Jälkilämmitys

Jälkilämmitys, often translated as afterheating or post-heating, is a term used in building physics and HVAC systems to describe a process of heating a space or air stream after it has already undergone an initial heating stage. This is typically employed to achieve a more precise temperature control or to compensate for heat losses that occur in subsequent stages of a system.

In ventilation systems, jälkilämmitys is commonly found in air handling units. After fresh outdoor air has been pre-heated, often by a heat exchanger or a primary heating coil, a secondary heating coil, known as the jälkilämmitys coil, is used to fine-tune the supply air temperature. This allows for greater accuracy in maintaining the desired indoor climate, especially when dealing with fluctuating outdoor conditions or specific room temperature requirements. It can also be used to bring the air to a comfortable temperature after it has been mixed with recirculated air that may have cooled down.

Another application of jälkilämmitys can be found in the context of industrial processes or specific building zones. For instance, a room might be initially heated to a baseline temperature, and then a supplemental heating system provides jälkilämmitys to maintain a higher or more stable temperature, compensating for heat loss through walls, windows, or exhaust systems. This technique ensures that the target temperature is met and maintained effectively, contributing to energy efficiency and occupant comfort. The control of jälkilämmitys is usually managed by thermostats and building automation systems that monitor temperature and adjust the heating output accordingly.