Introduction

A good air supply is essential to the safe working of a heat producing appliance.  The amount of air required will depend on the type of appliance, the input/output and the type of fuel it burns.  For your convenience, we have outlined extracts for two popular gas appliance installations from the following regulations:

Technical Guidance Document J: Heat Producing Appliances

Requirement: Air supply

J1: A heat producing appliance shall be so installed that there is an adequate supply of air to it for combustion, to prevent overheating and for the efficient working of any flue pipe or chimney serving the appliance.

Section 1: Provisions which apply to all fuel types

1.2.6.3: Where ventilation is provided via a proprietary ventilator the equivalent area, as declared by the manufacturer when tested to I.S. EN 13141-1:2004, should be equal to not less than 80% of the required permanent free area.

1.2.7: A permanent opening should be positioned where it is unlikely to become blocked or cause discomfort from cold draughts…  Openings should not be located within a fireplace recess except on the basis of specialist advice.

Section 3: Additional provisions for fixed gas burning appliances with a rated input up to 70 kW and for gas burning cooking appliances

3.5.1: Flueless appliances: When locating any flueless appliance reference should be made to Table 3 and I.S.813:2014 for locations permitted and air supply required as combustion products from these appliances are released directly into the room where they are located.

3.5.2: Open-flued appliances: Any room or space containing an open-flued appliance should comply with the requirements as set out in Table 4 for permanent ventilation openings.

3.5.3: Additional guidance regarding the size and positioning of ventilation openings, including guidance for when there is more than one open-flued or flueless appliance in a room or space and for when the appliance is situated in a compartment is contained in I.S. 813:2014 and I.S. 820:2010.

General notes: