Commercial HVAC pumps provide the energy necessary to move fluids used for heating and cooling through the various types of equipment and piping that make up a commercial HVAC system. Choosing the right commercial HVAC pumps for an application affects energy efficiency, operating costs, and the system’s dependability and lifespan. Learning about how different commercial HVAC pumps operate within these commercial systems will help those charged with the heating and cooling buildings and facilities understand why having a reputable distributor to work with when designing and installing a commercial HVAC system is critical.
Commercial HVAC pumps are installed in systems that are either closed-loop or open-loop. Closed-loop systems are, as the name suggests, designed to have their components and the amount of water used sealed or closed in. Open-loop systems are designed to be open to the air.
Closed-loop systems recirculate water through an air-handling coil to heat or cool the air as it enters. Some designs using air handlers first expose air to a chilled loop of water as it enters the system, which lowers the air’s humidity. This cool, dry air then goes through a heated loop of water to moderate the air temperature before circulating throughout the building. Water also acts as a condenser in other applications, such as remote heat pump installations.
These commercial HVAC systems offer better control and greater energy efficiency than open-loop systems. In closed-loop systems, a controller compares air temperature once it leaves the coil, adjusting the valve until the desired temperature is reached. Selection of HVAC pumps in closed-loop systems must factor in pressure losses due to equipment coils, fittings like tees and elbows, minimum system pressure, net positive suction head, piping length and valves, and other accessories.
While open-loop systems are occasionally used for commercial HVAC systems, they are less common. Pressure loss and static elevation are additional factors to consider when selecting a pump for these systems.
Many kinds of commercial HVAC pumps are used in various commercial systems for heating and cooling buildings. These include cold and hot water circulators for chilled water systems, cooling towers, end-suction pumps, split-case pumps, sump pumps, vertical in-line pumps, vertical multi-stage pumps, and VFD constant-pressure systems.
A chilled water system is a closed-loop system where cold water is pushed throughout a building, cooling the air. As the water travels, it warms. This warm water returns to the chiller to be cooled and dispersed throughout the building once again. A cold-water circulator pump sends the cold water continuously throughout the building. The hot-water circulator pump comes into play to maintain efficiency but not letting the cold water get too cold.
Cooling towers are specialized heat exchangers that cool water by directly mixing it with air. As water evaporates, its temperature drops while circulating through the cooling tower. HVAC pumps move heated water from air-conditioning condensers or industrial processes through pipes to the tower. At the top, nozzles spray water into reservoirs, or "fill," maximizing water's surface area exposed to air. This water flows through the tower, where an electric fan draws air to cool it. The cooled water is then pumped back to condensers or equipment to absorb heat and is returned to the cooling tower to repeat the cycle.
A type of centrifugal pump, the end-suction pump is used in HVAC systems to circulate water or other fluids in a commercial HVAC system. They are often used in smaller systems with lower flow requirements. They have a casing that intakes water from a horizontal end. The water passes through the pump being redirected 90 degrees using the impeller’s centrifugal force. It is then expelled from the top of the pump. Single-stage pumps may be flexible-coupled or close-coupled.
Split-case HVAC pumps are versatile, allowing horizontal or vertical suction and discharge. While double suction is preferred to reduce hydraulic imbalances, these pumps are available in single or double-suction types. Some split-case pumps support multistage functioning with multiple impellers and are best positioned horizontally for HVAC use. Designed with two chambers on a horizontal plane, they handle higher flow rates efficiently. Split-case HVAC pumps are economical, energy-efficient, ideal for larger systems, and operate quietly.
Sump pumps, primarily used to prevent water damage, may seem unrelated to HVAC systems, but they have supportive roles. They help regulate groundwater seepage in basements, protecting HVAC equipment. Additionally, they prevent overflow from condensation during air conditioning and dehumidifying processes. This deters the growth of mold and mildew which can negatively affect indoor air quality.
Vertical in-line HVAC pumps are closely coupled and can be used for double or single suction. Generally, the piping system supports these HVAC pumps while the pump and motor are attached to the casing, reducing their footprint. However, larger versions of vertical in-line pumps are sometimes mounted on the floor, for which unique bases are often installed to reduce vibratory action from the pump’s moving parts.
These pumps provide greater efficiency and resist chemicals better than other HVAC pumps while exceeding DOE standards.
Vertical multi-stage HVAC pumps, with motors on top, save space compared to horizontal pumps. They're ideal for low flow rates and high heads, handling corrosive fluids, and exposure to high temperatures. These pumps extend the system lifespan, cut costs, and reduce downtime, offering energy savings by varying flow rates and pressure. Multiple impellers, shaped like curved blades, are stacked in series on a shared shaft tailored to application pressure needs.
Depending on the climate, HVAC pumps and systems typically operate at peak load only briefly each year. Variable-frequency drives (VFDs) regulate electricity usage in HVAC systems, supplying sufficient electricity to reduce energy consumption. They also enhance energy efficiency by adjusting motor speeds for smoother operation. Other benefits of VFD constant pressure systems include eliminating water hammers in plumbing systems and improving performance with advanced monitoring. Beyond efficiency gains, VFDs extend the lifespan of motor windings and HVAC components by reducing wear and minimizing current draw during startup.
As the largest and oldest distributor of pumps from Maine to New Jersey, Hayes Pump delivers, fits, inspects, and repairs HVAC pumps of all types. These include circulators for chilled water systems, cooling towers, end-suction pumps, split-case pumps, sump pumps, vertical in-line pumps, vertical multi-stage pumps, and VFD pressure systems. Hayes also builds and installs customized HVAC pumps and systems for commercial and industrial facilities.
Hayes Pump distributes commercial HVAC pumps and products from manufacturers that include:
Hayes Pump engineers can design and engineer customized commercial HVAC pumps and systems. We also offer training for HVAC pump operators and maintenance plans for their facilities. To learn more about the HVAC pumps, components, and services we offer, contact the HVAC pump experts at Hayes Pump today.