Poistolämmitys

Poistolämmitys, also known as exhaust air heat recovery or extract air heating, is a ventilation system that recovers heat from exhaust air to preheat incoming fresh air. This system is commonly integrated into mechanical ventilation units. The primary function of poistolämmitys is to improve the energy efficiency of a building by reducing the energy required to heat fresh air introduced into the building.

The process involves drawing warm, stale air from a building, typically from areas like bathrooms, kitchens, and utility rooms. This exhaust air then passes through a heat exchanger. As the exhaust air flows through the heat exchanger, it transfers a significant portion of its thermal energy to a separate stream of cold, fresh outdoor air. This preheated fresh air is then distributed throughout the building, reducing the load on the primary heating system.

Poistolämmitys systems can significantly reduce heating costs, especially in colder climates. They also contribute to improved indoor air quality by ensuring a continuous supply of fresh, filtered air. The efficiency of the heat recovery can vary depending on the type of heat exchanger used and the design of the ventilation system. Modern systems often achieve heat recovery rates of 70-90%. This technology is a key component in many energy-efficient building designs, including passive houses and low-energy homes.