I have been going through the EN12101-6:2005 Standard trying to size a system for a class B fire fighting arrangement (Pressurised Lift, loby and Staircase). I have an issue with the nonclemature, under appendix A.2.2 Estimation of leakage via lift landing doors. it provides the follwing equation:
Qld = 0.83 x ( 1/a1^2 + 1/af^2)^1/2 x Pl^1/2
where af - is the total leakage area between lift well and external air (this is where I have an issue is this refering to the path from the lift to the outside,external to lift?)
where a1 - would be the total leakage area to the protected space.
side note looking at the above equation it appears to be substituting air leakage area in series which adds another question.
Appreciate any assistance and sorry before hand if this is an elementary question.