The heating surface can be an integrated part of the AHU, or be placed directly in the air intake duct. The heating surface is used to warm up outside air before being injected into the building.
Injection of air at an inadequate temperature can create a poor indoor climate due to draughts, “cold spots”, etc. In places where the injected air is not used for heating, it is injected at isothermaltemperature.
If the air is used for heating, then the size of the heating surface is calculated to produce a temperature approximately 8-10 oC higher than the temperature of the room.
The heating surface consists of a number of parallel pipes with lamellas attached. The lamellas are mounted in several rows, perpendicular to airflow. There are different types of heating surfaces:
- Water-based heating surfaces
- Steam-based heating surfaces
- Electrical heating surfaces