How to Select a Chiller for Ambient Temperatures of 50–55°C

HEAD-POWER – Professional Central Air-Conditioning Manufacturer

Selecting a chiller for a normal commercial building is already an important engineering decision. However, selecting a chiller for a project located in a desert or extremely hot climate requires much more careful consideration.

In many parts of the Middle East and Africa, outdoor summer temperatures can reach 50°C, and in some locations the design temperature may approach 55°C. Under these conditions, a standard air-cooled chiller may not provide the expected cooling capacity or stable operation.

HEAD-POWER supplies central air-conditioning equipment for industrial, commercial and process-cooling applications in high-temperature regions, including Saudi Arabia, the United Arab Emirates, Qatar, Kuwait, Bahrain, Oman, Yemen, Iraq, Jordan, Israel, Palestine, Lebanon, Syria and Iran, as well as Egypt, Libya, Algeria, Tunisia, Morocco, Sudan, South Sudan, Mauritania, Mali, Niger, Chad, Burkina Faso, Nigeria, Ghana, Kenya, Tanzania, Ethiopia, Somalia, Djibouti and other African markets.

The actual design temperature must always be confirmed according to the project location and local engineering requirements. Not every city in these countries has the same outdoor conditions.

Why Does Ambient Temperature Matter?

An air-cooled chiller rejects heat through its condenser coil and condenser fans. As the outdoor temperature increases, the condenser has to work harder to release heat into the surrounding air.

At high ambient temperatures, the chiller may experience:

Lower cooling capacity;

Higher condensing pressure;

Higher compressor discharge temperature;

Increased electrical consumption;

High-pressure alarms;

Condenser fan shutdown;

Compressor safety trips;

Unstable operation;

Shortened component life.

This is why a chiller selected only by its nominal capacity may not be suitable for a project where the actual outdoor temperature reaches 50–55°C.

For example, a chiller marked as 100 kW may deliver 100 kW under standard rating conditions, but the available capacity may be lower at 50°C or 55°C ambient temperature. The final selection must therefore be based on the actual operating condition, not only the model name or catalogue rating.

1. Confirm the Project Location and Design Temperature

The first step is to confirm the exact project location.

The customer should provide:

Country and city;

Project elevation;

Normal summer temperature;

Maximum expected temperature;

Required design ambient temperature;

Whether the chiller will be installed on a roof, beside a building or in an enclosed plant area;

Whether the equipment will be exposed to dust, sand or salty coastal air.

For example, the design condition in Riyadh may be different from that in Jeddah, Dubai, Muscat, Aden, Doha, Cairo or Khartoum. Even within the same country, the required chiller configuration may be different.

For high-temperature projects, the customer should clearly state whether the chiller must operate at:

45°C ambient;

50°C ambient;

52°C ambient;

55°C ambient;

Or another specified design condition.

2. Check the Actual Cooling Capacity at 50–55°C

The most important technical point is the cooling capacity available at the actual design ambient temperature.

The quotation should clearly state the performance basis, including:

Cooling capacity at the required ambient temperature;

Chilled-water entering temperature;

Chilled-water leaving temperature;

Water flow rate;

Compressor input power;

Total running current;

Refrigerant type;

Condensing temperature;

Operating range;

Allowable water pressure;

Sound level, if required.

If the customer requires 200 kW of cooling at 50°C ambient, the manufacturer must select the equipment based on 200 kW at 50°C-not simply offer a nominal 200 kW model rated under standard conditions.

In some cases, a larger nominal chiller may be required to ensure that the required cooling capacity is still available at 50–55°C.

3. Select a High-Ambient or T3 Configuration

For extremely hot regions, the chiller may require a high-ambient or T3 configuration.

Depending on the capacity and application, the configuration may include:

High-temperature compressors;

Larger condenser coils;

Increased condenser surface area;

Copper tube and aluminum fin heat exchangers;

High-temperature condenser fans;

EC condenser fans with suitable control;

Special high-pressure protection;

Enhanced compressor cooling;

High-temperature electrical components;

Optimized refrigerant charge;

Modified control parameters;

Improved heat-rejection capacity;

Stronger ventilation requirements.

The exact design depends on the refrigerant, cooling capacity, water temperatures, power supply and required ambient temperature. It should be confirmed by the manufacturer's engineering team before quotation.

4. Confirm the Chilled-Water Conditions

The chilled-water temperatures and water flow rate have a direct effect on the chiller's cooling capacity and efficiency.

The following information should be confirmed:

Chilled-water entering temperature;

Chilled-water leaving temperature;

Required temperature difference;

Water flow rate;

Required pump pressure;

Whether glycol is used;

Glycol type and concentration, if applicable;

Minimum and maximum operating water temperature.

