THE CONCEPT OF FLEXSYS

FlexSys is only concerned with cooling the BREATHING ZONE – also known as the occupied space – which goes up to 1800mm above finished floor level (FFL) when the system is working at the grille default pressure of 7 Pascals. The FlexSys system is designed to handle the entire load in the Breathing zone plus 20% of the lighting load. The heat gain not handled by FlexSys is a coil load and handled back at the Air handling Unit.

The Modular Integrated Terminal (MIT) has a good VAV high induction ratio characteristic and achieves a well-mixed condition in the Breathing Zone. The BSRIA testing indicates air is at room temperature (22°C) within 300mm of leaving the grille. This is the comfort zone for the MIT and they should therefore be positioned initially in transient spaces. If an occupant sits near to an MIT, they can reconfigure the grille. If this is still causing discomfort, the floor tile (with grille) can be repositioned.

Apart from the area around the MIT grille, FlexSys maintains 22°C at ankle height and 24°C maximum at the top of the Breathing Zone (British Council Offices Guidelines).

Multiples of MIT units are controlled in zones using Flexcool controllers, part of the YORK ISN intelligent BMS system. The temperature sensors, which are mounted at 1500mm above finished floor level, are also supplied.

The Flexcool, MIT units, sensors and BMS LAN are controlled and monitored using YORK’s Plug ‘N’ Play cable management system.

Above the breathing zone is the hot polluted air, which is drawn back through the light fittings into the return air ceiling void before returning to the Air Handling Unit or extracted to Atmosphere.

For winter operation refer to summer/winter comparison.