The exhaust air is drawn in and passed through a heat exchanger, which then heats the incoming cold fresh air with the warm air before being supplied to the sauna at a temperature of, for example, 40°C to 55°C, instead of approximately 20°C. The energy required to reach, for example, 80°C is then significantly less. The warm air can also be used to heat other areas of the wellness facility. The same system configuration is suitable here, with the difference that the heated fresh air is then routed to distant areas via pipes and ventilation ducts. The airflow can be regulated with numerous individual fans or dampers. Modular designs can significantly reduce costs but are only truly practical for large systems. The ventilation systems can also be managed and controlled via displays or remote access; please contact us for more information.