Overview
The seven large wind towers sit on the two sides of the school and designed to provide natural ventilation to all the classrooms on three levels. Due to the location next to the railway line noise is prevented entering the school through large rectangular acoustic pods that hang below the main roof turret.
Climbing up through the centre of the acoustic module is an access hatch that allows access into the top part of the tower. When the door is closed this forms a safe working platform. On each of the four faces is an external fixed weather louvre with an internal motorised damper mounted on the back. A short cased axial extract boost fan is then mounted behind the damper that activates when excessive temperature in the school is exceeded.
During the day heat builds up in each classroom; cool air enters the room from high level windows, as its warms it is drawn across the room and exits into the open three storey corridor / atriums. The passive stack assisted by external wind pressure creates a negative draw that causes the air to rise being exhausted through the towers on the leeward side of the prevailing wind.
Problems
For twenty years the system has operated flawlessly with Vision attending twice a year to service and ensure all the dampers can be opened both from the BMS and inside the tower during routine lubrication. Over the year debris accumulates on the damper blades and pivot points that increase friction preventing the damper motors from operating and causing them to come loose affecting the functionality of the complete system.
Solution
To keep the system working we inspect all dampers and remove the accumulation of dust and debris from the damper blade pivot points and then lubricate all moving points and test via the BMS that they all open and close. Like all moving equipment simple routine maintenance is the key to longevity. After 20 years of constant use the towers are in remarkable condition all due to a bit of simple lubrication.
