Hello All,

I have a building where we are performing calcs on a select number of assumed potential critical zones as opposed to every zone. Regarding estimating and over-riding system Ds (percent of total design airflow at conditioned analyzed), is the following an appropriate strategy considering that I don't have access to the mechanical as-builts?

I will study the furniture plan and come up with a VAV zoning plan using engineering judgement. Based off of that VAV zoning plan, I will determine square feet of "exterior" and square feet of "interior". I will then apply common industry practice and assume a 20% minimum CFM setting for interior zones, a 50% minimum CFM setting for "regular" exterior zones, and a 75% minimum CFM setting for exterior zones with multiple exposures and a lot of glass and/or operable windows/doors (infiltration). The appropriate percentages will then be applied to the appropriate square footages and averaged to get a system Ds.

Does this approach seem like it will suffice for the 62MZ requirement as "sufficient information or backup calculations to confirm that the conditions represent the worst case"?

As always, your help is beyond appreciated.