Genvindingsgrad

Genvindingsgrad, often translated as recovery efficiency, is a metric used to describe how effectively an energy recovery device in a ventilation or processing system transfers energy from exhaust air to the incoming air. It is central to assessing the energy performance of heat recovery ventilators and related equipment, and it helps estimate how much heating or cooling energy can be saved through recovery rather than supplied by a heating or cooling system.

The concept covers different forms of energy transfer. In ventilation, genvindingsgrad can refer to sensible energy recovery (temperature-based), latent energy recovery (humidity-based), or total energy recovery (enthalpy-based). The value is typically expressed as a percentage and depends on device type (plate heat exchangers, rotary heat exchangers, enthalpy wheels), as well as flow rates, temperature or humidity differences, and the condition of the system (filters, frost protection, fouling).

Calculation is generally described as the ratio of the energy actually transferred from the exhaust stream to the incoming stream to the energy that would be required to condition the incoming air without any recovery. In other words, it measures the share of energy saved by the recovery device. Precise calculations are device-specific and often require measurements of temperatures, humidity, and airflow, and may distinguish between sensible, latent, and total recovery.

Common devices include plate heat exchangers, rotary heat exchangers, and enthalpy wheels. Genvindingsgrad values vary widely, typically from a few tens of percent up to 80–90 percent for well-designed systems under favorable conditions. Real-world performance can be reduced by factors such as fouling, maintenance needs, outdoor climate, and frost risk.

In practice, genvindingsgrad is a key parameter in building energy performance assessments and standards for evaluating the efficiency of energy recovery systems.