Understanding the major factors when sizing a cooling system is crucial to obtaining the right product fit.
How Much Cooling Capacity Do You Need?
The most important factor in choosing a cooling system is to determine the amount of heat rejection into the cooling loop. An undersized chiller has the potential to create issues such as:
- The chiller will not provide fluid at the desired temperature.
- The system being cooled suffers in performance or experiences a catastrophic failure.
- Overtemperature alarms are triggered, potentially shutting down the system and process.
What Cooling Fluid Temperature Does Your Process Require?
The setpoint temperature will affect the cooling capacity of a chiller. Decreasing the temperature will put more load on the refrigeration circulating system in water chiller, and vice versa for increasing. There is a direct relationship between the temperature at which you have set the chiller and its total cooling capacity. Therefore, it is important to review the chiller’s performance.
In What Environment Will the Chiller be Operating?
Ambient Temperature: An air-cooled chiller has ability to dissipate heat is affected by the ambient temperature. This is because the refrigeration system uses the ambient air/refrigerant temperature gradient to induce heat transfer for the condensation process.
A rising ambient air temperature decreases the temperature differential (ΔT) and, subsequently, reduces the total heat transfer. An example of the decrease in performance for a 86°F (30 °C) ambient environment as opposed to 68°F (20 °C). Typically, this is a 2 to 3 percent cooling capacity decrease for every 1.8°F (1 °C) increase in the ambient temperature of the chiller’s operating environment.
What Type of Process Fluid Will Be Used?
There are two main concerns when considering fluids: performance and compatibility.
Performance: The performance of a fluid is based upon its properties at a given temperature. Relevant parameters are specific heat, viscosity and freezing/ boiling points. There is a direct relationship between specific heat and cooling capacity.
Compatibility: The potential for corrosion and the early degradation of seals are common failure modes for incorrectly sized systems. Materials of construction and fluids should be compared prior to use.
Most systems will detail the pressure and flow requirements. When specifying the necessary heat load removal as part of the design, it is important to account for all hoses, fittings, connections and elevation changes integral to the system. These ancillary features can significantly increase pressure requirements when not sized appropriately.
What are the Flow and Pressure Requirements of the Process Loop?
Pump life is of primary concern when configuring an industrial cooling system, but the pressure loss across the system and necessary flow rate first must be satisfied by the pump choice.
In summary, adding these five considerations to your technical toolbox will help in determining the optimal industrial cooling system for your application.
If you want to know more about water chiller selection, please contact us.