Introduction to the Application of End - product, Fan and Motor Characteristics (Fan - coil Unit Section)

Introduction to the Application of End - product, Fan and Motor Characteristics (Fan - coil Unit Section)

Fan - coil Unit System: It is an all - water system commonly serving the perimeter zones of buildings. This is a widely applicable and cost - effective system, which can be used to handle some independently controlled zones in buildings with different load characteristics.

Current Fan - coil Unit Types in the Market
Installation Positions of Different Types of Fan - coil Units
Vertical Unit: Installed visibly or concealed under the window.
Horizontal Unit: Installed visibly or concealed on the ceiling of the corridor.
Column - type Unit: Installed visibly or concealed from floor to ceiling with water pipes inside.

Embedded Unit: Inlaid in the wall - with a panel.

Common Fan - coil Units in the Market:
Basic Components of Fan - coil Units:
Basic Parameters of Fan - coil Units: Air volume, cooling capacity, heating capacity, static pressure, noise, water resistance, input power, water supply, and temperature difference between inlet and outlet water.

Basic Parameters of Fan - coil Units and Their Conversion Relationships:
Fan - coil Unit Air - conditioning System:
Water Pipe Distribution System:
Switchable Two - pipe System: Standard fan - coil unit.
The switchable two - pipe system has one supply pipe and one return pipe, connected to the coil of the room terminal device. The two - pipe system is used in temperate regions with very small heat loads. During normal system operation, there is cold water or hot water circulating in the pipeline. However, it is impossible for cold and hot water to circulate simultaneously in the pipeline. The system must be switched twice a year, in spring and autumn. This may cause discomfort in the rooms at certain times of the year. For example, some rooms need heating while some need cooling. Sometimes, the problem can be solved by zoning the pipeline system, but this is not always feasible.
Adding an auxiliary electric heating coil to the two - pipe system can solve the problem of discomfort in the rooms. In this way, the system can use cold water all the time until the outdoor conditions require heating, and then the system switches from cooling to heating.
Non - switchable Four - pipe System: Combined - coil fan - coil unit.
The four - pipe fan - coil unit system is so named because it has a cold - water supply pipe, a cold - water return pipe, a hot - water supply pipe, and a hot - water return pipe, with a total of four pipes connected to the indoor fan - coil unit device.
The indoor device can choose either two coils with valves or one coil with special three - way valves at both the inlet and outlet. The choice between the two forms only depends on the difference in the total cost of the terminal device and the control valves.
Since the four - pipe system can enable the terminal device to heat or cool simultaneously, the indoor environment remains satisfactory at all times, regardless of changes in the indoor load.

Sources of Fresh Air:
Infiltration (a): -- Method of the all - water system.
Fresh air introduced through a wall opening (b): -- Effect of wind pressure.
Independent fresh - air system (c): -- The best method.
Inner - zone extension (d): -- Mixed air of the return air from the inner - zone air - conditioning system and outdoor fresh air.