Advanced Air - EC Fan Coils

Epic Fan Coils - VAV Fan Coils - Energy Management Controls

Epic Fan Coil

The EPIC fan coil range provides the designer with the opportunity to achieve very low specific fan power levels (SFP). This is becoming an increasingly important issue as successive building regulations slash the allowable total carbon emission from a building.

The horizontally mounted ECM motor gives many benefits which may be summarised as follows:

• The most energy efficient fan coil unit
• Infinitely variable speed
• Variable air volume can be easily achieved with further savings in energy consumption
• Single motor as opposed to multiple motors means greater reliability
• Lower noise levels
• Ability to pre-set air volumes at the factory and fully commission the unit

VAV Fan Coils

For the last 40 years virtually all fan coils have been constant fan speed and consequently constant air volume (CAV).

Any changes in cooling or heating were adjusted by the water valve i.e. varying the water volume.

However, with the fans running at full speed all of the time this is a needless waste of energy.

By varying the air volume, significant reductions in energy can be achieved and typical values for a wide range of constant and VAV fan coils are shown in the energy comparison graph.

Controls

The control philosophy is relatively simple as can be seen from the diagram below. At maximum cooling the fan is running at 100% with the water valve fully open as the cooling load reduces the fan air volume is reduced down to a minimum of 60%. If the cooling load reduces further the water valve is progressively closed until the dead band is reached. In other words the fan air volume is reduced first followed by a progressive reduction in the water cooling volume.

On heating, the early morning boost has maximum air volume and heating. On the heating cycle, the air volume is kept constant to ensure there is no stratification within the room. The heating requirement is usually a short period just prior to occupation of the building and therefore does not significantly impact on the carbon emissions.

ECM Technology

Energy efficient brushless DC motors, as incorporated into Advanced Air’s EPIC fan coil units, give energy savings that reduce the fan power to almost a quarter of that taken by a comparable permanent split capacitor (PSC) motor. This results in a cooler running motor that transfers less heat to the supply air.

Factory setting of air volume can be set direct from the BMS system or through the in-built unique EPIC control card module. The volume can be set by a 0-10 volt control signal which, via a control system, is ideal for the utilisation of VAV capability to suit varying occupied space loads.

Due to its “smart” motor technology the fan is self commissioning as any change in external resistance is recognised by the “smart” controller and the fan automatically compensates to achieve its set point.