The first UK pressure independent fan coil unit
Advanced Air has recently launched their extended range of EPIC Fan Coil Units which all include ECM motor technology. By combining the EC motor with a unique smart card developed by Advanced Air the first pressure independent fan coil unit in the UK market is available with this feature as a standard at no extra cost.
With a pressure independent fan coil the air volume will remain constant irrespective of pressure changes. This has many advantages which include easy on site or factory setting of the air volume against a voltage signal from the controller or BMS. This means the fan coil when pre-set will give the required air volume when first installed, and as the pressure changes due to dirty filters or changes in flexible ductwork configuration the air volume remains the same.
A further benefit is the airside commissioning at the fan coil is eradicated and just a simple balance at the diffuser is all that is required.
This pressure independent feature is achieved by using a “virtual 3D Algorithm” which includes motor speed, torque, fan characteristic, and computes these via the smart card into a constant volume characteristic. As the external resistance to the fan is changed the smart card automatically adjusts the control voltage signal to the motor which changes the speed to maintain constant volume flow.
Andrew Sargent, General Manager of Advanced Air, says “This feature is unique to our company, and what’s more we include it as a standard with no extra cost. If the extra cost of some of these commissioning free options available in the market were taken into consideration savings up to 25% could be made on capital costs, i.e. the purchase price of the fan coil units. All of this can be achieved with very low specific fan power with VAV versions as low as 0.15 w/l/s and constant volume 0.2 w/l/s”.
Advanced Air manufacture their own fan decks and this has led to another unique feature which is the horizontally mounted fan deck. This allows much larger motors to be used, 250 watts compared to the conventional 75 watts, giving higher overall efficiency and much lower noise levels.