Sep 23, 2017
A buffer tank is a type of pressure vessel for chilled water systems that have insufficient water volume capacity. Chilled water systems with low capacity tend to have issues, including poor temperature control, excessive compressor cycling and other issues.
Chilled water systems are an effective way to cool a large space, such as in a tall building or warehouse. Good insulation, along with a powerful cooling tower, can lower the temperature inside a building more efficiently than a standard air conditioning system. The addition of a buffer tank can, therefore, improve the system’s performance and prevent problems down the line.
Before you decide to install a buffer tank, here is what you should consider first:
Determining if you need a tank in the first place
Not all systems benefit from a buffer tank as some may already have an adequate volume of water in them. Most chiller manufacturers will recommend that the system volume be between 3 to 6 gallons per tonne for normal air conditioning applications. If you need greater control over the temperature, you may want to increase it to up to 10 gallons.
You, therefore, have to calculate the required system volume of the manufacturer, as well as the existing water volume in the system. Generally, the size of the buffer tank is equivalent to the actual system volume subtracted from the required volume. If the required volume exceeds the actual system volume, may need to add a buffer.
Choosing your tank
Once you have figured out your buffer tank’s capacity, you will have to ensure that the insulation thickness matches your requirements. You also have to keep in mind the flow rate of the chiller, the location of the unit, and the tank temperature.
It is important that your buffer tank is compatible with your system. You may need optional accessories, including connectors and additional valves.