor, walls, ceiling - do according to the formula specified in the description of the choice of air conditioning in the apartment by the area of the room;
- lighting devices - multiply among themselves the number of lamps, their power and the average efficiency of the use of electricity for lighting;
- heating appliances - about 0.1 kW / m²;
- supply and exhaust ventilation - measure the air velocity near each supply grille and multiply by the coefficient of living section;
- people - an average of 0.175 kW per person.
To calculate the amount of heat generated by servers and other equipment, it is necessary to use the technical documentation for the equipment and add up all the values or measure the current strength on the power cable at the time of maximum electrical load, and then multiply the obtained values by the voltage in the network.
For example, with a current of 40 A and a voltage of 400 V, the total thermal power of the equipment will be 16 kW.
The method with measuring current is more accurate, since the documents indicate the nominal values calculated by average indicators, which may differ by several percent from the actual workers.
When all the data is ready, it remains only to add up the results and, we can say, the selection of the air conditioner according to the room area for the server room is completed.
Some experts simplify the whole procedure and do this:
- require IT administrators to have a competent technical task with access to documentation on server equipment;
- to the total heat dissipation capacity of servers add another 30% of the received amount (heat inflows from everything else are laid in them).
But this method still does not guarantee 100% accuracy, and the craftsmen using it act at their own peril and risk.
Air Conditioning Reservation
As for the backup equipment, when calculating the air conditioner relative to the server area, the rule of alternate operation of the devices applies here. The basis is usually laid either 50% of the reserve or all 100%.
When backing up only half, one device out of three is left as a spare. In the event of a full reservation, the number of spare air conditioners doubles. If one or several devices fail, then before the arrival of the specialists, the backup device takes over the operation. Sometimes, initially, the system assumes that all units work in turn.
Other work organization devices
If the area of the room is large, and there are several air conditioners, then it is necessary to take into account and install the coordination of the operation of devices - a rotation device.It ensures the uninterrupted development of the resource of climatic units by means of their alternate inclusion in work with a given period of time. When the set temperature increases, a spare air conditioner is connected to the operation, and in case of exceeding the allowed marks, a signal is sent to the dispatcher's control panel. Rotation systems are used both in conjunction with scheduling systems, and independently.
For the coordinated operation of all climate equipment, it will be necessary to install an automatic control system that is responsible for controlling:
- climate data;
- work of internal elements of devices;
- refrigerant circulation;
- signals about dangerous situations and accidents;
- operating time of each module and its switching.
Remote control is excellent through computer monitoring.
Which conditioner to buy
Often it is practiced to install semi-industrial splits (high-quality column, channel, wall and console) in the server room, but this is justified only in cases with small rooms. There is only one advantage - a lower price than professional precision air conditioners.
But most of them are not able to work year-round and 24/7. You will definitely need a winter kit so that these units cool the room in winter at temperatures below -5 ° C on the street, otherwise, in addition to obtaining low efficiency and compressor failure in the future, a server hardware failure may occur. Often it is necessary to install an air humidifier, and this causes inconvenience in maintenance, since it requires constant filling with water.
The best solution for the server will be precision air conditioning, as:
- Its design is designed to constantly maintain the desired temperature and humidity;
- it has a fan many times more powerful than a fan of domestic and semi-industrial models of air conditioners;
- it is equipped with a multi-stage filtration system, which solves the problem of dusting of electrical equipment;
- it gives high efficiency at work, since useful activity is not spent on condensation;
- It is fully combined with the building climate control system.
Among precision systems, the bulk of the devices has an expanded power range in the cold - from 5 to 100 kW. Outwardly, such air conditioners are similar to cabinets, and their installation differs little from a column or cabinet type installation. Depending on the needs of the room, you can choose a precision device that works on the principle of freon, water or mixed cooling.
If the choice of an air conditioner by the area of a room is made for a server room of large sizes, then, due to the listed advantages, a precision installation is preferable. Its only minus is the high cost of construction and installation.
MITSUBISHI ELECTRIC precision air conditioners exhibit the most positive performance characteristics. LIEBERT HIROSS, DAIKIN and UNIFLAIR.
Choosing an air conditioner in a production room
In fact, the process of how an air conditioner is calculated according to the area of a room for a production or warehouse does not differ from the selection process for a server room. Just instead of server hardware, there are various production facilities (depending on what is produced or stored). Their total heat gain is calculated in the previous way.
In this area, precision air conditioners have proven themselves best. Mounting options for VRV and VRF systems, chiller and fan coil, central air conditioning are also possible.
When purchasing a precision installation, air conditioning made to order is preferred, since this is the option that can take into account all the nuances of a particular building. To do this, you need to correctly calculate all the parameters and choose the most optimal characteristics of the equipment
