Air Conditioning at Office

Typically we use Air Handling Units (AHU) at large offices in India. Recently we are seeing variable Refrigerant Flow (VRF) system being aggressively promoted as something which is low-maintenance, more efficient system. We are planning a 5 floor building of 25000 Square feet each. For comfort air conditioning to our staff we need these VRF system.

I request Design experts /existing users to give their thoughts on below:

How efficient it is compared to traditional AHU (in terms of power savings for say 10000 Sq foot area)

What is its relaibility considering that in India we do not get continous power as there would be frequent failure of GRID power. During these time our stand by generator comes on.

As this is Microprocessor based system, does it possess any built-in protection against over voltage, surge, fluctuations etc.

Thanks