The Recair Sensitive series is a unique series of patented heat exchangers for use in modern ventilation systems. These heat exchangers withdraw heat from one air current and transfer this heat to another air current. This enables the recuperation of up to 93% of the present heat. In order to meet modern-day requirements, for instance DIN 4719 in Germany, Recair now places an aluminium grid over the inflow surfaces of the exchanger to prevent ignition of the plastic. Independent research bureau Efectis, part of TNO, carried out several flammability tests on Recair products where flammability was determined in case of direct exposure to flames. This indicated that the heat exchangers passed all seven tests with flying colours, thus meeting both the ISO 11925-2:2002 and NEN-EN 13501-1:2007 norm.