How does fan coil processing achieve "dual use"both cooling and heating—in modern building air conditioning systems?
Publish Time: 2025-08-20
In modern building air conditioning systems, fan coil processing, with its compact structure, flexible operation, and high comfort, can deliver both cool air for indoor cooling and hot air for winter heating, truly achieving "dual use" in one unit.1. Basic Structure: The Collaborative Operation of the Fan and CoilFan coil processing consists of two main components: the fan and the coil (i.e., heat exchanger). The fan forces air circulation, drawing indoor air into the unit, passing it through the coil for heat exchange, and then blowing it back into the room. The coil is a metal piping system that flows hot or cold water. It typically consists of copper tubes strung with aluminum fins to increase the heat exchange surface and improve heat transfer efficiency. When the fan is running, air flows over the coil surface, exchanging heat with the medium (water) flowing within the tubes. If the pipes contain cold water, the air is cooled and dehumidified, achieving cooling; if the pipes contain hot water, the air is heated, achieving heating. The entire process does not rely on direct evaporation or compression of the refrigerant, but rather uses water as a "heat transporter" to transfer energy.2. The Key to Switching Between Cooling and Heating: Flexible External Heat Source SupplyFan coil units themselves do not generate cooling or heating; they are merely "end-of-line heat exchangers." Their cooling and heating functions rely entirely on chilled or hot water supplied by an external central system. This heat source is typically provided by a heat pump, chiller, or boiler system. In summer, the chiller or heat pump operates in cooling mode, pumping chilled water (typically 7°C to 12°C) through the coils of each fan coil unit, absorbing heat from the room and achieving indoor cooling and dehumidification. In winter, the heat pump switches to heating mode, or the boiler heats hot water (typically 60°C to 65°C) and pumps it through the coils, releasing heat to the room and providing heating. By switching the water system temperature, the fan coil unit automatically switches functions, truly achieving "two functions in one."3. Flexible System with Support for Zoned ControlAnother major advantage of fan coil systems is their ability to be independently controlled. Each room or area can be equipped with a separate fan coil processing system and equipped with a thermostat, allowing users to adjust temperature, fan speed, and operating time according to their needs. For example, a conference room can heat during the day and automatically shut down at night when unoccupied. Guest rooms can also be individually activated and deactivated based on occupancy, avoiding energy waste. This "centralized cooling/heating, decentralized regulation" model ensures efficient energy system operation while enhancing flexibility and comfort, making it particularly suitable for buildings with diverse functions and varying usage schedules.4. Quiet Operation and Diverse Installation OptionsSince the core cooling/heating equipment (such as chillers and heat pumps) is typically centralized in the machine room or on the roof, fan coil processing operates solely with the fan itself, resulting in lower noise levels. This makes it particularly suitable for locations requiring a quiet environment, such as hotel rooms and offices. Furthermore, fan coil units offer a variety of installation options, including concealed horizontal installation (hidden in the ceiling), exposed installation, vertical installation, and wall-mounted installation, allowing for flexible selection based on building space and decor requirements, saving space while maintaining aesthetic appeal.5. Maintenance and Energy Saving: Guaranteeing Efficient OperationTo ensure long-lasting and stable cooling and heating performance, fan coil units require regular maintenance, such as cleaning the air filter, removing dust from the coil surface, and checking the condensate drain for unobstructed operation. Dust accumulation can impair heat exchange efficiency, while clogged drain pipes can cause leaks. From an energy-saving perspective, water systems offer high heat capacity and low transport energy consumption. Combined with variable-flow pumps and intelligent control systems, they can significantly reduce overall energy consumption. This is especially true when using air-source or ground-source heat pumps as the heat source, resulting in high energy efficiency and environmental friendliness.The key to fan coil processing's dual-use capability lies in its use of water as the cooling and heating medium. The water supply temperature is adjusted via an external system, and the fan forces the air to exchange heat with the coil, resulting in flexible cooling or heating output. It is not only a highly efficient terminal device in a central air conditioning system, but also an intelligent solution for achieving year-round comfort.
