Diagram of air flow through a ducted air conditioner. How to choose a duct air conditioner? Design and principle of operation of a duct air conditioner

WITH cooling capacity power consumption should not be mixed as this is completely different parameters. The cooling power is several times higher than the power consumed by the air conditioner. For example, an air conditioner consuming 700 W has a cooling power of 2 kW, and this should not be surprising, since the air conditioner works just like a refrigerator, the coolant (freon) takes heat from the air in the room and transfers it to the street through a heat exchanger (external unit of the air conditioner) . The power ratio is called air conditioner energy efficiency(EER). For household air conditioners this parameter will have values ​​in the range 2.5 – 4.

Below is the distribution table capacities air conditioners. Using it, you can select the types of air conditioners that are most optimal in certain conditions. For example, in small rooms or offices where low-power air conditioners are required, it is more rational to install mobile, window or wall-mounted models. Air conditioners other models have higher power and, accordingly, higher prices, so it is better to purchase them for cooling large premises (sales halls, warehouses, etc.)

Power units

With the SI system it has the following relationship:

• 1W=3.4 BTU/h or
• 1000 BTU/h=293 W

How to calculate the power of an air conditioner

Power (more precisely, cooling power) is the main characteristic of any air conditioner. Approximate calculation of cooling power Q(in kilowatts) is produced according to generally accepted methods:

Q1 = S * h * q / 1000, Where

S room area (sq. m);

h room height (m);

q coefficient equal to 30 - 40 W/kb. m:

q = 30 for a shaded room;

q = 35 at average illumination;

q = 40 for rooms that receive a lot of sunlight.

If direct lines enter the room sun rays, then the windows should have light curtains or blinds.

Q2 the sum of heat inflows from people.

Heat gain from an adult:

0.1 kW in calm state;

0.13 kW with light movement;

0.2 kW during physical activity;

Q3 sum of heat inflows from household appliances.

Heat gains from household appliances:

0.3 kW from a computer;

0.2 kW from TV;

The power of the selected air conditioner should be in the range from -5% to +15% design power Q. Note that calculating the air conditioner using this method is not very accurate and is only applicable for small rooms V capital buildings: apartments, separate rooms of cottages, office premises with an area of ​​up to 50 - 70 sq. m. For administrative, trade and industrial facilities other methods are used that take into account more parameters.

An example of calculating the power of an air conditioner

Let's calculate the power of the air conditioner for a living room with an area of ​​26 square meters. m with a ceiling height of 2.75 m in which one person lives, and also has a computer, TV and a small refrigerator with a maximum power consumption of 165 W. The room is located on sunny side. The computer and TV do not work at the same time, since they are used by one person.

• First, we determine the heat inflows from the window, walls, floor and ceiling. Coefficient q let's choose equal 40 , since the room is located on the sunny side:

  Q1 = S * h * q / 1000 = 26 sq. m * 2.75 m * 40 / 1000 = 2.86 kW.

• Heat inflows from one person at rest will be 0.1 kW.

  Q2 = 0.1 kW

• Next, let’s find the heat inflows from household appliances. Since the computer and TV do not work at the same time, only one of these devices needs to be taken into account in the calculations, namely the one that generates more heat. This is a computer whose heat output is 0.3 kW. The refrigerator emits about 30% of its maximum power consumption as heat, i.e. 0.165 kW * 30% / 100% ≈ 0.05 kW.

  Q3 = 0.3 kW + 0.05 kW = 0.35 kW

• Now we can determine the estimated power of the air conditioner:

  Q = Q1 + Q2 + Q3 = 2.86 kW + 0.1 kW + 0.35 kW = 3.31 kW

• Recommended power range Q range(from -5% to +15% design power Q):

  3.14 kW< Q range < 3,80 кВт

All we have to do is choose a model of suitable power. Most manufacturers produce split systems with capacities close to the standard range: 2,0 kW; 2,6 kW; 3,5 kW; 5,3 kW; 7,0 kW. From this series we choose a model with a capacity 3,5 kW.

