Ventilation requirements for flueless gas appliances

Table 4.1 Ventilation for flueless gas appliances Flueless appliance type | Maximum appliance rated heat input | Volume of room, space or internal space (m³) | Free area of permanently open air vent (mm²) Cooker, oven hotplate or grill or combination thereof | Not applicable | < 5 | 10000 | | 5 to 10 | 5000 | | > 10 | no permanently open vent needed Instantaneous water heater | 11 kW (net) | < 5 | Installation of water heater not permitted | | 5 to 10 | 10000 | | > 10 to 20 | 5000 | | > 20 | no permanently open vent needed Space heater not in an internal space | 0.045 kW (net) per m³ volume of room or space | All cases | 10000 PLUS 5500 per kW input (net) in excess of 2.7 kW (net) Space heater in an internal space | 0.090 kW (net) per m³ volume of internal space | All cases | 10000 PLUS 2750 per kW input (net) in excess of 5.4 kW (net) Notes: (1) An internal space means one which communicates with several rooms or spaces, such as a hallway or landing. (2) For LPG fired space heaters conforming to BS EN 449: 2002+A1 the recommendations of BS 5440: 2 should be followed. (3) No permanent opening required if the room has a door that opens directly to outside. (4) No permanent open air vent is required if the room or space has a door which opens directly to the outside. 5. The permanent ventilation provisions listed in this table are additional to the openable elements or (for kitchens only) extract ventilation in accordance with Part K.