Help New Unit Freezstats? Location

[CHAMBERS87]

Have not been in the hospital industry for long, and have come across a design just implemented for a special chem Lab.
Roof (Top Outdoor) Supply Fan with a 100% OA, a preheat Coil, CC at unit (no return), 3 separate exh fans.
Individual Zone Reheats in space.

Recommendations on failsafe freeze protection. It is not overly big unit, but would like more then one freezsstat due to in one fails, would have a back up?

My question is does anyone have come across a similiar setup and if so any suggestions. Pro/Cons

1) Two manual Freezstats? Reset manually at unit? Or relocate them.
2) Series or Parellel
3) Would it be better to have them one down stream of the other or direct parellel from each other?
4) Should they both be set at 36 or 38F?

There is a control rm nearby, and I have noticed some manual resets are in ceilings. Just want to make sure the unit is check too.


Thank you and apprectiate your help so much. Difficult decision.

[beenthere]

Removed your other thread, Please don't make duplicate threads, thank you.

[CHAMBERS87]

Ok, new to this. ty