SUMMERTIME COOLING WITH VENTILATION RADIATORS

Ventilation radiators, heat emitters where cold ventilation air is brought directly from outdoors into theroom via heated radiator surfaces, are becoming more and more common in Scandinavia. Becausethese systems combine both heating and ventilation several interesting aspects arise that may be usedto save energy and improve indoor thermal climate. The heating aspects in wintertime have beendiscussed in previous papers from KTH STH. This study investigates whether ventilation radiators maybe used for cooling in summertime.Results from the study show that condensation of water is the main problem to tackle whenventilation radiators are used for cooling purposes. It is difficult to avoid condensation, especially insidethe ventilation channel where incoming ventilation air comes into contact with chilled radiator surfaces.The problem increases with increased temperature difference between radiator surface and ventilationair. This is why ventilation radiators seem unsuitable for cooling in summertime without riskingcondensation of water.However, if condensation of water is allowed in the ventilation channel only, ventilation radiators maybe functional for cooling. The trick is to find a way to drain water from the ventilation channel to avoidhygiene problems.