HVAC system of mix used building (apartment, office tower shopping mall are integrated in one location). What should the scheme be?

i prefer to use chilled water system for towers with an energy meter for the apartments 

you may use chilled water system for the office and the shopping mall area only then you may use DX system for the apartment this will be easier to pay the electric bills for DX system i prefer using VRV (one outdoor unit with multi indoor units)

This is some thing very common now a days and it is handled by chilled water system and centrlized system. The billing is done by energy meters on chilled water pipes for each apartment or office or floor so the billing can be done and recorder easily

VRV can also be used but not for very high rise buildings and as i heard these VRV are not suitable for long runs

as per leed certification it  falls under building design and construction (BD+C) the most common method of hvac that can be employed will be chilled water system with chiller and in case there exist a district cooling than we can employ heat exchanges and in order to monitor the chilled water usage the each apartment,shops,and offices can be using BTU meter to monitor the usage and in case of public area like corridors,stores and lift lobby the billing can fall under the owner or client with time set thermostat that can operate during the time of presence of workers usually 8 hours is essential .

HVAC is a widely used air conditioning mechanism used for cooling larger areas  which is more economical than traditional AC's.

In the system ,water (the cooling medium ) is chilled in the chillers and are  transmitted to Air  Handler Units ( AHU) where the heat from the outer air is taken away be the chilled water flowing through cooling coils ans sucked by  the blower.

The cold and fresh air is then thrown at all outlets of ducts.

To maintain the temperature at the required area we can use a Variable Frequency  Drive ( VFD) which not only save the electrical consumption , but also reduces the wear and tear of motor and performance monitoring of it.

The preferred system for this type of application is Central Chilled Water System with Primary, Secondary and Tartary pumps. Chillers should be more than 1000 RT capacity, water cooled system. All three pumping loops should work independently of ther. Primary and Secondary Pumps will be constant speed where as ternary pump will be variable speed to be installed in main pump room of every building, its speed will be keep on changing depend on the demand. In chiller side chilled water flow will remain constant and the capacity will modulate depend on load. Thermal storage tank may be use.