The installation of 230 COADIS 2 – HEE (High Energy Efficiency) cassette type comfort units has made a major contribution to Bluebox being the first building in the world fitted with this type of equipment to be awarded a MINERGIE® label. The use of brushless motors means that the comfort units can work at variable speed and constantly adapt themselves to the exact needs of the building.
In their HEE versions, COADIS 2 units make use of two of CIAT’s major innovations: special fan turbines, coupled with brushless technology motors. This makes energy savings of as much as 85% possible, for all the range of terminal units, be they ducted, cassette, or fan coil units. As evidence of this performance, more than 10,000 HEE comfort units are already in operation across the world just 18 months after being launched on the market.
Firstly, while previous fan models were procured off-the-shelf, the new HEE fans have been designed and developed entirely in-house by CIAT’s research teams. The geometry of the air turbines has been completely revised and numerous air-flow studies have been conducted with the specific aim of improving efficiency. Five models have been developed in order to cover the whole CIAT range. In addition, whereas previously the turbines were made of aluminium or steel, the new turbines are made of ABS and are therefore lighter. They also have lower inertia. This re-design has reduced energy consumption by 20% for equivalent air flow rates, also reducing general noise levels by 5 dBA.
Secondly, the HEE option uses a brushless motor which is more efficient, generates less noise and has a longer service life. Most importantly, these motors are fitted with an electronic board as standard, which has been developed in partnership with its supplier, enabling the motor to be controlled either by a 0-10 V signal, or by a 230 V On-Off signal. By communicating with the stator, the electronic controller directly controls the air flow supplied by the fan turbine and constantly matches it very precisely to the thermal requirements of the room, unlike competitors’ solutions which use fixed preset speeds.
“CIAT is an acknowledged leader in fan coil units. Whilst all the competitors are still working with DC motor-powered systems, CIAT is the only company offering a tried and tested solution based on brushless motors. There is a perfect match between the energy supplied by the comfort units and the needs of the building,” says Claude Favot, the building’s Design Manager.
“We worked hand in hand with CIAT’s teams, from design to installation. They helped us a great deal in the lengthy studies to determine the correct sizing of the air handling and cooling systems, which were to win the MINERGIE® label. Everything was delivered bang on time,” says Christophe Fuchs, Project Leader for INDUNI, the project contractor.
The BlueBox building is available to rent by floor or half-floor. Tenants can then change the arrangement of the comfort units, or add to them, depending on their chosen partition layout. Multiple water and air connection points are provided in the ceiling space so that they will be available where needed. CIAT’s COADIS 2 units have also been slightly oversized to reduce energy consumption further. Indeed, the cassettes thus work at lower capacity to reach the set temperature.
The solution installed in the BlueBox building is very promising. “Compare ceiling panel heating with cassettes: for a start you don’t have the risks of poor installation of the refrigerant fluid circuit, such as the reversal or crossing of pipework. What’s more, COADIS 2 units preserve the ambient air quality, with air filters fitted to each unit. Finally, they are relatively simple to move, and can therefore be positioned in just the right place, according to the tenant’s partition arrangement,” says Mr Fuchs.
Four CIAT Airtech dual flow air handling units with rotary air recovery, with a flow of 45,000 m³ per hour, were also installed to manage air renewal. The rotary recovery enables 80% of the heat energy from the outgoing air to be recovered to heat the incoming air. The system also includes two 640 kW Aquaciat 2 chilled water production units. By using two small units, rather than a single larger one, electricity consumption is optimised, using just one unit most of the time and starting up the second one only during peaks in consumption. The building’s equipment is monitored by a Building Management System with a LON-bus.
Key to photos:
-BLUEBOX.jpeg: the first MINERGIE® certified building using cassettes
-COADIS.jpeg: COADIS 2 cassette type comfort units
-COADIS 2.jpeg: COADIS 2 cassette type comfort units
-COADIS 3.jpeg: COADIS 2 comfort units can easily be moved according to needs
-CTA.jpeg: Airtech double flow air handling unit
-ECH ROTATIF.jpeg: rotary air recovery
-AQUACIAT.jpeg: Aquaciat 2 chilled water production unit