Recall again, cooling tower makeup water = evaporation loss + drift loss + blowdown. It takes years of experience to be able to quickly select an HVAC system type, size the HVAC system and cost the HVAC system, with limited information. Let say we have cooling tower with the following data: When cycle of concentration below 3 cycles, quantity of water to be discharged will be large. COC is best described as ratio of chloride content in circulation water and in makeup water.īlowdown = /(COC – 1)Ĭycle of concentration is normally 3-4 cycles. The requirement of blowdown is related with cycle of concentration (COC). Drift loss in cooling tower is a function of drift eliminator design.ĭrift loss = 0.02% water supply Blowdownīlowdown is a portion of circulating water that is discharged in order to lower solids concentration due to evaporative cooling. Drift Lossĭrift is entrained water in the tower discharge vapor. The actual evaporation rate is a function of season and climate. T 1 – T 2 = inlet water temperature minus outlet water temperature ( oF)Ġ.00085 is evaporation constant (rule of thumb). Evaporation LossĮvaporation loss is loss of water due to evaporation. Let’s take a look one by one how to calculate each component.

Total cooling water makeup water requirement = evaporation loss + drift loss + blow down. There are aspect that contribute to calculation of cooling tower makeup water. with practical information and comprehensive calculations the way he can conclude a work without. Cooling tower must be made up because the water level decrease by the time during operation. Factors Affecting Cooling Tower Performance Capacity.

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