Split System AC - Duct System Components - (HVAC).

Split System AC. Smoke/Fire Dampers.

Smoke and Fire dampers are found in ductwork, where the duct passes through a firewall or firecurtain. Smoke dampers are automated with the use of a mechanical motor often referred to as an Actuator. A probe connected to the motor is installed in the run of duct, and detects smoke within the duct system which has been extracted from a room, or which is being supplied from the AHU (Air Handling Unit) or elsewhere within the run. Once smoke is detected within the duct, the Actuator triggers the motor release and the smoke damper will automatically close until manually re-opened.

 

You will also find Fire dampers in the same places as smoke dampers, depending on the application of the area after the firewall. Unlike smoke dampers, they are not triggered by any electrical system, which is perfect in the event of an electrical failure where the Smoke dampers would fail to close. Fire dampers may be mounted in either horizontal or vertical configurations. Vertically mounted fire dampers are gravity operated while horizontal fire dampers are spring powered. In either case, a fire damper's most important feature is known as a fusible link. A fusible link is a piece of metal that will fail at a specified temperature allowing the damper to open under gravity or spring power, effectively sealing the duct, containing the fire, and denying it the necessary air to burn.

Split System AC Installation. Plenums.

Plenums are the central distribution and collection units for an HVAC system. The return plenum carries the air from several large return grills (vents) or bell mouths to a central air handler. The supply plenum directs air from the central unit to the rooms which the system is designed to heat or cool.

Split System AC Reviews. Terminal Units.

While single-zone constant air volume systems typically don't have them, other types of air distribution systems often have terminal units in the branch ducts. Usually there is one terminal unit per thermal zone. Some types of terminal units are VAV 'boxes' of either single or dual duct, fan-powered mixing boxes of either parallel or series arrangement, and induction terminal units. Terminal units may also include either, or both, a heating or cooling coil.

Mitsubishi Split System AC. Air terminals.

Air terminals' are the supply air outlets and 'return' or 'exhaust air inlets'. For supply, diffusers are most common, but grilles, and for very small HVAC systems such as in residences, 'registers' are also used widely. Return or 'exhaust grilles' are used primarily for appearance reasons, but some also incorporate an air filter and are known as 'filter returns'.