Fan-coil unit
an alternative discharge unit for application to the induction system shown on the previous page. Instead of nozzle injection of air, a low-powered fan is used to disperse a mixture of primary and secondary air after reheating or cooling from an energy exchanger within the unit.
Induction diffuser
another alternative which also uses a blend of recirculated room air with primary air. These locate at the end of branch ductwork and combine a diffuser with a simple primary and secondary air mixing chamber. The high-velocity primary air mixes with low-velocity secondary air drawn into a plenum ceiling from the room below. Light fitting extract grilles may be used to some advantage in this situation.
FREQUENTLY ASKED QUESTIONS
A fan coil unit works in conjunction with an induction diffuser to distribute conditioned air throughout a building. The fan coil unit reheats or cools the air, which is then dispersed by the induction diffuser into the occupied space. The induction diffuser uses the momentum of the primary air to induce a flow of secondary air, creating a high-velocity jet of air that can penetrate deep into the space.
The advantages of using a fan coil unit over a traditional air handling unit include lower capital costs, reduced energy consumption, and increased flexibility in terms of layout and design. Fan coil units are also generally quieter and more compact than traditional air handling units, making them ideal for applications where space is limited.
The design of a fan coil unit has a significant impact on its performance and efficiency. Key design factors include the type and size of the fan, the coil design and configuration, and the layout of the unit. A well-designed fan coil unit can provide high airflow rates at low pressure drops, while also minimizing energy consumption and noise levels.
Fan coil units are commonly used in commercial and residential buildings, including offices, hotels, hospitals, and apartments. They are particularly well-suited for applications where there is a need for individual zone control, such as in hotels and apartments, or where there are specific air quality requirements, such as in hospitals.
Fan coil units compare favorably to other types of air distribution systems, such as VAV (Variable Air Volume) systems, in terms of energy efficiency and cost-effectiveness. While VAV systems can provide more precise control over airflow rates, fan coil units offer a simpler and more cost-effective solution for many applications.
Key considerations for selecting and sizing a fan coil unit include the required airflow rate, the available power supply, and the noise level requirements. It is also important to consider the specific application and the desired level of zone control, as well as any specific air quality or filtration requirements.
