Assuming there is space in each suite to install a water loop heat pump PTAC unit on an outside wall.
The new PTACs can be ducted readily to the electrical heating locations.
There is a suitable spot for a boiler and evaporative cooler (normally in a penthouse).
Suites are heated by electric baseboard heaters. Electric resistance heating is a very expensive way to heating a building.
Most of the time, heat pumps are much more efficient than electric resistance heaters. It is recommended that the electric heaters be replaced with water-loop heat pumps and a central boiler plant. The new heat pumps would be installed at an outside corner of each suite and ducted to the current baseboard locations. Heat pumps will use the water loop as a heat source/sink. Additional heat will be added to the loop as needed by a central boiler. Loop cooling will be achieved through an evaporative cooler.
Every suite will gain individual air conditioning.
Replace electric resistance heating units with equipment having the lowest practical energy cost.
Because of the low loop temperature, this is a good opportunity for a condensing boiler.
Issues and Concerns
This retrofit puts more maintainable equipment (a refrigeration compressor and a fan) in each suite.
Most savings on the heating side are based on fuel substitution (boiler plant fuel source rather than electric heat).
Allow for smart water loop controller.