43
VENTILATION REQUIREMENTS OF COMMERCIAL
BOILERS OVER 70kW NET INPUT
OPEN FLUED APPLIANCES, TYPE B & C IN PLANT ROOMS
OPEN FLUED APPLIANCES, TYPE B IN PLANT ROOMS
(ADDITIONAL RECOMMENDATIONS)
OPEN FLUED APPLIANCES, TYPE C IN PLANT ROOMS (ADDITIONAL RECOMMENDATIONS)
FLUE TYPE
VENTILATION DIRECT TO OUTSIDE AIR
(cm² per kW net heat input)
HIGH LOW
OPEN (TYPE B) 2 4
OPEN (TYPE C) 2 2
Natural Ventilation cm² kw (net) heat input for open flue boilers located in a boiler house
(A) Boiler House (B) Enclosure
Summer usage*
greater than 50% up
to 75%
Summer usage*
greater than 75% up
to 100%
High 2 5 +1 +2
Low 4 10 +1 +2
*for boilers in use for more than 50% of the time during the summer months, additonal ventilation needs to be
added to those in columns A and B
Natural Ventilation cm² kw (net) heat input for open flue boilers located in a boiler house
(A) Boiler House
(B) Enclosure
Summer usage* greater
than 50% up to 75%
Summer usage* greater
than 75% up to 100%
To a room
or internal
space
Direct to
outside air
High 2 10 5 +1 +2
Low 2 10 5 +1 +2
*for boilers in use for more than 50% of the time during the summer months, additonal ventilation needs to be
added to those in columns A and B