Ventilation for multiple appliances in the same room?

wild nomad · Apr 8, 2015

Hi there,

Im about to take my ACS and need something clearing up. I was taught that if you have 2 or more appliances of the same category in a room (e.g. Open flued boiler & a radiant gas fire) then adventitious air is not taken into account. However, reading other books and online literature seem to suggest that you do take into account adventitious with this particular scenario.

Can anyone provide some clarity?

Thanks in advance 🙂

Ryanmuz01 · Apr 8, 2015

I was told on my ACS Last year that adventitious air should NOT be taken into account.

macka09 · Apr 8, 2015

Yes u do

wild nomad · Apr 9, 2015

Ryanmuz01 said:
I was told on my ACS Last year that adventitious air should NOT be taken into account.

Could I ask you where you did your ACS? Might be the same one as me in Dartford.

kirkgas · Apr 9, 2015

Could I ask where you did it too, I need to make sure I don't go there for mine, IF that's what you were taught, however is it possible that's what you think you heard rather than what you were told?

kirkgas · Apr 9, 2015

Adventitious air is taken into account, BUT only once, as its per room not per appliance, so if you have a 27kw boiler only you take 27-7x5= 100cm2, but if you have two 27kw boilers in the room the vent isn't 200cm2, you add all HI up then -7x5, (27+27-7x5=235cm2)

Dotty · Apr 9, 2015

And we'll end it there. While we want to help you with your training as much as we can we won't do it in open forum.

Get your post counts up to 100+ and apply to join the plumbers arms.