It is interesting that models from this series are often called “7” (seven), “9” (nine), “12”, “18” “24”, and even the marking of air conditioners is carried out using these numbers, which reflect the power of the air conditioner in a way other than the usual kilowatts, and in BTU/hour. This is due to the fact that the first air conditioners appeared in the USA, where they are still used British system units (inches, pounds). For the convenience of buyers, the power of the air conditioner was expressed in round numbers: 7000 BTU/h, 9000 BTU/h, etc. The same numbers were used to label the air conditioner so that its power could be easily determined by its name. However, some manufacturers, such as Daikin, tie model names to power expressed in watts, so Daikin air conditioner FTY35 has a power of 3.5 kW.

Additional parameters to consider when choosing an air conditioner

Decide this problem not difficult. You can ventilate the room with the air conditioner on at any time, but you should not forget to close front door into the room (so as not to create drafts). It is also necessary to take this nuance into account when calculating the power of the system. To this end Q1 increase by 20% to compensate for the heat load from the supply air. It is necessary to understand that with an increase in power, electricity costs will also increase. For this reason, air conditioners are not recommended for use when ventilating rooms. At maximum high temperature(summer heat) the air conditioner may not maintain the set temperature because the heat gain may be too strong.

If the cooled room is located on the top floor, where there is no attic, then heat from the heated roof will be transferred into the room. Heat inflows from the ceiling will be much higher than from the walls, so we increase the power Q1 by 15%.

The large glass area of ​​the windows also plays a significant role. It's pretty easy to follow. It is enough to measure the temperature in the sunny room and compare it with the others. During the usual calculation, the presence of a window in a room with an area of ​​up to 2 m2 is provided. If the glazing area exceeds the permissible value. That's for everyone square meter glazing adds an average of 100-200 W.

An inverter air conditioner is well suited to operate over a wide range of heat loads. It has variable cooling power, so it can create comfortable conditions in this room.

Correspondence between model ranges and air conditioner power in BTU and kW

To solve the problem of air cooling in large buildings, it is not practical to install air conditioners in every room. This will increase energy consumption and complicate maintenance. The best option is to install a ducted air conditioner. The installation scheme of this system largely depends on the characteristics of the house.

Components

The operating principle of a duct-type air conditioner is to distribute cooled air flows from the central unit throughout all rooms. Unlike point models, it consists of several components, each of which performs a specific function.

Design

The outdoor cooling unit is designed to cool the refrigerant to the required level. Using a copper piping system, fluid is supplied to the following system elements:

1. Indoor unit. Performs the function of reducing the temperature of air pumped from the street. For this purpose, it contains a heat exchanger connected to the main line of the outdoor unit.
2. Mixing chamber. It is necessary to minimize heat losses - it mixes air masses from the street and pumped from the premises.
3. Distribution system ventilation ducts– supplies cooled air from indoor unit to the rooms. At the outlet, each of the branches is equipped with a wall grille. In some models it has the function of regulating the volume of air flow.
4. Circulation pipelines air masses outside and heated indoors.

Operating principle

Additionally, the indoor unit can be equipped with filtration and a heater for heating. This cooling principle is in many ways similar to the system. However, a duct air conditioner is characterized by lower installation costs and the possibility of installation in rooms with an average area of ​​50 m².

Installation procedure

An important point for installing air conditioning equipment is determining the optimal location for the indoor unit. The main problem is that it makes a lot of noise when operating.

Therefore, you should choose a location in the building that satisfies the following conditions:

• Maximum noise insulation from residential premises.
• The temperature should not be lower than +10°C. Otherwise, additional thermal insulation of the housing of the indoor unit of the duct air conditioner will be required.
• The length of the ventilation ducts is approximately the same. This will ensure that there is no temperature difference in the cooled air as it moves through the pipelines.

For a private home best option installation - a heated or well-insulated attic space.

Installation diagram example

The outdoor unit can be located in any convenient place - on the facade or roof of the house. Since its size and weight are much larger than those of standard split systems, installation on the roof of a building is recommended.

