The Hidden Reason Why Air Cooled Chillers Need Makeup Water

1. The Hidden Reason Why Air Cooled Chillers Need Makeup Water An air cooled chiller is supposed to be… well, air cooled. Every engineer, facility manager, rental technician or procurement lead expects it to run without a water dependency. So the moment someone spots a makeup water connection on a portable air cooled chiller, the first reaction is usually confusion. “Why is there water here at all?” This single detail creates unnecessary debate in meetings, commissioning calls, and field visits. But the explanation is surprisingly simple once you understand how the hydraulic circuit inside the chiller is designed. What follows is a clear breakdown of why the connection exists, why it is essential, and why even scroll chillers fall into the same category.

2. Air Cooled Means “Air Condensed”, Not “Waterless Operation” Air cooled chillers remove heat from refrigerant using ambient air rather than cooling tower water. That part is true and unchanged. The condenser coil stays dry. The fans push air across fins to reject heat. But that’s only one half of the machine. The This loop has: other half is the chilled water loop. • • • • • • Safety valves A built-in or external tank Pumps hoses circuit points Flexible closed vents A hydraulic Air and drain This is the part that still uses water, and it behaves exactly like any other water system in the real world. Water Water Water Water escapes when the system is purged during commissioning. evaporates in during slowly through hoses or vents. fittings. cleaning. leaks spills tiny amounts hose through and reconnection tank When the tank level dips below the minimum threshold, the pump starts pulling air. This causes: • • • • • Chilled water temperature swings Pump Flow Low-pressure Safety cavitation instability alarms cutoffs That is why a makeup water line is installed. It is not an add-on. It is a safeguard that keeps the system running without interruptions.

3. Why Portable Air Cooled Chillers Need Makeup Water Even More Portable They travel between factories, events, commissioning sites, testing bays, and temporary installations. units live a hectic life. They face: • • • • • Occasional spillage during draining or transport Frequent pipe or hose during in from reconnections startup Air pockets Variations load Minor leaks movement Every If the tank runs low while the unit is operating, the chiller can shut down unexpectedly. small loss adds up. Makeup It keeps the hydraulic loop topped up automatically without human intervention. This is especially valuable for rental companies, commissioning teams, and field technicians who deal with time-pressed operations. water prevents this. In short, makeup water is the invisible support system keeping portable air cooled chillers consistent and reliable. What About Scroll Chillers? Do They Need Makeup Water Too? This question appears often, and the answer is straightforward. Scroll chillers also use water-filled chilled water circuits. The compressor type only affects how refrigerant is compressed. It does not change anything about: • • • • Flow dynamics Tank Pump Hydraulic volume behavior stability Scroll chillers lose water for the same reasons:

4. • • • • • Evaporation at the tank Hose release movement startup joints venting Air Minor during leaks in System So yes, scroll chillers need makeup water whenever a water circuit is present. A scroll compressor cannot overcome the physics of water loss. The laws of hydraulics are compressor-agnostic. Why Makeup Water Matters for Performance and Equipment Life A The decline is subtle and often invisible until the alarm goes off. chiller doesn’t immediately fail when water starts dropping. Here’s what happens inside: 1. Air The pump loses pressure, flow becomes turbulent, and the cooling loop turns unstable. 2. Evaporator loading Without consistent water volume and flow, refrigerant doesn’t evaporate uniformly. The efficiency 3. Suction and discharge The compressor experiences irregular loading, which reduces its operating life. 4. Control logic Temperature sensors start receiving noisy readings. The system may short cycle, overshoot, or enters the pump suction fluctuates curve drops. pressures shift struggles undershoot. These A few litres lost from the tank can quietly cut efficiency by several percent. performance losses begin long before any alarm lights up. Makeup water fixes this by maintaining stable volume, steady flow, and predictable evaporator performance. It is not optional. It is a form of ongoing insurance. So Does an Air Cooled Chiller “Use” Water?

5. No. It It only requires enough water inside the loop to run smoothly. does not consume water like an evaporative cooling system. Think You are not “using” coolant; you are compensating for small, inevitable losses. of makeup water like the top-up in a car’s coolant reservoir. The presence of the connection does not contradict the definition of air cooled chillers. It simply acknowledges the real-world behavior of water circuits. Conclusion An air cooled chiller is engineered to reject heat using air, not water. But the chilled water loop inside the machine still operates on a controlled volume of water that must remain stable. Small losses happen naturally through daily operation, and makeup water ensures the loop never drops below the safe limit. Scroll chillers follow the same principle because compressor technology does not change the way hydraulic circuits behave. This misunderstood little connection is not an error or an inconsistency. It is a clever safeguard that keeps air cooled chillers efficient, reliable, and perfectly stable in real- world environments. Want to explore air cooled chillers for your needs? Climaveneta India brings the best of them for you.