Excess heat in HVAC systems can cause downtime, equipment damage, inefficiency, and, consequently, lower profit margins. Industrial chillers help keep HVAC systems running smoothly and buildings cool. With chillers, you can remove exchange heat and keep the process at optimum performance, even when temperatures are high.
That’s why chillers have become a necessity in many industries. They play an important role in the pharmaceutical plants, breweries, hotels as well as meat and poultry processing. Being an integral part of any HVAC system, they provide clean and fresh air to hospitals, keep machines running consistently, and help deep freeze food products until it goes to markets.
So if you’re looking for a chiller for your business, the first thing you’ll need to decide is whether your system is compatible with an air-cooled chiller or a water-cooled chiller. They both have their advantages and disadvantages. Hence, your selection between the two will depend on the needs of your operation including the area, power consumption, local regulations limiting power and water use, or sustainability priorities.
To assist in your research, we have noted down everything you need to know about the air-cooled and water-cooled chillers.
Used in both commercial and personal facilities, Air-cooled chillers cool fluids, exchange heat and dehumidify the air. They actively absorb heat from the processed water and then transfer this heat into the air around the chiller unit.
In this process, heat is absorbed from the chilled water circulating through the evaporator. Then, the compressor pumps the refrigerant vapour to the condenser, thus increasing temperature and pressure. To complete the cycle, the refrigerant flows over the chilled water coils and absorbs more heat.
Air-cooled chillers were mostly popular in areas where additional heat discharge is not an issue but instead works as a benefit. They are also compact and highly efficient heat exchangers, which make them ideal for supplemental, temporary applications. But now they are in a wide variety of settings including hotels, corporate events, restaurants, large-scale construction, industrial and manufacturing plants, etc.
Used for large installations, water-cooled chillers are connected with a cooling tower and use a water-cooled condenser to remove excess heat. They use recirculating water from a cooling tower to condense the refrigerant. This water absorbs heat from the process and the heated water returns to the chiller.
The processed water works as a medium for heat transfers which is why water-cooled chillers can often operate more efficiently than an air-cooled chiller. They ensure more consistent performance because of the relative independence to fluctuations of the ambient temperature. Even if water-cooled chillers are more efficient than air-cooled chillers, this is only true if you look exclusively at heat exchange.
Let’s take a closer look at the other variables to consider before you make a choice between air-cooled and water-cooled chillers:
Performance: Air-cooled chillers are typically available in compact sizes, ranging from 7.5 to 500 tons. Due to their small size and output, air-cooled towers work only for small areas and facilities. Water-cooled chillers are available from 10 to 4,000 tons with output performance ranging from 35 kW to 14,000 kW. So before choosing your cooling tower, make sure to check for the surface area that needs to be cooled.
Maintenance: Air-cooled chillers do not require cooling towers to operate because they use air to remove excess heat. Water-cooled chillers require cooling towers, which increases maintenance demands such as water treatment, tube cleaning, and tower mechanical maintenance.
To overcome these challenges, systems operators use automated water treatment solutions such as SBR, which prevents fouling, biofouling, reduces downtime, cuts maintenance costs and saves water. While air-cooled towers are easier to maintain, water-cooled chillers are more sustainable and deliver higher cooling capacity with fewer units and a smaller footprint.
Durability: Air-cooled chillers are mostly outdoors and operate at higher condenser pressure while Water-cooled chillers are typically installed indoors. They are less prone to damage and operate at lower condenser fluid pressure. However, they still have a shorter lifespan of 15 to 20 years. But with innovative technology solutions like SBR water treatment and ACCS condenser cleaning system, water-cooled chillers last up to 30 years.
While cost & sustainability remains a priority in choosing any powered equipment, the above factors have to be considered too. While the water-cooled chillers are more energy-efficient, air-cooled chillers have a lower maintenance cost and several other aspects.
Yet, the best choice for the project depends on the decisions criteria that are set by you. So take all factors into consideration to make sure the chiller that ultimately gets specified balances all the objectives over the long term.