Schiedel : UK: Sizing

Use the wizard to determine the required size, or if you prefer you can refer to the table below.

Flue Sizing Wizard

	80 mm	100 mm	130 mm	150 mm	180 to 400mm
Gas - Atmospheric Boiler
Input up to 25kW		•
Input 25kW-40kW			•
Input 40kW-60kW				•
Gas - Commercial/Industrial Boilers
Input up to 50kW to 70kW					•2
Gas Fires
'Radiant' - BS7977-1 2002			•
'Inset' - BS7977-1 2002			•		•1
'Backboiler' - BS7977-2 2003			•
Gas Water Heaters
Input up to 25kW	•	•
Input 25kW to 55kW			•
Input 55kW to 60kW				•
Input over 60kW					•2
Gas Warm Air Units
Input up to 18kW		•
Input 18kW to 35kW			•
Input 35kW to 60kW				•
Input over 60kW					•2
Gas Stove/Cooker		•2	•2	•2
Kerosene (28 sec Class C2) Heating Boiler
Output up to 25kW		•
Input 25kW to 45kW			•
Input 45kW to 70kW				•
Kerosene Stove/Cooker		•3	•3	•3
Kerosene Water Heater
Input up to 41kW				•
Kerosene Visual Effect Stove
Input up to 17kW		•3	•3

KEY TO ANNOTATION IN TABLES
1 Subject to appliance manufacturer's testing criteria.
2 Subject to manufacturer's input rating and chimney height.
3 Subject to manufacturer's output rating and chimney height.
4 Min 300mm depending on opening, chimney size and height.
S Smokeless fuel only.
SC Smokeless fuel or coal.

This information and sizes are provided as a nominal guide only. Flue sizing for appliances, particularly commercial/industrial applications will vary depending on siting details and appliance manufacturer's instructions and design criteria. These will override the sizing guide below and reference must be made to appliance manufacturer.