Equipment in a group room to control ventilation, cooling, heating and lighting via the active diffuser TTC.

The number of diffusers installed in a group room is determined by the maximum number of people allowed in the room at the same time. Schools do not normally install additional cooling. A supply air flow of at least 10 l/s and pupil is recommended. The larger active device TTC-400 allows a maximum airflow of 100 l/s. This airflow is sufficient for 10 people while maintaining a good air quality.

High flexibility

Active diffuser TTC has sensors built-in and in many cases there are no need for added installations. This gives extremely high flexibility and a simplified handling during renovation projects as walls may have to be built or moved.

With TTC, the group room is prepared for a flexible transformation into cell-offices.

A group room equipped with Lindinvent's active supply air diffuser TTC. TTC offers a solution where the climate can be adjusted with the help of a variable supply air flow and the built-in logic to control connected valve actuators.

TTC controls the ventilation using built-in sensors for presence, temperature and flow (also pressure). The external wall-mounted carbon dioxide sensor (GQ) has been installed in order to control the amount of carbon dioxide in the room. The amount of air in the room is controlled by actively increasing or decreasing the height between the lamellas in the diffuser air outlet section. Pressure and flow sensors together with an encoder on the damper motor ensure an accurate flow control. The flow is set based on 3 different flow levels: minimum flow, presence flow and maximum flow. Without attendance, the room goes into economy mode, i.e. to a minimum flow. When presence is detected, the flow is increased to the presence flow (typically 30 l / s). In the event of excess heat or CO2, the air flow is increased up to the maximum flow in order to reach set points. The built-in presence detector is used for activation after an adjustable time delay. In order to minimize the energy consumption, strongly sub-tempered air is used which reduces the need for electricity for fans.

Extract air via transfer air to a corridor

Extract air balancing takes place via transfer air to the corridor. Extract air devices are located in the adjacent corridor where the smart damper DCV-BL balances the summed supply air flow from several rooms. Supply air flows and extract air flows are communicated digitally via the CAN bus.

Additional heat or cold

A set of adjustable P-bands is used by TTC to regulate the office's climate in a way that avoids parallel heating and cooling. TTC activates the actuators for heat (SV) when the supply air cannot keep the climate in accordance with set points. There is no extra cooling system installed. A cold draft protection function can be implemented.


Signals from built-in sensors are used by TTC to regulate the room climate according to setpoints and P-bands.


TTC can flexibly control group room lighting via presence sensors or via signals from other control units. If a more advanced lighting solution is desired, with scenes etc., lighting control SBD can be used for a DALI solution.


The cable in use for linking units to a communication loop (CAN bus) is a PVC-free shielded 4-conductor combined supply and communication cable. Relay boxes and sensors etc are normally connected via connection box CBX using the same cable specification. The 4-conductors are used for power supply and signals when applicable.

Cable lengths

The CAN bus cable can be pulled long distances with respect to communication, but, for power supply to be at acceptable levels, voltage drop must be considered. See the electrical design guide.

Power supply and transformers

In a normal situation, one 230/24VAC transformer is installed per 12 to 15 diffusers/nodes on the CAN-bus section. This is a rule of thumb that applies at short distances between products. See the electricity design guide for details.

Pre-assembled smart dampers

Circular designs of the smart damper DCV-BL (as well as other circular smart dampers) are supplied with the regulator and the damper motor pre-mounted on the circular damper with measuring flange. The unit only requires connection of the controller to the combined feed and communication loop.

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