Trends in the development of multi-zone air conditioning systems

At the beginning 70s years of the last century, the developers of air conditioning systems faced the issue of the possibility of using energy-efficient equipment in buildings of medium and large area. At that time, the most popular and traditional solution for facilities where high cooling capacity was required was air-to-water refrigeration systems, in which chilled and heated water circulated in pipes throughout the building and cooled or heated indoor air using fan coil units. It is known that the climate equipment of a building accounts for a significant share of the consumed electricity, up to 50% of the total energy consumption of the building, so it was the problem of the high cost of operation that set the vector for creating equipment with a fundamentally different logic of operation and control. The second prerequisite was a number of technical restrictions on the use of household and multi-split systems. This concerned both the strictly established limit of routes, which should not exceed 25 meters, and a small number of indoor units connected to one outdoor unit.

Today, more than 30 years after the appearance of the first multi-zone air conditioning system, only the principle of operation has remained unchanged — a common network of freon pipelines to which indoor units are connected. Prices have dropped significantly, and the equipment itself has become much more technologically advanced and perfect, the time for its design takes only a few hours, and installation and maintenance are performed more efficiently and reliably.

For example, consider the third generation VRF system from LG Electronics, which is commercially called Multi V III and is one of the best in performance and energy efficiency on the air conditioning market.

One outdoor unit can serve up to 64 indoor units at the same time, operating in cooling or heating mode. The total capacity of the module is up to 224 kW.

The maximum length of the route is 200 m, the height difference between the outdoor unit and the indoor unit is 110 m, it does not matter how the units are installed: outdoor over indoor or indoor over outdoor. The total length of pipelines can reach up to 1000 m. These indicators are enough to effectively serve 25 storey building. These figures were achieved thanks to the continuous improvement of the process of returning oil to the compressor, because. this has always been a major problem when limiting trace lengths in VRF systems. The Multi V III uses HiPOR (high pressure oil return) technology to increase compressor reliability and efficiency by reducing losses caused by pressure differences in the circuit. The oil is returned directly to the discharge cavity using an oil pump installed inside the compressor.

Management of Multi V III is the most convenient and simple, both for the user and for the dispatcher. LG Electronics engineers have developed a whole range of solutions for managing a building or a group of buildings. For example, if a developer mounts equipment at several sites, then he has the opportunity to control up to 8192 indoor units from one control room, the distance of buildings from each other does not matter, they can be built in different cities. Self-diagnosis and monitoring functions allow you to monitor the operation of equipment without human intervention and, in case of failure, notify a service engineer by email or SMS. In other words, a modern VRF system is not only high-tech equipment with wide control capabilities, but also a cost-effective solution for many reconstructed and newly erected buildings and structures.

Another conclusion can be drawn — the modern VRF system has, in a certain sense, reached its technological maximum and the emergence of new generations of air conditioners only slightly changes its efficiency. If earlier the struggle of manufacturers was for 32 indoor units against 64, or for 500 m of the total length of pipelines against 1000 m, now the growth in indicators has noticeably decreased. However, there is development in the near future, presumably, VRF developers will pay attention to the following areas:

Temperature range extension

The operation of climatic equipment in conditions of extreme temperatures is relevant for many countries, both with hot and cold climates. The Multi V IV system, which will be presented in Russia in the third quarter of 2013, will be able to operate without significant performance losses already at -25C in heating mode and -10C in cooling mode. Energy-efficient construction can be called a consequence of the expansion of the temperature range. In European countries, the level of energy consumption of a building has been regulated for a long time. In Russia, the federal law «On Energy Saving and Improving Energy Efficiency and on Amendments to Certain Legislative Acts of the Russian Federation» came into force only on November 23, 2009. The issue of energy-efficient solutions is quite acute, because, if we talk about the operation of the air conditioning system during the warm period, we can draw the following conclusion: the decrease in external heat input to the building due to the use of modern building materials is compensated by the growth of internal heat emissions. Consequently, the cooling demand of the building will not decrease significantly, and the energy efficiency of the equipment, on the contrary, will increase.

Perfection of control systems

Control systems should be as easy to use as possible, provide the maximum amount of information for maintenance personnel and the end user, and also have the ability to alert the user of a malfunction that has occurred — this can be a message to a mobile phone or e-mail. LG Electronics specialists have developed applications for smartphones that allow for full-fledged equipment diagnostics using the Android and iOS platforms. Such a solution greatly simplifies the «communication» of the user or specialist with the air conditioning system.

Pricing

There are dozens of different brands on the Russian industrial air conditioning market, but, unfortunately, most of these brands are OEM (Original equipment manufacturer), the quality of which leaves much to be desired. The abundance of cheap low-quality equipment and components has a significant impact on the pricing policy of leading manufacturers. On the one hand, this can be a plus, on the other hand, a customer in Russia is becoming technically literate and is already looking ahead, thinking about what will happen in a year, in five or ten years. Accordingly, in the foreseeable future, a decline in investor interest in cheap products and a shift towards quality and lower operating costs is very obvious.

An integrated approach to building engineering systems

Complete solutions from a single manufacturer help customers and designers greatly simplify the process of selecting and designing equipment. The words integrated approach can be understood as providing the building with all types of engineering systems provided by one manufacturer, ranging from lighting systems to heating systems. The advantage of this approach is, firstly, a reduction in operating costs, secondly, the maximum simplification of building management, thirdly, an increase in the reliability of the engineering of the building as a whole, and fourthly, the simplification of the work of maintenance personnel with the manufacturer. For example, LG Electronics successfully implements the principle of integrated building equipment in South Korea and the United States. So, already today a number of facilities are equipped with indoor and outdoor LED lighting systems, air conditioning and ventilation systems, hot water and heating systems of our own production, which are controlled from one control room using a single software.

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Source: technical department of LG Electronics