HUMIDITY - DE LUXE

Condense Detector, Chilled Beams - advantages

During the last decade, the technology for chilled beams has been refined and improved and has been more widely applied.

As well as reducing energy consumption, chilled beams improve comfort levels by lowering the potential for draughts and cutting out the intrusive noise and aesthetic problems associated with more conventional solutions, such as mechanical ventilation and air conditioning.

The fact that chilled beams are water-based systems makes them environmentally attractive, and because they are unobtrusive installations, they free up more valuable office space for occupation and use.

Chilled beams and chilled ceilings are not appropriate for every building project, but there are a number of applications where they are ideal like in:

• Commercial office developments

• Hotels

• Hospitals

Controlling Chilled Beams
Altering the rate at which air is supplied via an active chilled beam is one method of controlling the output, reducing potential over cooling and meeting C0₂ requirements in spaces.

Another is to vary the temperature of the air supplied. Condensation detectors should be considered to ensure that condensation does not occur.

Also that the total air supply to the space can deal with the design range of floor occupation density within the comfort criteria specified.

Chilled beams and ceiling systems are
typically designed to use the dry cooling principle by selecting the ventilation rate, supply air conditions and chilled water flow temperature so that no risk of condensation exists.

The space air dew point temperature should be around 2° C lower than the flow temperature of chilled water in the ceiling or beam system.

The following precautionary control can be implemented in the BMS to avoid condensation:
Space relative humidity is monitored to ensure the chilled water flow temperature is controlled above the calculated dew point.

Condensation sensors can be utilized to shut off the chilled water supply when condensation is detected, this is recommended, especially when windows are openable to external air.

In the absence of condensation sensors, openable windows should be equipped with window switches that trigger chilled water control valves to shut-off.

Difference between WCD2 and WCD single:

WCD2

• VFC and current output

• LED indication

WCD single

• Only VFC output

• No LED indication