This issue has been confusing to me for a while, according to the calcs below on Meyerfire Prep 2019, it looks that Lumens = cd, I doubt this is correct.

If I search the internet, there are should have a factor, which is the solid angle.

Cd = lumens/ sr

From Wikipedia I found that E is Illuminance which is in lumens/m^2 which is the incident flux on a surface, as in the problem. One lumen per square meter is a Lux.

Are the units on this correct?

Problem 183:  For the final step, “Volumetric Flow Rate of Smoke,” the unit obtained as you show would be ft^3/s.  So, in order to obtain the final answer in CFM, the value in ft^3/s should be multiplied by 60 in order to convert to ft^3/min, or CFM.

Is this valid?