I have a high bay manufacturing facility with two100% OSA, CV, low cfm but high
air velocity heating only units. These are intended for comfort heating.

The building also has one 100% OSA, CV make-up air (MUA) unit, with a gas
furnace. The MUA is only used when one or more roll-up doors are open with
trucks inside and unloading. This blows the diesel fumes out of the building.
The MUA has almost 3x the air volume capacity as the two comfort heating units
combined.

When I model the proposed design, with just the two units intended for comfort
heating, I end up with almost 700 unmet heating hours. I add the capacity for
the MUA unit and schedule it for the purpose of comfort heating, and my unmet
hours go down to less than 10.

Also in 90.1, App G, if unmet load hours exceed 300, heating capacity can be
added incrementally until unmet load hours are reduced to below 300.

So would it be fair to not include the MUA unit for heating, but simply add one
or two more of the comfort heating units to get the unmet hours down? It seems
like it may be over-kill to include the MUA unit for the purpose of comfort
heating.

Any guidance would be appreciated.

Thank you,
Pete