Common conditions include 12/7°C and 7/12°C, but industrial process-cooling projects may require different conditions, such as 15/10°C, 20/15°C or other combinations.

A chiller used for plastic extrusion, injection molding, food processing, chemical production or other industrial processes must be selected according to the actual process requirements.

5. Check the Electrical Power Supply

High-ambient operation normally requires careful electrical evaluation because compressor and condenser-fan power consumption may increase.

The following information should be confirmed:

Voltage;

Phase;

Frequency;

Transformer capacity;

Available power at the installation site;

Short-circuit capacity;

Cable size;

Circuit-breaker rating;

Voltage fluctuation;

Starting current and running current;

Whether a soft starter or other starting device is required.

Typical power supplies in the region may include 380V/3Ph/50Hz, 400V/3Ph/50Hz, 415V/3Ph/50Hz or 380V/3Ph/60Hz, depending on the country and project.

The customer should also ensure that the complete electrical system-not only the chiller-is capable of supporting the equipment at full load.

6. Pay Attention to Installation and Airflow

A high-temperature chiller cannot operate reliably if the outdoor air cannot circulate properly.

The installation area should provide:

Sufficient clearance around the chiller;

No obstruction at the condenser air inlet;

No recirculation of hot discharge air;

Adequate distance between multiple chillers;

Sufficient maintenance space;

A firm and level foundation;

Proper drainage;

Protection from excessive dust and sand;

Protection from corrosive coastal air where necessary.

If the hot air discharged from the condenser returns directly to the air inlet, the actual entering-air temperature may become even higher than the outdoor temperature. This can cause high-pressure protection and unstable operation, even when the chiller itself has been correctly selected.

7. Consider Dust, Sand and Coastal Conditions

Many projects in the Middle East and Africa are located in desert, industrial or coastal areas. High temperature is not the only challenge.

The equipment may also be exposed to:

Sand and dust;

High humidity;

Salt air;

Corrosive atmospheres;

Unstable power supply;

Limited maintenance resources.

For these projects, the customer may need to consider:

Special condenser coil coating;

Corrosion-resistant materials;

Improved air filters or protective screens;

Stronger electrical protection;

Dust-resistant control cabinets;

Regular condenser cleaning;

Remote monitoring and alarm functions;

Recommended spare parts.

The final configuration should be selected according to the actual site environment.

HEAD-POWER High-Temperature Chiller Solutions

HEAD-POWER manufactures central air-conditioning equipment for a wide range of industrial and commercial applications, including:

Industrial process cooling;

Plastic extrusion and injection molding;

Food and beverage production;

Chemical and pharmaceutical factories;

Data centers and server rooms;

Hotels and hospitals;

Commercial buildings;

Warehouses and workshops;

Manufacturing plants;

Power and utility projects;

High-temperature desert applications.

Our engineering team reviews the customer's operating conditions before recommending the equipment. The selection may include air-cooled chillers, water-cooled chillers, screw chillers, scroll chillers, heat pumps or customized process-cooling systems.

The recommended solution depends on:

Required cooling capacity;

Project location;

Ambient temperature;

Chilled-water conditions;

Process requirements;

Electrical supply;

Installation arrangement;

Maintenance conditions;

Budget and delivery requirements.

Information Required for a Technical Selection

To recommend a suitable chiller, customers are requested to provide:

Project country and city;

Required cooling capacity;

Required quantity;

Chilled-water entering and leaving temperatures;

Required water flow rate;

Required water pressure;

Outdoor design temperature;

Power supply;

Application of the chiller;

Installation location;

Whether glycol will be used;

Required delivery term and destination port.

If the project is located in an area where the ambient temperature may reach 50–55°C, this condition should be stated clearly at the beginning of the inquiry.

Conclusion

For projects in Saudi Arabia, the UAE, Qatar, Kuwait, Bahrain, Oman, Yemen, Iraq, Jordan, Israel, Iran, Egypt, Libya, Algeria, Sudan, Mauritania, Mali, Niger, Chad, Somalia, Djibouti and other hot regions, chiller selection should be based on the actual design condition.

A standard chiller selected only by its nominal capacity may not be sufficient for a 50–55°C environment.

A reliable high-temperature chiller selection should consider:

Actual cooling capacity at the required ambient temperature;

High-ambient compressor and condenser configuration;

Chilled-water temperatures and flow rate;

Electrical power availability;

Installation ventilation;

Dust, sand and corrosion protection;

Maintenance and after-sales requirements;

Long-term operating reliability.

HEAD-POWER provides customized central air-conditioning and process-cooling solutions for high-temperature industrial and commercial projects.

If you are planning a chiller project in the Middle East or Africa, please send us your project location, required cooling capacity, chilled-water temperatures, water flow rate and power supply. Our engineering team will review your requirements and recommend a suitable solution for the actual site conditions.