In our NJ coop (not condo, we have heating/cooling units (essentially fans and fins) beneath each window in each apartment supplied through a water loop (hot or cold) depending on the season via our central heating and cooling plants.

As part of the maintenance, our staff cleans the units, cleans the condensate pipe, replaces filters and performs any necessary maintenance, e.g. fan replacement. This is baked into the monthly maintenance each unit pays which in turn is based on the number of shares. Thus, our costs are based and bundled on a shares per unit basis, regardless of the number of service calls or the number of units in the apartment.

When we convert to condo as we expect we shall, we will continue the same maintenance program.

From my brief reading of the dialogue herein, your building is engaging an outside contractor rather than employ in house staff as we do to perform the tasks above. Perhaps there is no in house staff available.

Using your $352 / unit times our 500 units, I can say that our in house costs are significantly less.