The dual duct system is another means of providing varying air temperatures to different rooms in the same building. There is no water circulation to peripheral discharge units with terminal reheaters or coolers. This simplifies the plumbing installation as heating and cooling elements for each duct are located in the plant room. However, the system is space consuming and adequate provision must be made in suspended ceilings or raised flooring to accommodate both distribution ducts. The system is most energy economic when heating and cooling elements operate individually. For some of the year this will not be practical and simultaneous delivery of cold and hot air is provided for blending at the point of discharge.
Delivery is at high velocity with hot and cold air regulated by a damper connected to a room thermostat. A control plate in the mixing unit maintains constant air volume. As with all systems of air conditioning, fire dampers are required where the ductwork passes through compartment walls and floors.
FREQUENTLY ASKED QUESTIONS
In a dual duct system, simultaneous delivery of cold and hot air is provided for blending at the point of discharge. This is achieved through high-velocity delivery with hot and cold air regulated by a damper connected to a room thermostat. A control plate in the mixing unit maintains constant air volume, ensuring efficient and comfortable temperature control.
A dual duct system consists of two main components: the hot air duct and the cold air duct. These ducts are typically located in the plant room, where heating and cooling elements are installed. The system also includes dampers, room thermostats, and control plates to regulate air flow and temperature. Fire dampers are also required where the ductwork passes through compartment walls and floors.
The dual duct system requires careful consideration in building design and architecture, as it demands adequate provision in suspended ceilings or raised flooring to accommodate both distribution ducts. This can impact the overall aesthetic and functionality of the building, particularly in terms of ceiling height and floor space. However, the benefits of the system, including improved energy efficiency and flexibility, can outweigh these design challenges.
Yes, the dual duct system can be used in conjunction with other HVAC systems, such as variable air volume (VAV) systems or fan coil units. In these hybrid systems, the dual duct system provides the primary heating and cooling, while the other systems provide supplementary or localized temperature control. This can enhance overall system efficiency and flexibility.
Regular maintenance is essential to ensure the optimal performance and efficiency of a dual duct system. This includes cleaning and inspecting the ducts, checking and replacing air filters, and verifying the proper operation of dampers and control plates. Additionally, the system’s heating and cooling elements should be regularly serviced and maintained to prevent energy waste and ensure reliable operation.
