Replacing Central Air Conditioner with Split Air Conditioner 1

[powering2002]

Dear all

My office consists of 4 floors. Originally from the contractor, we use Central Air Conditioner System to cool the rooms and the corridor. But, instead of using Central Air Conditioner, we also install split AC in most of the rooms in our office (80 % of Total Rooms approximately). We install the Split AC because we think that if there were a trouble in Central System, all of the rooms would be hot (if we don't install Split System as backup). We would feel discomfort.
But, now actually The Two AC System (Central and Split Systems) work together. We think that this is inefficient. So we plan to Turn OFF (shut down) The Central Air Conditioner. We Will Install the additional Split AC in the rooms hasn't installed Split AC System. We will also install Floor Standing AC Units to cool the reception room and the corridor.

So my questions are:
1. Is Our Action (Shutting Down Central AC and Install Additional Split AC) CORRECT/EFFICIENT?
2. If Our Action Plan is incorrect, could you give us some suggestions to make our AC System Efficient?

Thanks for your attention

 

[Drazen]

You did not provide us with data on which central air conditioning system you are using, but when you already invested in redundant system, it is hard to talk about efficiency.

Redundant systems are normally used in critical applications like nuclear plants, laboratories, some areas of hospital. For more ordinary applications they can hardly be justified. That is more issue of maintenance organization.

 

[MintJulep]

I suggest that you apply engineering analysis to the situation rather than guessing, which is what it appears you have done to date.

With the information that you have provided it is impossible for anyone here to give you any meaningful guidance.

 

[Compositepro]

A split system alone does not provide outside air ventilation.

 

[urgross]

Sounds like you may have a good setup for a DOAS, at least as one alternative. I would suggest hiring a mechanical engineer or energy consultant, have them compare a 20-year life cycle cost analysis of a baseline system, the existing ducted system, a DOAS, and any other alternative you would like, as long as they meet code (such as proper ventilation air).

 

[sprinkler1000]

Having a Split unit per office as a backup is not a sound idea.

If the central hvac system is well designed, have it repaired as soon as posible when broken.

As other said, with Split per offices you dont provide outside air as easy as through a central air handler.

So, my opinión is go the other way around and keep the central system.

 

[ChasBean1]

Compositepro is correct; ventilating would be your primary dilemma. My question is why do you feel the need to have redundant systems for offices?