Selection of components

The main characteristic of the indoor unit is the volume of air passed per unit of time. This parameter directly depends on total area building and affects the dimensions of the device. Thus, the dimensions of the model with a maximum air flow of 1800 m³/hour (for cooling rooms up to 100 m²) are 1425*260*663 mm.

Household model

Next important point is the choice of air ducts. To minimize losses during the movement of air masses, it is best to choose pipes round section. However, they take up too much space. Therefore, most often they stop at rectangular channels. They are installed in a hidden way - between the rough and decorative ceiling. Therefore, the installation of air conditioning system air ducts must be done before the completion of repair work.

You should also consider the following selection features:

1. Material of manufacture. If the system is designed only for air cooling, it is recommended to choose polymer pipelines. Subject to availability additional function heating - steel.
2. The dimensions of the pipes must correspond to the dimensions of the inlet pipes of the indoor unit.
3. Location of wall grilles. Cooled air passes through the entire room. This should not be obstructed by furniture or other interior elements.

Is it possible to do the channel type yourself? You can do the installation of the indoor unit and pipelines yourself. However outdoor unit needs professional adjustment as refrigerant circulates there. Therefore, it is recommended to use the services of specialized companies for its installation. In addition, in many cases, the warranty on an air conditioner only applies if its installation is carried out by official representatives of the manufacturer.

Split system air conditioners with forced ventilation allow you to effectively solve simultaneously the problems of ventilation and air conditioning of a room throughout the year.

Split system air conditioners with forced air ventilation are equipped with standard electric heaters with a wide power range (from 5 to 20 kW). Heaters are built into the indoor unit. Air conditioners are also equipped unified system automation that controls the operation of the air conditioner and ensures its control and smooth regulation of the power of the heaters. The operation of the air conditioner (including heaters) is controlled from a single control panel installed in the room.

The fan pressure of the indoor unit is 100-150 Pa, so the units have a low noise level and can be installed directly at the entrance to the room behind the false ceiling.

Split systems with forced ventilation are designed for installation in large apartments and office spaces, shops, restaurants and other places where fresh (outside) air supply is required simultaneously with air conditioning.

A split-system air conditioner with forced-air ventilation consists of two units - a compressor-condenser unit (external unit) and an evaporative unit (internal unit). The indoor unit can take air from the room and fresh air from the street. Fresh air enters through the external grille through a thermally insulated air duct into the mixing chamber, where it is mixed with recirculated air from the room. The outer grille can be either adjustable or non-adjustable. In the latter case, an electrically driven air valve is installed in the air duct, preventing cold air from entering the room when the system is turned off. Recirculated air is taken from the room through grilles (ceiling, wall, etc.). The ratio of fresh and recirculated air is regulated by the mixing chamber and is determined by sanitary and technical requirements, as well as the operating conditions of the air conditioner. The mixed air is supplied to the indoor unit, where it is filtered, cooled or heated. The prepared air is supplied by the fan of the indoor unit to the air-conditioned rooms through a system of air ducts and distribution grilles (wall, ceiling, etc.). In one of the rooms, selected as a reference, a control panel for the entire system is installed. The remote control sets the operating mode of the air conditioner and the room temperature. The control panel sets the operating mode of the air conditioner (cooling or heating), room temperature and fan speed. Some remote control models automatically select the required operating mode, cooling or heating the supplied air. On “cold” models, air heating is ensured by smooth activation of electric heaters. On heat pump models, heating is accomplished primarily by the heat pump. In this case, heating of the premises is provided by the air conditioner by reversing the refrigeration cycle.

If the heat output of the air conditioner is not enough (for example, when the outside air temperature drops), the automation begins to smoothly connect electric heaters, achieving the required supply air temperature. When the outside air temperature is below minus 20°C, almost all heating is provided by electric heaters. The required heater power can be reduced by using recirculation, since the amount of fresh air that must be supplied to the room according to sanitary standards is significantly lower than the amount of air required for conditioning the room. As a rule, the amount of fresh air can be up to 30% of the total supply, which in most cases even exceeds the sanitary standards for fresh air supply.

