I'm modeling a 5-story, 99,000 square foot self-storage facility for the
purpose of the energy efficiency tax credit for commercial buildings.

Based on the ASHRAE 90.1 User's Manual, I believe this facility would
fall under System 5 (Packaged VAV with reheat boxes fed from a hot water
loop). However, the spaces themselves are kept at non-standard
conditions. 55 degrees during heating season, 80 degrees during cooling
season. The owners have discovered that 5-ton residential split systems
(with condensing furnaces) are great at being a budget HVAC system that
maintains the space temps.

Is a system with five (5) DX RTUs feeding shutoff VAV boxes with hot
water reheat fed from a central boiler system really the Baseline
building? Seems like overkill, and it seems like there is no way that
it would be more efficient than a couple split systems per floor.

The storage units are all open to each other, so based on App G, it
looks like I just have to model a zone for each exposure and an interior
zone.

Any thoughts? Is this the proper Baseline system?

Thanks!

James Hansen, PE, LEED AP