Supply air temperature must be equal to room temperature.
It cannot be said that designers are doing ventilation wrong — but in many buildings, solutions could definitely be significantly better.
Today, mixing ventilation is still the default solution in most projects, yet it comes with several practical drawbacks:
• Unsightly dust marks often appear on ceilings or walls around supply diffusers.
• Ventilation efficiency suffers — exhaust air terminals are frequently placed where people rarely stay, while supply air is blown directly onto occupants.
• In practice, fresh air is mixed with polluted indoor air, and additional energy is then required to remove that mixed air from the building.
• Supply diffusers and cooling placed above occupants may create uncomfortable drafts.
• In commercial buildings, supply air is often heated to match room temperature while the space is simultaneously cooled — an energy-intensive and contradictory approach.
How to achieve a better and more energy-efficient solution with minimal effort?
✔ Use free-flow supply air with linear air diffusers.
They are more aesthetic and can be installed near windows and away from occupants. This also prevents visible dust marks around diffusers.
✔ Place exhaust terminals above occupants and pollution sources.
Contaminated air is removed directly at its source instead of being mixed throughout the room.
✔ Keep supply air temperature 3–4°C lower than room temperature.
This creates a natural temperature gradient: fresh air moves downward while polluted air is extracted without excessive mixing.
✔ Add demand-controlled exhaust ventilation.
This significantly improves indoor air quality while reducing energy consumption. Suitable ventilation dampers for this purpose are produced locally in Estonia.
The result:
better aesthetics • healthier indoor climate • lower energy use • smarter ventilation