Several Precautions for Selecting Fan - Coil Units

Fan - coil units are important components in large - scale central air - conditioning systems. Their selection directly affects our usage, such as cooling effect, power consumption, noise impact, etc. To evaluate these aspects, we can choose the corresponding specifications according to some parameter indicators of the fan - coil units. The following lists several precautions for selecting fan - coil units of large - scale central air - conditioning systems for sharing with you.

Nowadays, many people in the industry believe that the technology of fan - coil units has long been mature and the product quality is more or less the same. Therefore, the only thing to choose is the brand. However, they are unaware that the motor power of fan - coil units is a factor that must be considered. Comparing the motor power of some units, the difference between two units can be 13W. Taking the fan - coil units in a certain area as an example, if they operate 10 hours a day and 200 days a year, 26 kWh of electricity can be saved annually. If there are 500 such fan - coil units in a building, it will also be a significant expense over a year. Although there is a certain price difference in the initial investment, the increased initial investment can be recovered in about 3 years. Everyone knows which option is more cost - effective when calculating this economic account.

Currently, in specific engineering designs, we often select fan - coil units by referring to the samples of relevant manufacturers based on the calculated cooling load.

How to consider the air volume of the coil is a problem. Most manufacturers in the domestic market only offer three - row - tube coils, but some also provide two - row - tube coils. For most civil building air - conditioning systems, choosing two - row - tube coils is more advantageous (except for high - humidity occasions). This is because the two - row - tube products have a larger air volume under the same cooling capacity, which will increase the air change rate of the air - conditioned room and is conducive to improving the air - conditioning accuracy and comfort. Under the same cooling capacity, supplying air with a small temperature difference and a large air volume will achieve a better air - conditioning effect than supplying air with a large temperature difference and a small air volume.

Generally, the parameters of fan - coil units in samples are obtained under the condition of 0 static pressure.

In actual use, a short section of air duct and air - outlet louvers are often connected in front of the air - outlet of the coil. In addition, some projects are also equipped with a return - air box. Therefore, in actual use, it will be found that the actual air volume of the coil is smaller than its nominal air volume. The consequence of this is that the air volume in the room decreases, the supply - air temperature difference increases, and the comfort of the air - conditioning system drops. Some designers, to avoid this situation, select the coil according to its medium - grade air volume during the selection process to avoid insufficient air volume, but this increases the initial investment of the project. Therefore, the author suggests that, under the condition that the domestic test standard has not been changed, when selecting the coil, we should give priority to units with a residual pressure (generally 10 - 15Pa).

The noise problem is the most frequently complained - about point during the use of air - conditioners.

The main reasons for this problem are the unreasonable configuration and matching of the motor and fan in the coil. In addition, it is also due to the loose quality management of the manufacturer and the weak sense of responsibility of the assemblers, resulting in unstable product quality.

When selecting according to the design, it is necessary to choose a model with sufficient cooling capacity. Some manufacturers may have production process deviations during processing, which may lead to failure to meet the cooling requirements. This is especially true for the outer areas with a large heat load. Therefore, the cooling capacity is also one of the important indicators for selection.

In addition to the above points, we also need to consider from the appearance aspects, such as whether the air - handling unit has overall insulation, whether the length of the water - collecting tray is sufficient, etc. Choosing reliable products can make people feel at ease when using them.