Correct chiller installation is the single most important factor in ensuring long-term reliable performance, energy efficiency, and equipment life. A chiller that is incorrectly positioned, improperly piped, or poorly commissioned will underperform, consume excess energy, and require frequent service calls — regardless of build quality.

This guide covers the complete chiller installation procedure for both air-cooled and water-cooled chillers: site preparation, mechanical positioning, piping connections, electrical installation, refrigerant charging, and commissioning. A downloadable checklist is included at the end.

Important: Always refer to the specific installation manual provided with your chiller unit. This guide provides general best-practice procedures applicable to most industrial and commercial chillers. Where the manufacturer’s instructions differ from this guide, always follow the manufacturer’s instructions.

Step 1: Pre-Installation Planning and Site Preparation

Before the chiller arrives on site, complete the following site preparation work. Attempting to install a chiller without completing these steps first is the most common cause of installation delays and rework.

Foundation and Structural Requirements

  • The installation surface — floor, concrete pad, or steel frame — must be level to within 6.4 mm across the entire base of the unit.
  • The surface must be capable of supporting the operating weight of the chiller (not just the shipping weight — the operating weight includes the refrigerant charge and water fill). Consult the chiller’s technical datasheet for the operating weight.
  • For rooftop installations, confirm with a structural engineer that the roof can support the chiller’s operating weight plus dynamic loads from vibration.
  • Install anti-vibration mounts or rubber isolator pads on the foundation before positioning the chiller. These reduce vibration transmission to the building structure and are required for most indoor and rooftop installations.

Clearance Requirements

  • Air-cooled chillers: Minimum clearances around and above the unit are specified in the manufacturer’s installation manual — typically 1.0–1.5 m on sides and 2.0 m above. Never install an air-cooled chiller in a confined space without confirming airflow adequacy. Recirculation of hot discharge air is the most common cause of air-cooled chiller underperformance and high-pressure trips.
  • Water-cooled chillers: Require access space at one end for condenser tube bundle cleaning — allow minimum 1.5× the tube bundle length. Confirm this space is available before finalising the installation location.
  • All sides must have adequate access for routine maintenance: filter cleaning, refrigerant charge checks, oil level checks, and electrical panel access.

Utility Connections — Confirm Before Delivery

  • Electrical supply: correct voltage, frequency, phase, and ampacity confirmed and available at the installation point.
  • Chilled water pipework: sized and routed to the installation point, with isolation valves and service connections planned.
  • For water-cooled chillers: cooling water supply and return pipework from the cooling tower confirmed and routed.
  • Drain connections planned for evaporator and condenser drain points.

Step 2: Mechanical Positioning and Rigging

  • Use the lifting points designated on the unit — never lift a chiller from pipework, fan guards, electrical panels, or other components. Lifting from incorrect points permanently damages the frame and voids warranty.
  • Keep the unit upright at all times during transport and installation. Do not tilt scroll or screw compressor chillers beyond 15° from vertical — compressor oil may migrate into the refrigerant circuit.
  • Once positioned on the anti-vibration mounts, re-check level in both axes. Adjust mounts until level deviation is within 1‰ (1 mm per metre) for modular chillers, or within 6.4 mm total for packaged units.
  • For multiple modular chillers installed in parallel: install a common steel base frame and bolt all units to the base. Ensure the combined unit is level before making pipe connections.
  • Do not remove shipping braces, compressor hold-down bolts, or vibration isolator shipping restraints until the unit is in its final position.

Step 3: Chilled Water and Cooling Water Piping

Piping errors are the second most common cause of chiller problems after improper siting. Follow these requirements carefully.

General Piping Rules

  • All pipework must have independent supports — never allow pipe weight to rest on chiller connections. Stress on chiller connections causes leaks and heat exchanger damage over time.
  • Install flexible vibration-isolating connectors (flexible hose or expansion joints) between the pipework and the chiller connections to prevent vibration transmission.
  • Install isolation valves on both supply and return connections to allow chiller service without draining the entire system.
  • Install Y-type strainers on the inlet of both the chilled water and cooling water circuits, immediately upstream of the chiller connections. Clean these strainers after the first 24 and 72 hours of operation to remove construction debris.
  • Install pressure and temperature gauges on supply and return connections for ongoing performance monitoring.
  • The highest point in the chilled water system must have an automatic air vent valve. The lowest point must have a drain valve.

