Summary:
Variable Air Volume (VAV) air conditioning system is an air conditioning system that adjusts indoor temperature and humidity by changing the air supply volume. It has the advantages of energy conservation and environmental protection, and is increasingly being widely used in the market. However, due to the high complexity of VAV air conditioning system control and the large number of VAV BOX, in order to achieve simple and efficient user metering and billing for VAV air conditioning systems, it is necessary to solve the data exchange between the billing system and BMS coefficients. Zhongke Wancheng independently developed and produced the FMU-VAV variable air volume area manager, which is a professional equipment for VAV air conditioning measurement through data exchange with the BMS system. The FMU-VAV variable air volume area manager can integrate the collected VAV air volume data with the BSH2000 energy comprehensive management system of Zhongke Wancheng into one system for billing and management.

Billing principle
Use the accumulated air volume of each VAV air conditioning unit as the basis for charging. The cooling capacity generated by the AHU air handling units on each floor is used as the cooling capacity for this floor
The total amount of cooling consumed by VAV BOX. According to the proportion of accumulated air consumption of each VAV BOX within the agreed settlement period to the total air volume of the entire floor,
Allocate the cooling capacity generated by the AHU air handling unit on this floor. This can reflect the principle of fairness of using more and paying more, and using less and paying less.

Implementation method
By communicating with the BMS network controller through the Zhongke Wancheng FMU-VAV area manager, the air volume of the VAV BOX on each floor is accumulated in real-time.
Measure the cooling consumption of the AHU by installing a heat and cold meter on the supply and return pipes of the AHU on the floor.
Calculate the price per unit of cooling capacity by measuring the total cooling capacity, total electricity consumption, and total water consumption of the central air conditioning system.
Calculate the cost that each AHU needs to bear based on the unit price of cooling capacity and the cooling consumption of each floor AHU.
Calculate the cost that each VAV BOX needs to bear based on the proportion of air consumed by each VAV BOX to the total air volume of the floor.

System schematic diagram (wired and wireless solutions)