Omar,

For parking deck fans, I have used a direct load on my meters.

I am not sure that the ASHRAE fan allowances were intended to account for fans that do not serve enclosed spaces. Therefore, I've used the same peak power in my baseline and proposed models.

The key variable is the schedule. ASHRAE 90.1-07 User Manual recommends using a schedule "based on likely use."

When installing controls that are not code-required (eg CO monitoring), I would argue that there should be fan power reductions over scheduled on/off and over full out use.

I believe this has been addressed in past posts to the list; I think the recommendation was to use "likely statistical schedules" of use, though I don't recall what these actually were?

The main trouble, in my mind, is I'm not sure we can argue that 100% on all the time control is a reasonable "baseline" for parking garage fans.

Disclosure: To date, I haven't submitted this approach to the GBCI reviewers.

Aaron Dahlstrom , PE, LEED(r) AP