3.2.2 Ventilation

Natural or forced (mechanical) ventilation can be used to prevent the formation of potentially explosive mixtures. Natural ventilation is the preferred method due to its intrinsic reliability.  If forced ventilation is used, then the reliability of the system has to be considered.

Appliances which are not fitted with devices such as flues to avoid a dangerous accumulation of unburned gas or combustion products in indoor spaces and rooms should be used only in areas where there is sufficient ventilation to avoid accumulation to dangerous levels.  Most EU member states have national regulations specifying the ventilation and flueing requirements for gas appliances; however, these may not be applicable to hydrogen or fuel cell systems.