What is a chiller: device features, selection and installation rules
When considering the cooling or heating of your own private house, it makes sense to find out what a chiller is. This alternative to air conditioning systems is practically not used for individual small rooms, but for a spacious cottage it can be a very profitable solution.
In our article, the principle of the operation of this type of climatic equipment is described in detail. The rules of assembly and construction of the system forming the microclimate in the room are given. Based on our recommendations, you can easily choose the best model.
The content of the article:
The principle of operation of the chiller
Chillers are a type of refrigeration machine that is used to cool a variety of liquids. Most often, these units are used in industry, but they are also suitable for air conditioning in large residential buildings, shopping malls, offices, etc.
In combination with fan coil fan coil units, chillers perfectly play the role of a central air conditioner. If in traditional air conditioners freon directly cools the air, then with chillers everything is somewhat different.
Here, thermal energy is transferred using ordinary water. To prevent its freezing, a mixture with antifreeze, for example, with antifreeze, can be used. The chiller works thanks to the evaporator, compressor and condenser that are part of it.
Flows of water and refrigerant pass through the evaporator. The latter absorbs the thermal energy of water and boils. The refrigerant turns into gas, and the water cools. After that, the vaporous refrigerant enters the compressor, where under the influence of compression forces it is heated and mixed with oil.
Then this composition is transferred to the capacitor, here it gives up a significant part of the thermal energy and turns into a liquid. After this, the refrigerant enters the filter drier to free itself of excess moisture.
The liquid refrigerant pressure decreases as it moves through the expansion valve. Here he again goes into a vapor state and is fed to the evaporator to repeat the cycle.
Thus, the compressor is designed to compress and move the refrigerant, which sequentially moves through the air condenser and evaporator, then heating and cooling water at the same time, then cooling.
The condenser in this system acts as a heat exchanger, with the help of which the thermal energy absorbed by the refrigerant is transferred to the environment.
Excessive pressure on the refrigerant circuit can damage the system. To control this indicator, a high pressure switch is used, as well as a pressure gauge that allows you to visually monitor the status of the system. A liquid receiver is designed to store refrigerant.
The filter drier removes not only water vapor, but also extraneous contaminants from the refrigerant. A solenoid valve is designed to control the flow of refrigerant, which automatically shuts off the system when the compressor stops working.
This protects the system from liquid entering the evaporator. As soon as the compressor starts, the valve opens. The system has a sight glass that allows you to visually monitor the status of the refrigerant.
If air bubbles are visible in the fluid flow, then it is necessary to increase the amount of freon. Sensors with color indication are designed to control the humidity of the refrigerant. And the regulation of the amount of refrigerant entering the evaporator is carried out using a thermostatic valve.
To increase system capacity, it is sometimes recommended to use a hot gas bypass valve. This item is not always included.
To ensure that the amount of water in the system remains sufficient for its operation, an automatic water topping system is installed in industrial chiller models. The circulation of water inside the circuit is provided by the coolant pump.
Previously mentioned fan coils are devices with which cooled air enters separate rooms. Install fan coil units indoors. They are mounted on the wall, ceiling and even on the floor. You can attach several fan coil units to one chiller.
Their specific number is determined by the number of rooms that need air conditioning. But at the same time, the performance of the chiller should provide a certain number of fan coil units.
For chiller and fan coil connections common water pipes are used in the overall system. This compares them favorably with traditional split systems, for which only expensive copper communications are suitable.
An important part of such a device is a pump that circulates the refrigerant. The higher the performance of this pump, the greater the distance the chiller and fan coil can separate. This is convenient because it increases the number of options when choosing the right place for the chiller.
Often the unit is placed on the roof of the building; if desired, it can be placed in a special utility room. This allows you to fully preserve the appearance of the existing facade of the building. Split systems almost never provide such an opportunity.
Chillers are classified according to various characteristics:
- by type of refrigeration cycle as absorption and vapor compression;
- by design as a monoblock or a system with a remote capacitor;
- by type of condenser cooling, which can be air or water;
- according to the connection diagram;
- by the presence or absence of a heat pump.
Chillers with a heat pump in their construction are suitable not only for air conditioning in a room, but also for heating it. They are designed for use throughout the year.
How to choose the right chiller?
For the needs of a large cottage, experts recommend using a water-cooled chiller. Such devices have a simpler design than counterparts with air cooling, respectively, and they are cheaper.
The design of the air-cooled chiller includes a fan (axial or centrifugal) for air intake from the room in which the device is installed.
To cool the condenser with water, you can use local water resources: rivers, lakes, atesian wells, etc. If for some reason there is no access to such sources, an alternative is used: a cooler made of ethylene or propylene glycol.