The use of models with a heat pump is especially effective during the transition period at outdoor temperatures from 0°C to +15°C, until it does not work central system heating the room. At this time, the air conditioner allows you to reduce energy costs for heating by about 3 times.

A ducted air conditioning system is practically no different from a conventional split system. It consists of two modules: external and internal. External unit located on open area outside the building to ensure sufficient outside air flow. The indoor module is selected as a channel type and installed indoors.

The system is easy to use and can create a complete indoor microclimate. The indoor unit is mounted in the inter-ceiling space. Due to its hidden installation, it does not spoil designer interior and completely invisible. An air conditioner can work for more than just cooling. It also perfectly heats the room and can be supplemented with the option of introducing fresh air. Even when installing just one indoor unit, you can condition the air in different rooms. This opportunity is realized through the creation of a network of air ducts.

There are also some disadvantages of a ducted air conditioner. Firstly, such an installation takes up some space. Due to hidden installation and the need to create an air duct system, it is necessary to install suspended ceiling. Therefore, the room must be high enough. If only one indoor unit is installed, the temperature in all rooms will be the same. This problem is solved with the help of individual internal modules. But this method leads to an increase in the cost of the system. All of the above factors influence the calculation of a duct air conditioner.

Methods for selecting a ducted air conditioning system

The most popular technique is selection based on the area of ​​the room. Typically, 1000 W of cooling capacity is sufficient for 100 m². This method applicable for rooms where the ceiling height does not exceed 3 meters. Also, there should not be many people or equipment in the room that gets very hot. The error in calculations is about 30%. To obtain a more accurate result, it is necessary to apply formulas that take into account the characteristics of the room.

If the ceiling height is more than 3 meters, the selection and calculation of a duct air conditioner is carried out using a different method. The deviation in this case can be 10-15%. To get more exact result it is necessary to study special literature.

Another important factor when selecting equipment is constant (static) air pressure. In order to avoid loss of power during system operation, it is necessary to take into account the length of the air ducts, their design (turns, presence and number of receiving and distributing grilles). The static pressure of the indoor module will depend on the resistance value in the air duct. The difference must be at least 20% in favor of the indoor unit.

It is necessary to calculate the losses, which depend on the characteristics of the air duct (length, cross-section, type) and on the speed of the air flow. Gratings (receiving and dispensing) also affect productivity losses. To calculate losses more accurately, you need to use special literature.

When selecting and calculating a duct air conditioner, you need to determine in advance whether the room will be ventilated. In this case, you need to remember that it is possible to mix in no more than 30% fresh air. The calculations are influenced by the conditions under which the system is planned to operate. The air conditioner can operate stably at outdoor temperatures down to -15℃. If the equipment will operate for heating, then at temperatures below -25℃, you need to take care additional method air heating.

February 2019

Buy duct air conditioner

Duct air conditioners are not purchased online through a shopping cart! This is an element of apartment engineering or country house. Calculation of parameters as the basis of a duct air conditioning project. And based on the project - a commercial proposal and contract!

There are more than 200 models on our website! And we work with a product range of 1,500 items.

The cost of a mistake in choosing the wrong model and elements of the ducted air conditioning system is too high: the equipment, as well as air ducts, valves, booster fans - everything is sewn up under the finished ceiling. And you will either have to put up with an incorrectly or inefficiently working system, or dismantle the system. And it’s great if it doesn’t happen yet finishing premises!

How do they work and how to choose?

Duct air conditioners- this is the same split system, i.e. a block divided into 2 parts: external, for heat removal, and internal, for cooling, ventilation and supplying fresh air to the room. This is where all the similarities end.

The difference from the wall-mounted type we are used to is that the indoor unit is sewn either into the ceiling or between the walls. With such hidden installation you see only the grilles from which cooled (or heated, depending on the mode) air comes out. Cooled or heated air is supplied to the grilles through air ducts of various configurations and cross-sections - it all depends on the project.

