Position of bathroom vent.

[colshaws]

Hi all,
I have been asked to install an inline bathroom fan to be vented through the gable end wall, the gas boiler already vents through this wall about 3 metres away. Does anyone know the regs (if any) regarding the position of the bathroom extractor fan vent in relation to the boiler vent.
Many thanks

 

[MarkieSparkie]

This is not quite as simple as previous posts have suggested, it depends on whether the gas appliance is of the Natural Draught Balance Flue (NDBF) type (older style boilers) or Fanned Draught Balanced Flue type (modern boilers).

Building Regulations, Part J, Combustion Appliances and Fuel Storage systems.
For NDBF systems with Fan Vent vertically above Flue:
Appliance rated net heat I/P 0-7kW ... 300mm separation
Appliance rated net heat I/P 7-14kW ... 600mm separation
Appliance rated net heat I/P 14 -32kW ... 1500 mm separation
Appliance rated net heat I/P >32kW ... 2000mm separation
For NDBF systems with Fan Vent vertically below Flue:
Appliance rated net heat I/P 0-32kW ... 300mm separation
Appliance rated net heat I/P >32kW ... 600mm separation
For NDBF systems with Fan Vent horizontally left or right of Flue
Appliance rated net heat I/P 0-7kW ... 300mm separation
Appliance rated net heat I/P 7-14kW ... 400mm separation
Appliance rated net heat I/P >14kW ... 600 mm separation

For FDBF systems:
300mm separation in all directions

 

[colshaws]

Markie,
You have made me study the chart , you have stated

For FDBF systems:
300mm separation in all directions

I read the table differently, in column M VERTICALLY FROM A TERMINAL ON THE SAME WALL it states 1500mm( that would make my original 1200mm wrong) , I am assuming a terminal meaning another vent or does it mean another gas flue.

 

[Marvo]

Is the gas boiler in the same room you're looking to install the extract fan?

If it is and you pull a negative pressure in that room it could become a health hazard. I would just caution that you test the gas appliance for 'front fluing' when the fan is running.

 

[colshaws]

No the boiler is in a seperate room .