Once upon a time I worked as a electrician in a manufacturing plant. Plants office manager asked me to overlook one of their open office rooms, there was something funny about it's ventilation/heating. That is what i discovered:
At the beginning, when building was constructed, that room had standard ventilation like all other rooms. Hot/cold water heat exchanger hidden in ceiling that cooled/heated air. Fast forward some years, people change in the office and knowledge, how to change temperature setpoint was lost (i never found control panel). People wanted to control temperature, and big electrical air conditioner was installed.
Sadly, ceiling ventilation and air conditioner had different temperature setpoints. Thus they fought each-other. One of them tried to cool and other tried to heat. Resulting temperature was not what workers wanted, thus they had electrical radiators besides their desks (apparently cooling ventilation won).
In the end there were three different heating systems in one office. A fragile peace between three systems.