Chilled Water Circuit

  • The chilled water pump must be located on the inlet pipe to the chiller evaporator — not the outlet. This ensures positive pressure through the evaporator and prevents cavitation.
  • Minimum water flow rate through the evaporator must be maintained at all load conditions. Refer to the chiller datasheet for minimum flow rate. Install a water flow switch that interlocks with the chiller controller — the chiller must not start or operate without confirmed flow.
  • After piping is complete, flush the entire chilled water system before connecting to the chiller. Construction debris in the evaporator causes tube fouling and corrosion damage.
  • After flushing, pressure test the pipework at 1.5× operating pressure before insulating.
  • After the pressure test is passed, insulate all chilled water pipework to prevent heat gain and condensation dripping. Minimum insulation thickness: 25 mm for pipes up to DN50; 40 mm for larger pipes.

Cooling Water Circuit (Water-Cooled Chillers Only)

  • Size the cooling tower to match the chiller’s heat rejection capacity — not the chiller’s cooling capacity. Heat rejection capacity is typically 120–130% of cooling capacity.
  • Install the cooling water pump on the inlet pipe to the chiller condenser.
  • Install a water treatment dosing system on the cooling water circuit. Untreated cooling tower water causes rapid scaling and biological fouling in the condenser, reducing efficiency and causing premature failure.
  • For outdoor cooling towers in cold climates: install freeze protection on the cooling tower basin and pipework, or drain the cooling water circuit when ambient temperatures approach 0°C.

Step 4: Electrical Connections

  • All electrical work must be performed by a qualified licensed electrician in accordance with local electrical codes.
  • Verify the incoming power supply voltage, frequency, and phase sequence before making connections. Incorrect phase sequence causes reverse rotation of compressors and pumps, resulting in immediate damage.
  • Voltage tolerance: The supply voltage must remain within ±10% of the rated voltage under all load conditions. Voltage fluctuation beyond this range requires a voltage stabiliser before the chiller.
  • Use the cable entry point designated on the electrical panel. Do not route cables across moving parts, hot surfaces, or sharp edges.
  • Ensure the earthing (ground) connection is made before energising the unit. All Geson chillers use three-phase five-wire supply: R, S, T (live), N (neutral), G (earth/ground).
  • Install a dedicated isolator switch for the chiller within sight of the unit, lockable in the open position for safe maintenance access.
  • For units with remote controls, Building Management System (BMS) connections, or alarm outputs: connect these low-voltage signal cables separately from power cables to prevent interference. Use shielded cable for BMS/RS-485 connections.
  • Do not modify the factory-wired control circuit. The control circuit is installed and tested at the factory. Modifications void the warranty and may create safety hazards.

Step 5: Pre-Commissioning Checks

Before starting the chiller for the first time, complete all items on this pre-commissioning checklist. A chiller started without completing these checks risks compressor damage, refrigerant leaks, and electrical faults.

  • ☐ Foundation level verified — within 6.4 mm total / 1‰ for modular units
  • ☐ Anti-vibration mounts installed and correctly positioned
  • ☐ All shipping restraints and compressor hold-down bolts removed
  • ☐ Chilled water system flushed, pressure tested, and leak-free
  • ☐ Chilled water pipework insulated
  • ☐ Y-strainers installed on chilled water and cooling water inlets
  • ☐ Water flow switches installed and wired to chiller control panel
  • ☐ Cooling water system filled and vented (water-cooled units)
  • ☐ Cooling tower operational and connected (water-cooled units)
  • ☐ Electrical supply verified: correct voltage, frequency, phase sequence
  • ☐ Earth/ground connection made and verified
  • ☐ All electrical connections tight — no loose terminals
  • ☐ Refrigerant charge verified (factory-charged units: check sight glass)
  • ☐ Compressor oil level verified (where accessible)
  • ☐ Control panel settings reviewed: setpoint temperature, alarm thresholds, time clock
  • ☐ All access panels and covers replaced and secured
  • ☐ BMS/remote monitoring connected and tested (if applicable)

Step 6: First Start-Up and Commissioning

  1. Start the chilled water pump first — confirm flow before starting the chiller. The water flow switch must confirm flow before the chiller controller will allow start.
  2. Start the cooling tower and cooling water pump (water-cooled units) — confirm flow before starting the chiller.
  3. Start the chiller and monitor the following parameters during the first 30 minutes of operation:
    • Chilled water supply and return temperatures — should reach setpoint within 20–40 minutes depending on system volume
    • Suction and discharge pressures — compare to the refrigerant PT chart for the operating conditions
    • Compressor running current — should be within nameplate rating
    • Chilled water flow rate — should match design flow
    • Cooling water flow rate and temperature (water-cooled units)
    • Any alarms or fault indicators on the control panel
  4. Check for refrigerant leaks at all connections, service valves, and brazed joints using an electronic leak detector or UV dye.
  5. Clean Y-strainers after 24 hours and again after 72 hours of initial operation to remove construction debris mobilised by flow.
  6. Record all commissioning data — suction/discharge pressures, temperatures, running currents — in the unit’s commissioning log. This baseline data is essential for future fault diagnosis.

