Control of a HVAC system

SMARTech had built several EIB systems controlling HVAC (heating, ventilation, air conditioning) systems in buildings with an area of 2000 sq m (STOEN offices), and 700, 600 and 300 sq m (private houses). Each building was divided into several heating zones. The temperature in each one can be set independently (heating/air conditioning). The system also takes care of the air humidity and freshness (ventilation). Heating was executed as warm air systems via air ducts with throttles over each room. Depending on the requirement, air is pumped into the ducts according to the number of rooms. The opening of a window blocks the air uptake from the HVAC system, which influences energy savings. If no room requires heating or cooling, the ventilation starts to operate, and if the humidity sensor detects overly dry air – ventilation with air humidifier. Thermostats are integrated into the light control consoles. Each thermostat shows the current temperature in a room and allows the desired temperature to be set.

Room temperature range

The thermostat in each room is an independent control unit, sending signals about required heating or cooling in the ranges shown below. If a user changes the required temperature to a different level – then the ranges shown will change accordingly.

Ventilation and air humidity

At zero (no room requires heating and cooling), ventilation is switched on – and runs to all rooms. In case the air humidity sensor should detect that the air is dry – then the air is additionally humidified.

Open windows

If a window is open in an room – thermostat signals are blocked, and no air is introduced to the room, preventing energy losses.

The above listed features can be installed in any room. In a commercial building some of them are locked (night temperature reduction, freedom to adjust the temperature by the employees).

After hours, in the weekends and on off days, the temperature is kept at a level 6 °C lower than usually set for the room. Working hours as well as off days are programmed into the central clock. Temperatures are raised an hour before the work commences; they are also reduced after the working day is over. All temperatures are visualised, and can also be changed via this visualisation view.