B Style Conceal Duct Type Fan Coil Unit

Product Overview and Working Principle of Concealed Duct Fan Coil Units

Core Function

The B-style horizontal concealed duct type fan coil unit serves as a terminal device for central air conditioning systems. It circulates indoor air through a heat exchanger coil connected to chilled or hot water pipes, delivering cooling or heating output to conditioned spaces. The unit installs above suspended ceilings, with only supply air grilles visible in the room, maintaining a clean interior appearance.

Operating Principle

Indoor air enters the unit through the return air opening, passes across the finned tube coil where heat exchange occurs with water circulating inside the pipes, and then discharges back into the room through the supply air duct and diffusers. The fan assembly provides three speed settings (High, Medium, Low) to adjust air volume according to load requirements. This unit does not transport air between rooms; each unit serves its designated zone independently.

Key Specifications and Performance Data for Ducted Fan Coil Units

Performance of Ducted Type Fan Coil (2 Tube, B Style)

Structural Features and Component Details of Horizontal FCU Units

Coil Assembly

The heat exchanger uses purple copper tubes paired with hydrophilic aluminum fins, available in 3-row or 3+1-row configurations. The 3-row design suits standard cooling and heating applications, while the 3+1-row configuration provides additional heat exchange surface area for projects requiring higher capacity output.

Fan and Motor Unit

Each fan undergoes routine dynamic balance calibration during production. The series covers air volume from 340-2380 m³/h across nine model sizes, with three fan speed settings per unit. External static pressure ranges from 12-50 Pa, supporting ducted air distribution systems of varying lengths.

Drain Pan Design

The drain pan is manufactured through a one-piece stamping process with no welded seams on the pan body, reducing potential leakage points. The surface receives spray treatment for corrosion resistance. Units are configured with standard drain connection points compatible with building condensate piping systems.

Installation Flexibility and Configuration Options for Ducted FCUs

Air Return Configurations

Three return air installation options are available: standard unit without return air box, side return configuration, and bottom return configuration. An optional return air box simplifies on-site installation work and reduces duct fabrication requirements during construction.

Pipe System Compatibility

The series supports both 2-pipe and 4-pipe hydronic systems. The 2-pipe configuration serves either cooling or heating mode seasonally, while the 4-pipe setup enables simultaneous cooling and heating availability for zones requiring year-round temperature flexibility. All models use ZG3/4" water connections.

Typical Applications and Project Scenarios for Concealed Fan Coils

B-style horizontal concealed duct fan coil units install in the ceiling plenum space of commercial buildings, office towers, hotel guest rooms, hospital wards, and residential central air conditioning systems. The concealed design suits projects requiring unobtrusive HVAC terminals that preserve interior design aesthetics. Duct connection capability allows for flexible supply air grille placement and multi-point air distribution within a single zone.

FAQ About Duct Type Fan Coil Units

How do I select the appropriate fan coil size for a room?

Selection depends on the room's cooling or heating load calculation, which accounts for floor area, ceiling height, window exposure, occupancy level, and local climate conditions. As a reference, air volume ranges from 340 m³/h for small offices to 2380 m³/h for larger open zones. Consulting with an HVAC engineer for load calculation is recommended for accurate sizing.

What is the difference between 12Pa, 30Pa, and 50Pa static pressure?

Static pressure indicates the unit's capacity to push air through ductwork. Units with 12Pa external static pressure suit short duct runs or direct discharge applications. The 30Pa rating supports medium-length duct systems with several bends, while 50Pa units serve longer duct runs with more fittings and multiple air outlets.

Can these units work with both chilled water and hot water systems?

Yes, the fan coil units operate with both chilled water for cooling and hot water for heating. The 2-pipe system switches between modes seasonally, whereas the 4-pipe configuration provides separate cooling and heating coils for simultaneous availability. Water supply temperature depends on the central plant design.

What maintenance do these fan coil units require?

Routine maintenance includes periodic filter replacement or cleaning, coil inspection and cleaning as needed, drain pan and drain line flushing to prevent condensate buildup, and fan motor bearing checks according to operating hours. Access panels in the ceiling should be planned during installation to facilitate maintenance access.