With a flat duct that protrudes slightly from the ceiling, you obtain the same function as with a normal ceiling diffuser. It functions just like a standard office room and with several advantages compared to the wall diffuser: significantly better spreading, better temperature homogeneity and less risk of draughts.

This solution also works for open plan office solutions with low ceiling heights, unlike the wall diffuser. The 360 degree air spread means that problems with conflicting air streams is avoided for normal cooling requirements, which is not the case with wall diffusers.



Cellular office with supply air via the TTC active supply air diffuser that uses a built-in regulator and sensor to regulate the air quantity in the room by increasing or decreasing the slot size between the blades in the diffuser section. Extract air is transferred passively via transmitted air to the corridor. Via the CBX connection box, the supply air diffuser regulates the A4004 valve actuator on the radiator. The lighting is turned on and off either via a signal from the occupancy sensor placed in the supply air diffuser or from connected push buttons. The CBR lighting control box is used to connect push buttons and 230 VAC to the lighting.

I rooms with low ceiling heights it is also important to try to conceal the electrical installation if everything is to be visible. The cable is therefore pulled through the flat duct and runs into the side of the PBFA connection box.

Alternatively, a suspended ceiling is fitted that lies directly against the flat duct. This means that approx. 100 mm ceiling height is lost, but on the other hand all installations can be concealed beneath the suspended ceiling.


The cable used throughout is a PVC-free shielded combined supply and communication cable. It is pre-terminated in the diffuser's diffuser section with ready-made contacts in the other end for rapid installation. For other products, it is connected in the same way throughout.

Cable lengths

The bus cable can be pulled for long distances in respect of communication, but the voltage drop must be taken into account for power supply. See electricity design guide.

The limiting factor for cable length is that each CMA ("communication hub") can only have 100 nodes/products installed on it.

Power supply and transformers

In a normal situation, one transformer is installed per 12-15 diffusers/products but this is a rule of thumb that applies with short distances between products. See electricity design guide.

In some cases, you may wish to place a larger transformer in cable recesses instead of many smaller ones deployed throughout the installation. This can be done, but you must take note of the voltage drop in cables, and you will need separate thick 24 VAC cables on cable ladders...

If the CBR box is to be installed for lighting control, it is useful to use some kind of FMP bracket assembly product for pre-assembly and shorter installation times. This cannot be fitted in the diffuser box in this case, but must be placed on a cable tray on the cable ladder outside the room.

In a rectangular channel, a ceiling mounted air diffuser can be used to achieve a good mix