A holistic performance evaluation of ventilation radiators – An assessment according to EN 442-2 using numerical simulations

Abstract

This research explored the importance of airflow rate and convector plate design on the operational performance of heating radiators equipped with an air device (ventilation radiators). The radiator was analyzed according to European Norm EN 442-2 using numerical simulations. The largest benefit of using staggered convector plates was the more efficient preheating of the incoming outdoor air supply. With this plate design, the evaluated radiator increased the temperature of the incoming airflow of 10 l/s from -5 °C to 26 °C with water supply/return temperatures of 45 °C/35 °C. With these water temperatures, the radiator was able to cover a room heat loss of 34 W/m2 floor area. However, the design of the convector plate alone was found to have a limited impact on the heat output from the radiator. Neither did the plate design significantly affect the uniformity of heat distribution nor the vertical temperature stratification inside the room. The results also showed that ventilation radiators might cover a building heating load (kW) with a lower supply water temperature but not necessarily give a lower annual energy use (kWh) for the space heating of a building.