Common Chiller Installation Mistakes to Avoid

Mistake Consequence How to Avoid
Hot air recirculation on air-cooled chiller High-pressure trips, reduced capacity, compressor damage Maintain minimum clearances; check for nearby walls, barriers, or other heat sources
No Y-strainer on chilled water inlet Debris in evaporator — tube fouling, reduced heat transfer, blocked sensors Always install Y-strainer immediately upstream of evaporator inlet
Pipe weight on chiller connections Connection leaks, heat exchanger stress cracking All pipework independently supported; flexible connectors at chiller
Wrong phase sequence on electrical supply Immediate compressor and pump motor damage on first start Verify phase sequence with phase rotation meter before first start
No water flow switch or flow switch bypassed Evaporator freeze-up and tube cracking when pump fails Install and wire flow switch; never bypass for commissioning convenience
Chilled water system not flushed before connection Construction debris damages evaporator tubes within days Flush system completely before connecting to chiller
Insufficient cooling tower capacity High condensing pressure, reduced efficiency, compressor overload Size cooling tower at 120–130% of chiller cooling capacity
Untreated cooling tower water Condenser scaling and fouling — efficiency loss and premature failure Install water treatment system before commissioning

Geson Installation Support

All Geson chillers are factory-tested at full load before delivery, with test records and commissioning data included in the delivery documentation. Each unit ships with a detailed installation manual specific to the model.

Geson’s engineering team provides the following installation support services:

  • Pre-installation review: Submit your site plan and Geson will review clearance requirements, piping layout, and electrical supply before the unit ships.
  • Remote commissioning support: Geson engineers are available by phone and video call during first start-up — response within 30 minutes, solution within 2 hours.
  • On-site commissioning: Available for large or complex installations. Contact Geson for availability and terms.
  • 24/7 technical support: After commissioning, Geson provides ongoing technical support for the life of the unit.

Contact Geson technical support →

Frequently Asked Questions about Chiller Installation

How long does chiller installation take?

A standard packaged air-cooled chiller installation typically takes 2–5 days for a single unit, depending on site conditions and the complexity of the piping and electrical work. Water-cooled chiller installations take longer — typically 5–10 days — due to the additional cooling tower pipework and treatment system. Large multi-chiller central plant installations may take several weeks.

Can I install a chiller myself?

Mechanical positioning and piping work can be carried out by qualified mechanical contractors. Electrical connections must be made by a licensed electrician. Refrigerant handling and commissioning — including checking refrigerant charge and verifying operating pressures — must be performed by a qualified refrigeration technician holding the appropriate certification for the refrigerant type (EPA Section 608 in the US, F-Gas certification in Europe, or equivalent).

What foundation does a chiller need?

The foundation must be level to within 6.4 mm across the unit base, and strong enough to support the chiller’s operating weight (including refrigerant and water). Concrete slabs of minimum 150 mm thickness are typical for ground-level installations. Anti-vibration mounts should always be installed between the chiller base and the foundation to reduce vibration transmission. For rooftop installations, structural engineering assessment is required.

How much clearance does an air-cooled chiller need?

Minimum clearances vary by model — refer to the installation manual for your specific unit. As a general guide: 1.0–1.5 m on sides, 2.0 m above, and 3.0 m in front of the air discharge. The most critical requirement is preventing hot discharge air from recirculating back to the condenser inlets. Even partial recirculation significantly reduces capacity and causes high-pressure trips.

What water quality is required for a chiller?

Chilled water systems should use clean water with appropriate corrosion inhibitors. Cooling water circuits for water-cooled chillers require water treatment to control scale, corrosion, and biological growth (including Legionella). Water pH should be maintained between 7.0 and 9.0. Hardness, conductivity, and inhibitor levels should be tested monthly. Contact a water treatment specialist for a system-specific treatment programme.

Do I need to add refrigerant when installing a Geson chiller?

No. All Geson chillers are factory-charged with refrigerant and pressure-tested before delivery. Under normal circumstances, no refrigerant should be added on site. If the sight glass on the liquid line shows bubbles after 30 minutes of stable operation, this indicates a refrigerant shortage — contact Geson technical support before adding refrigerant, as this may indicate a leak that must be found and repaired first.

What is the minimum water temperature for a chiller?

Standard Geson chillers are designed for chilled water supply temperatures of +5°C minimum for water-only systems. For setpoints below +5°C, a glycol-water mixture is required to prevent evaporator freeze-up. Contact Geson engineering when ordering if your application requires setpoints below +5°C, so the unit can be factory-configured with the appropriate evaporator and glycol concentration.

Related Resources