A good indoor climate creates a good environment for your workforce.
A good working environment can make a big difference for the individual enterprise: studies have shown that a poor indoor climate can affect productivity by as much as 15%.
In an open-plan office with large numbers of workers, heat emissions will be high, not to mention the heat given off by computers, etc. There also may be large sunlit glazed areas which also help to make the air hot and heavy.
Ventilation removes the air pollution caused by people and machines and replaces it with new, fresh air. This gives a greater feeling of well-being, and, all things being equal, makes employees more productive. The number of errors made goes up as temperatures rise above the 20 - 22°C.