Chillers of this type are ideal for use in the cold season, when ordinary water simply freezes.
The choice between a chiller in the form of a monoblock, when both the compressor, the evaporator, and the condenser are enclosed in a common housing, and the option when the condenser is installed separately is not so clear. Monoblock easier to install, in addition, the performance of units of this type can be quite high.
Remote systems are mounted in different places: the chiller itself is in the utility room inside the building (even in the basement), and the condenser is outside. To connect these two blocks, pipes are usually used through which freon circulates. This explains the increased complexity of the installation of the system, as well as additional material costs for installation.
But to install a chiller with a remote condenser, less indoor space is used, and such a saving may be necessary. When choosing a suitable device, you should also consider the additional functions that the device is equipped with.
Among the popular and useful additions include:
- control and adjustment of the water balance in the system;
- water purification from undesirable impurities;
- automated filling of containers;
- monitoring and correction of internal pressure in the system, etc.
Finally, it is imperative to evaluate the chiller's cooling capacity, i.e. its ability to select thermal energy from the working fluid. Specific quantitative indicators are usually indicated in the product data sheet. The cooling capacity of each specific chiller-fan coil system is calculated separately.
In this case, the maximum and minimum temperature indicators, chiller power, pump capacity, pipe length, etc. are taken into account. These are just general recommendations for choosing chillers. In each case, you should consult with an experienced specialist who can take into account various nuances and help make the right choice.
Features of the installation of such devices
Only an experienced specialist can save on the installation of the chiller. All other owners of this device will have to pay for the services of professional installers, since in this matter any mistake can become fatal. They begin the installation with a thorough study of all technical documentation and manufacturer's recommendations.
After that proceed directly to the installation. For the chiller, you should choose a support platform that can support the weight of this device.
A frame is mounted on the site, the position of which is carefully verified using a level. If there is no site with the necessary characteristics, you should concrete the site suitable for installation, and install a frame on it.
In this case, the vibrational effect that occurs during operation of the chiller should be considered. The platform and frame must be installed so that vibration is not transmitted to other building structures. Other elements of the system may also have an impact: pipes, ducts, a hydraulic module, etc.
If the installation of the chiller is planned in the utility room inside the building, it is necessary to build a foundation for it, which will rise above the floor. This will reduce the overall inertia of the system, reduce the vibration effect, improve the distribution of mass of the unit.
The chiller itself is mounted on special spring or rubber mounts in order to dampen the vibration effect. Under these supports lay another layer of rubber, then fix the structure with anchor bolts. When deciding where to install the chiller, remember that there should be free space around the unit.
It will provide access to mechanisms for performing maintenance. In addition, air should circulate freely around the device to improve cooling of the condensers. If the chiller is installed outside the building, it must be protected from contamination, such as fallen leaves.
If debris enters the heat exchanger, this will lead to incorrect system operation and serious equipment damage. It is not permissible for the chiller to touch foreign objects or communications, as vibrations may be transmitted to them. Another important point when installing the chiller outside is the direction of the wind.
When installing indoors, it is necessary to take into account the noise impact that occurs during operation of the unit. It makes sense to take care of additional noise isolation and think about how excess noise will affect neighboring rooms. It is not recommended to install the chiller next to the living rooms.
If some other units are planned to be installed next to the chiller, care must be taken to ensure that the mechanism is not exposed to excessive heat, as well as that there are no obstacles to the free movement of air flows.
For outdoor installation of the chiller, a special casing is used, which protects the device from the effects of weather factors. An evaporator is placed inside the casing, a place is provided for the installation of compressors on the side, and a condenser is installed on top.
In the same way, the unit is installed on the roof of the building. For internal installation, the casing, of course, is not needed, but if in this case a model with a remote condenser is used, then part of the installation work is performed outside.
When studying technical documentation, attention should be paid to the installation procedure of the frame under the chiller. For some models with high performance, special vibration mounts are used, which do not need to be additionally fixed with anchor bolts.
For individual units, it is not necessary to fill in a separate foundation, it is enough to correctly install the frame and fasten the device with bolts.
Couplings are usually used to connect pipes to the chiller pipes, since the diameter of these communications is small. The chiller is connected to pipelines only after the unit is installed on the foundation and vibration mounts. You should not perform this step in advance so as not to damage the communication.
Conclusions and useful video on the topic
A video with the presentation of the industrial model of the ChA-14 chiller can be viewed here:
Industrial chiller - the device is quite complex, but with proper installation and maintenance, it can serve impeccably for many years. In order not to make a mistake during the installation of equipment, it is better to contact a specialized company.
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