HVAC Pumps: 4 Different Types of Pumps to Consider

Commercial pumps are widely used in many HVAC systems. They provide the pressure required to move water through piping. However, the word “pump” can have several meanings.

When selecting a booster pump for an HVAC system, there are several factors to consider, such as operating expenses, energy costs, system reliability, etc. Also, there are different types of HVAC pumps. So, let’s look at the most common types of pump systems used in HVAC.

 

• Circulator Pumps

Circulator booster pumps are used in low-capacity HVAC systems. They are designed to circulate water through a closed system in a loop between the discharge and suction sides without ever getting exposed to atmospheric pressure. These pumps can also be used in a completely closed system, which requires an expansion tank attached to the pump’s suction line to prevent the piping from becoming overpressurized.

Circulator pumps are most commonly single-stage pumps, and the size is typically under 150 GPM. While small systems are designed to be close coupled to eliminate the need for a mechanical seal, high-flow versions are vertical in-line pumps with mechanical seals.

 

• End Suction

End suction is mostly a single-stage pump with a casing with suction on one side and discharge at the top. It can be either close or flexible coupled. While close-coupled pumps have the impeller directly mounted to the motor shaft, flexible-coupled pumps have the impeller and the motor shaft separated by a coupling.

Usually, end suction pumps up to 4000 GPM of capacity and 150 feet of the head are used in HVAC systems. Close-coupled pumps are preferred as they have the advantage of taking up less floor space. Make sure the pump is installed on a solid base.

 

• Split Case

Like end suction, split case pumps are flexible coupled commercial pumps. With the assembly mounted to a baseplate, the suction and discharge sides are arranged horizontally and are perpendicular to the shaft. They are available in single suction, which means the water enters the impeller from only one side. Some split cases are also double suction, which means the water enters the impeller from both sides.

You can choose double suction pumps over single suction, as they can reduce the risk of hydraulic imbalance. They are also available with multiple impellers for multistage applications and can be horizontal or vertical split cases. The horizontal split case is best for HVAC applications as it is more economical for high-flow applications. Split case HVAC pumps can be used for large capacities up to 6,500 GPM and a head up to 600 feet.

 

• Vertical in-line

Vertical in-line pumps can be either single or double suction. They are close-coupled and are directly mounted on the pump casing. These pumps are typically mounted and supported by the piping system to ensure a small site footprint.

For larger applications, the pump assembly can have a base for floor mounting. You can use inertia bases to reduce vibration from the rotating parts within the pump. Vertical in-line pumps are best for a capacity of up to 25,000 GPM and a head of up to 300 feet.

If you have any questions regarding HVAC pumps or building services pumps, don’t hesitate to contact us.