First - technical specifications. Departures. Calculations. The result is a ducted air conditioner project

Installation of freon routes for connecting the external and internal units and the duct split systems themselves

Air ducts are being installed. Installation of valves, integration with ventilation and humidification systems

After completion of the repair - installation of decorative ceiling and wall air distribution grilles.

Installation of previously installed ceiling diffusers for ventilation and air conditioning into adapters.

You are on the website of a professional engineering company. Entrust this work to us. Ventilation, air conditioning and air quality control are our specialty!

When working on an object, we can distinguish three main stages.

No. 1. Technical specifications and design of duct air conditioning

The stage consists of receiving from the customer or jointly forming terms of reference, creating the architecture of a future engineering system, be it ventilation, air conditioning, humidification, or all combined. Analysis of data on the facility, calculation of parameters in accordance with SNiP, linking of utility networks and created communications with design solutions.

The project is the basis for the selection of equipment and materials. It is this that will form the basis of the contract for the installation of a ducted air conditioner, fixing the volume and cost of the work. With the project you are insured against “unplanned” work during the installation process!

No. 2. Installation of air ducts, fittings, freon routes and automation elements

The most complex and voluminous work. They are associated not only with the installation of external and mounting of internal split system units. Laying the freon circuit, electrics, control cables, installation of air ducts of various variable sections and shapes, adapters for duct air conditioners and diffusers, as well as slotted grilles. Condensate removal, integration with ventilation and humidification systems, installation of controls and automation. Preliminary inspection until everything is hidden under the final finish.

No. 3. Installation of slot grilles and diffusers. Commissioning and launch of the system

Cleaning work. They are carried out at the time of completion of repairs in an apartment or country house. Our task at this stage is installation decorative grilles, to which the air ducts are connected, hanging diffusers, adjusting the air flow for each separate room in accordance with the previously approved project for ducted air conditioning and ventilation. Launch and test run in all available operating modes, testing the operation of automation and control systems.

Installation of duct air conditioners

Have you seen examples of our objects? Who else if not us to entrust your apartment to? country house!?

Why Project Climate?

• personnel: full-time design engineers, site superintendents and installers of air conditioning and ventilation systems
• prices: our prices commercial offer you can search through the Internet, we are sure that you will be satisfied
• quality of work: narrow specialization in the field of climate control systems, staff training, assignment of a manager to the facility and coordinated work - the guarantee that you will be satisfied with the result of the work
• guarantee: we work under a contract, we are a dealer of most climate control brands, we have own service center repair of air conditioners and ventilation systems

Duct air conditioner: cost

The cost of installing duct air conditioners, as well as the split system itself, depends on many factors and the delivery cost can only be determined after measurements have been taken and the project has been agreed upon for calculation. consumables and definitions of types of work. When installing these systems, the concept " standard installation". Selection and calculation are made for each object individually: ready-made templates Simply no!

Often under technical solution special shaped products are manufactured (air ducts, adapters, mixing chambers, etc.). That is why in the cost section for ventilation and ducted air conditioning there is no fixed price, but only “on request” and then often after the design has been completed. We will readily answer your questions and try to help you select the required equipment for your country house or apartment and implement the project.

Remember one thing: the search engine query “buy duct air conditioner” is fundamentally wrong! You need to look for an engineering company that will carry out the work from start to finish. Buying equipment is the easiest thing possible! Just open the Internet.

And if you have already started such a request, then the following ones will be:

• buy and select air ducts
• carry out thermal insulation calculations
• place an order for the production of adapters
• purchase valves and diffusers
• installation of air conditioning system ducts
• etc. etc. - about a dozen more questions of this type

The biggest mistake will be to start from the price of the air conditioner itself. Once again: you need a system! But the components of this engineering system may be different, including the channel block itself, which with the same characteristics can be made in Japan by a manufacturer such as Daikin or budget option Hisense, Carrier, Midea type.