Air conditioning system

The air conditioning system 15, further comprising:

• a first building header for supplying the hot water flow to the first and second changeover boxes;
• a second building header for supplying the cold water flow to the first and second changeover boxes;
• a third building header for receiving the hot water return from the first and second changeover boxes;
• and
• a fourth building header for receiving the cold water return from the first and second changeover boxes,
• wherein each of the first and second changeover boxes is connected to the building headers by separate connections.

A changeover box for controlling flow of hot and cold water in an air conditioning system, the changeover box comprising:

• a first input arranged to receive a hot water flow from a hot water loop of the air conditioning system;
• a first output arranged to provide a hot water return to the hot water loop of the air conditioning system;
• a second input arranged to receive a cold water flow from a cold water loop of the air conditioning system;
• a second output arranged to provide a cold water return to the cold water loop of the air conditioning system;
• a third output arranged to provide flow to a first air to water heat exchanger;
• a third input arranged to receive a return from the first air to water heat exchanger;
• a fourth output arranged to provide flow to a second air to water heat exchanger;
• a fourth input arranged to receive a return from the second air to water heat exchanger;
• a first control valve arranged to be coupled to the first air to water heat exchanger;
• a second control valve coupled to the second air to water heat exchanger;
• a changeover box controller arranged to operate the first and second control valves, and the first and second air to water heat exchangers,
• wherein:
• each of the first control valve and second control valve is arranged to:
• receive the hot water flow in from the hot water loop and the cold water flow from the cold water loop;
• selectively provide the flow from a one of the hot water loop or the cold water loop to the associated air to water heat exchanger;
• receive return from the associated air to water heat exchanger;
• and selectively provide the return from the associated air to water heat exchanger to the return of the one of the hot water loop or the cold water loop;
• the changeover box controller is arranged to connect to a heat exchanger controller of the first air to water heat exchanger via a first communication link;
• and
• the changeover box controller is arranged to connect to a heat exchanger controller of the second air to water heat exchanger via the first communication link and a second communication link between the heat exchanger controller of the first air to water heat exchanger and the heat exchanger controller of the second air to water heat exchanger.