Professionals have been looking for a low-cost water side variable flow (VWV) system solution for small water systems similar to refrigerant variable flow (VRV), adjustable differential pressure bypass valve is a good solution to this problem, but also reduce the initial investment and operating costs of equipment, improve the stability of the host, can be comparable to the VRV system.

User profile

▶ Household central air conditioning (air-cooled heat pump water/ground source heat pump) is mainly used in the air conditioning of family homes (villas and apartments), and these family homes have a low coefficient of simultaneous use (the living room is used during the day, and the room is used at night).

▶ Household hosts hope that the water flow through the host is stable and unchanged, only in this way can the work of the host be reliable and stable operation, but if the end of the electric three-way valve is installed, the temperature to the end of the fan coil still has water through.

▶ The host is selected according to the load accumulation of the existing room, resulting in no energy saving when part of the load is loaded, and the host is frequently started and stopped.

Disadvantages of existing household main water system

▶ The selection of the host did not consider the coefficient of use at the same time, resulting in a large horse trolley, the host can only adjust the cooling capacity through frequent start and stop, the host can not operate normally, in serious cases, the temperature of the host may be too low during the shortest running time, resulting in the heat exchanger freezing.

▶ In order to consider the constant flow of the host, a three-way valve is usually installed in the end fan coil, but the three-way valve has no way to transfer the water flow between the ends, and the air conditioning effect of the user's room has nothing to do with the number of air conditioners used in the room.

The indoor central air conditioning adopts the advantage of differential bypass

▶ When selecting the household host, the most suitable host is selected according to the use of the user, considering the simultaneous use coefficient, so that the host can be reasonably matched with the load, ensuring the operation energy efficiency and operation stability of the host, and reducing the host capacity and the investment of the buffer water tank (increasing the system water capacity, extending the host opening and stopping time). The entire air conditioning system also operates more energy-efficient.

▶ The pressure difference bypass control is adopted in the main water pipe, and the electric two-way valve is installed in the end fan coil. If one electric two-way valve is closed, the flow will be transferred to another open end, that is, the energy can be transferred to each other, and the effect of more open fan coil will be better. This VWV (variable water) system is similar to the VRV (variable refrigerant flow) system of the refrigerant.

▶ The pressure differential bypass valve with vertical scale pressure adjustment indication can make the user very convenient to set the bypass pressure differential according to the actual situation of the project, which completely solves the expensive pressure differential bypass control products of small systems, and makes it possible for the popularity of pressure differential bypass control in small systems. The innovative product design provides convenience for on-site installation and commissioning.

Application of differential bypass energy saving solution

▶ This solution has been launched for four years. Since the air conditioning dealers were worried that the host cooling capacity configured according to this solution was too small, it may be complained by customers. After communication with customers, it has now become a popular solution for users and a selling point for air conditioning dealers, as well as a low-cost and reliable solution for VWV.