Basement ventilation

[Scott_D]

Looked at a 70kw open flued boiler in a basement.
The only ventilation available is at high level (ground level outside) with no obvious way of getting the high and low level ventilation needed. The existing vent is big enough to cover both high and low level requirements.
I had thought about ducting down to provide a low level vent, but this would still leave the outside grills in the same space. Not one high and one low.

Anyone have a good solutions?
Or have access to the British standards they would share so I can read more into it BS.664 and BS.5440:2

 

[Rob Sale]

Ducting is the answer, bringing it down to floor level and keep the existing one where it is for the high.

 

[Scott_D]

The only issue is that they would be the same level out side (low level).
They should be one high and one low but its not possible as its the front of the property.

 

[Reg Man]

Ducting your low level ventilation is what is recommended. It does not make any difference if the external vents are in the same position. By ducting you are effectively seperating for high and low vents. Refer to BS6644 commercial boilers 70KW to 2MW 6.9.3.3.1.5

 

[Scott_D]

I will try and get access to BS 6644
Thanks for your input guys

###Just an update, I called gas safe and they confirmed the above information.
I was looking at information where both high and low level vents were ducted down to the basement, in this case the external grills should have the same height difference as the internal grills.