Air Conditioning Water System Design

2022-11-28

Air Conditioning Water System Design

air conditioning water system

1. Design of condensate system

The condensed water generated in the operation of fan coil units, integral air conditioners, combined air conditioning units, etc., must be discharged in a timely manner. The design of condensate discharge pipe adopts open, non-full flow artesian system. The discharge method adopts zoning discharge, which is generally discharged into the floor drain of the regional center toilet, so that the drainage pipe is short and not easy to leak.

★ Along the direction of the water flow, the slope of the horizontal pipe should be no less than 3 ‰, and no water is allowed.

★ When the condensate pan is located in the negative pressure section of the unit, the outlet of the condensate pan must be set with a water seal. The height of the water seal should be about 50% larger than the negative pressure (equivalent to the height of the water column) at the condensation pan. The outlet of the water seal should be communicated with the atmosphere.

★ Condensate pipes should be made of PVC plastic pipes for anti-condensation heat preservation and air isolation.

★ The top of the condensate riser should be designed to vent air to the atmosphere.

★ When designing and arranging condensate lines, the possibility of regular flushing must be carefully considered and the necessary facilities shall be designed and arranged.

★ The nominal diameter DN(mm) of the condensate pipe shall be determined according to the flow rate of the condensate.

In general, about 0.4kg condensate water is generated for every 1KW cooling load every 1h. In the case of high latent heat load, each 1KW cooling load generates about 0.8kg condensate water every 1h. Usually, the nominal diameter of the condensate pipe is DN20mm.

2. Selection of electronic water treatment instrument and filter

Electronic water treatment instruments and water filters used in air-conditioning water systems are generally selected according to the pipe diameter of the pipe section where the equipment is located.

The cooling water system is an open system, and an electronic water treatment device must be used. The chilled water system is a closed system, and the requirements are not so strict. An electronic water treatment device can be installed in the chilled water system pipeline or the expansion tank inlet pipeline.

3. Selection of automatic water softening device

When the water quality of the project location is relatively hard or the system is large, the circulating water and supplementary water of the system should preferably be softened water. The air conditioning system must be equipped with a water softening device, and a fully automatic water softening device is generally used.

The selection of automatic water softening device is generally selected according to the water replenishment amount of the system. The water replenishment device can be selected according to the actual situation (small device, long system water replenishment time; large device, short system water replenishment time).

4. Selection of expansion tank

The expansion tank is generally selected according to 2~3% of the total water capacity of the chilled water system pipeline. Generally, the volume of the expansion tank of the air-conditioning water system of a building with an area of about 10,000 square meters is 2 to 4 cubic meters.

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