Regulations: Open Fire Ventilation in England & Wales

Open fires require a considerable amount of air to burn safely and efficiently.  Under-ventilating produces incomplete combustion resulting in the production of carbon monoxide, plus the spillage of smoke and fumes into the room.  For your convenience, we have created an open fire ventilation calculator (see below) and outlined extracts from the following regulations:
  • The Building Regulations, Approved Document J (2010 edition incorporating 2010, 2013 and 2022 amendments in England) and (2010 edition incorporating further 2010 amendments in Wales).
  • For detailed guidance, refer to the full versions of the regulations linked above.
Approved Document J: Combustion appliances and fuel storage systems
Requirement: Air supply

J1: Combustion appliances shall be so installed that there is an adequate supply of air to them for combustion, to prevent overheating and for the efficient working of any flue.

Section 1: Provisions which apply generally to combustion installations

1.10: Permanently open air vents should be non-adjustable, sized to admit sufficient air for the purpose intended and positioned where they are unlikely to become blocked.  Ventilators should be installed so that building occupants are not provoked into sealing them against draughts or noise.  Air vents should not be located within a fireplace recess except on the basis of specialist advice.

1.16: In noisy areas it may be necessary to install noise-attenuated ventilators to limit the entry of noise into the building.

Section 2: Additional provisions for appliances burning solid fuel (including solid biofuel) with a rated output up to 50kW

2.2: Any room or space containing an appliance should have a permanent air vent opening of at least the size shown in Table 1.  For appliances designed to burn a range of different solid fuels the air supply should be designed to accommodate burning the fuel that produces the highest heating output.

Make an open fire ventilation calculation
Appliance Type:   
Flue or Throat Shape:    Rectangular Flue or Throat
Circular Flue or Throat
Flue or Throat Size:
  mm Wide x mm Deep

General notes:

  • This calculation assumes the air vent will be in the same room as the open fire and positioned to access directly to the outside.
  • Rytons AirCore and AirLiner ventilation sets feature anti-draught systems to promote a comfortable environment in the room.  Achieve further draught protection by placing the air vent close to the appliance or at a high level close to the ceiling.
  • Rytons through-wall stove ventilators have equivalent area calculations as required by Approved Document J and HETAS Guidelines.
  • Rytons through-wall stove ventilators are HETAS Approved for use with solid fuel, wood and bio-mass appliances.
Rytons Open Fire Ventilation Range
Achieve compliant open fire ventilation with Rytons comprehensive range of ventilators.  We are always happy to assist you with ventilation calculations and product selection; call our technical sales office on 01536 511874 for advice.
Rytons Acoustic AirCore® and AirLiner® Ventilation Sets
Rytons Unsilenced AirCore® and AirLiner® Ventilation Sets
Rytons Floor

Rytons is proud to be a family run business and British manufacturer since 1972