Investigations in i.a. schools show how the attendance rate in different types of spaces is generally low, which means that a system that adjusts ventilation and air conditioning as needed can save up to 80% of the fan energy and 40% of the heating and cooling energy. In addition, the system usually requires smaller ventilation units and cooling machines, which reduces the investment cost. The same is true for many other types of premises, e.g. offices, housing and hotels.
Attendance in the classroom during school hours
TeknDr. Dennis Johansson, Presence in Buildings - Measurements and Estimates, 2010
It is clear here that it is not sustainable from an energy and environmental perspective to ventilate at full power around the clock. This is not necessary even during the most active hours of the day. There are systems that help to keep energy consumption low, the economic savings high and the indoor climate excellent. A simpler VAV system may be fully sufficient in smaller projects where the requirements picture is not so advanced and the cost of investment a decisive factor. For projects where the demands on the indoor climate are higher and the building possibly. To be certified according to any green or wellbeing based building program, more advanced DCV systems are required!
The past few decades have meant major changes in where and how most of us spend our days, but we humans basically function the same way they did thousands of years ago. By starting from the human being when we design our indoor climate systems, we can keep comfort high, which positively affects both our performance and our long-term health.