Discover how chilled water pumps work, why they matter, and why only professionals should select and install them.
- Chilled water pumps are essential components of HVAC systems
- The pump helps move fluid and keep air cool
- There are multiple chilled water pump configurations
- Selecting the right pump and setting it up properly is important
Commercial sites nationwide need their chiller systems to make indoor conditions comfortable. These systems can be either water-cooled or air-cooled. Our focus is chilled water-cooling systems, which would be useless without chilled water pumps. Here’s our guide to choosing the coolest configuration!
How a chilled water pump works
These pumps move fluid through chilled water-cooling systems and distribute the cooled liquid to the building’s fan coil units or air handling units. This is most commonly achieved using angled fan blades generating centrifugal force, which “impels” liquid to be drawn toward them. This is why these fans are aptly called impellers.
Pumped, chilled water then absorbs heat as it moves through the HVACs pipes. From there, the heat is directly transferred to the air outside the building or into condenser water, which is usually housed in cooling towers on top of the building.
When is a chilled water-cooling system needed?
Chilled water pumps are essential in any building that houses people, equipment, and other sources of heat. Commercial environments can generate enormous heat caused by:
- Multiple people
- Energy-burning items like computers and lighting
- Windows permitting and magnifying sunlight
- Convection as warm air rises from ground level
This trapped, immobilized heat can quickly start affecting the health of everyone indoors unless there is a sufficiently strong chilled water pump to help the HVAC disperse it. Our earlier blog spotlighted the hazards of an overly hot commercial environment, which can lead to many adverse outcomes, including dehydration, nausea, or heat stroke.
There are no laws requiring you to have an HVAC system on your commercial site, but no business wants their employees, visitors, and equipment to become overheated. We recommend taking other heat management steps depending on your business model, like keeping computer rooms cool and monitoring data center temperatures.
The various chilled water pump configurations
Let’s cover some key terms first. GPM (sometimes referred to as the flow rate) stands for gallons per minute and indicates the volume of water that can be pumped around a system in that time. This relates to a pump’s feet of head rating, which shows the altitude to which the water must be pumped to meet the required GPM.
PSI stands for pounds per square inch of pressure. The general rule is that the higher the PSI, the lower the GPM/flow rate, and vice versa. Conversely, the feet of head and PSI always match, with a higher head creating a higher PSI. Now, let’s cover the various pump types:
This design is usually used in larger HVAC systems running in the thousands of GPM. They may need to be fitted with a fixed inertia base to keep them steady and reduce vibration, which could interfere with the pump’s function.
End-suction horizontally draws incoming water and discharges it either perpendicularly or vertically away from the direction of suction. These pumps can be mounted in either a close or flexibly coupled configuration. Close coupling requires less space and fixes the pump securely into the motor shaft – an advantage over the flexible method, which can cause the pump to become misaligned more easily.
- Vertical in-line
This is another close-coupled configuration ideal for limited space installations and, like end-suction designs, can handle thousands of GPM with head ratings up to hundreds of feet. The larger this type gets, the more likely they are to require an inertia base.
Vertical in-lines can be either single or double suction, meaning water can be drawn into the pump from one or two directions. Double suction pumps are usually the more hydraulically balanced of the two, which helps limit flow issues.
These pumps work at the lower end of the capacity and pressure scales, making them better suited to smaller commercial sites. Circulating pumps can be installed horizontally or vertically directly into the piping system.
These flexibly coupled pumps are the easiest for professionals to access and repair. They can be installed vertically or horizontally and supply single or double suction. They can also have more than one impeller, which helps increase their feet of head capacity. Split-case pumps are capable of handling hundreds of PSI and feet of head and thousands of GPM.
Finding the right type and size of pump for your commercial site is only the first step. You really want a pump that can handle more than you need.
Why chilled water pumps need extra punch
You can never know how many people will be in a commercial building at one time, nor how much heat-producing equipment they’ll use. They certainly can’t control the weather, which can see a sudden hot spike or increased wind flow across apertures and cause indoor heat to rise.
Therefore, it’s better to have a chiller pump that can handle demands higher than your site’s minimum predictable levels of occupancy and energy use. Don’t sweat those numbers. Working with professionals will help you understand your site’s HVAC load. They can then confidently calculate the required PSI and the minimum and maximum GPM.
This makes it simple to recommend the right chilled water pump (or possibly pumps) that will work best in the building. Equally importantly, experienced electricians can help commercial sites estimate how expensive running their HVAC system will be over time using certain types of chiller pumps.
Contact the power pros at UES for pump advice
Universal Electrical Services has decades of experience helping customers throughout Florida create the safest, most efficient electrical environments in commercial sites across seventeen industries. Visit our contact page to ask any chiller system or HVAC questions and arrange a free service quote.