October 12 2025

Overview of Chiller Applications in Different Climate Conditions

Introduction

The chiller is the centrepiece of a refrigeration system and its operational reliability depends directly on the suitability of the design for the climate in which it operates. There is no one-size-fits-all solution: a standard model designed for air temperatures between -10 and 35 °C is often outside this range in real-life conditions.

According to industry surveys by Eurovent and AHRI, more than 60 per cent of unit failures are not due to manufacturer defects, but to unsuitable operating conditions, including climatic conditions. Improper adaptation leads to low condensing pressure, overheating of compressors, freezing of circuits and accelerated ageing of heat exchangers. At the same time, well chosen options – such as winter kit, free cooling or liquid injection – increase unit life by 25-40 % and reduce energy consumption by up to 30 %.

The experience of leading brands confirms that each manufacturer develops its own climate specialisation. Carrier and Trane are traditionally strong in universal models for temperate regions, YORK (Johnson Controls) and McQuay develop tropical versions with an extended range of condensing temperature up to 55 °C, and Daikin and Climaveneta bet on energy-efficient solutions for European climate with integrated heat recovery. Even Chinese brands such as Midea and Haier have adapted their ranges to cold zones in recent years, including equipment with crankcase heating and condensing pressure regulators.

If you need help selecting a chiller for your facility – contact EVROPROM engineers – we will find the optimal solution, taking into account your wishes and operational peculiarities.

Chiller operation in cold climates

Operation in countries with cold winters (Scandinavia, northern Germany and Poland) places special demands on the equipment. A basic chiller designed to start up at 10 … 12 °C will not work here – in winter the outside temperature often falls below -15 °C and in some regions it reaches -25 … -30 °C. For such conditions, manufacturers offer special equipment and technical solutions, which become mandatory.

Fig 1. Winter operating conditions of the chiller

Maintaining condensing pressure

The main problem at low outdoor temperatures is a drop in condensing pressure. If it is not compensated for, the thermostatic expansion valve (TRV) loses stability and the evaporator starts to operate with a vapour-liquid mixture, resulting in “make-up” and the risk of hydrostroke.

To solve this problem apply:

condenser fan speed control – step or smooth (VFD). Smooth control is preferable as it prevents pressure surges;
hot gas bypass – part of superheated vapour from the discharge is transferred to the liquid receiver or to the condenser inlet, which allows to maintain the minimum required pressure (7…9 bar for most refrigerants);
electronic TRVs – unlike mechanical ones, they are more resistant to pressure fluctuations and provide accurate refrigerant dosing at low loads.

Trane’s experience in Scandinavia shows that the combination of VFDs on fans with hot gas bypass ensures stable operation at temperatures down to -20 °C without additional condenser modifications.

Compressor crankcase heating

During long periods of freezing temperatures, the refrigerant condenses in the compressor crankcase. At start-up, this causes the liquid refrigerant to enter the oil, reducing its viscosity and causing rapid bearing wear. Screw compressors are particularly vulnerable when operating with large volumes of oil.

Therefore, an obligatory element of the winter set is an electric crankcase heater that maintains the oil temperature 10-15 °C above the suction line temperature. In Carrier and Daikin the heating is switched on automatically through an inbuilt controller, in some Italian brands (Climaveneta, Rhoss) simpler thermorelays are used.

Fig. 2 – Surface-mounted crankcase heating for small compressors

Fig. 3 – Recessed crankcase heating for medium and large compressors

Chiller selection

Water is rarely used as a coolant in cold climates. Propylene glycol (25-35 %) or ethylene glycol (20-40 %) solutions are used in almost all systems. Glycol guarantees freeze protection, but increases viscosity and reduces heat capacity.

This has two important consequences:

pumps consume 10-20 % more energy due to increased hydraulic resistance;
the heat transfer efficiency in the evaporator is reduced, so the evaporator area must be larger than in systems with water.

Daikin, in its Northern European series, has designed evaporators with a larger surface area specifically to work with glycol, whereas Chinese manufacturers often omit this, resulting in problems with undercapacity.

Free cooling as a key option

A cold climate opens up the possibility of saving on operating costs. At outside temperatures below 5 … 7 °C, some or all of the load can be removed via a dry cooler. In some regions (Germany, northern Poland, Scandinavia), free cooling allows up to 4000-5000 hours per year without compressors.

There are two main options here:

integrated free cooling (Trane, Climaveneta monoblocks) – more compact and easier to operate;
external dry cooler with bypass – more often used in industrial facilities with large circulation volumes.

Operating experience in Finland has shown that integrated free cooling systems save up to 30-35% of electricity per year compared to the traditional mode.

Fig. 4. – Schematic for integrating free cooling into an existing cooling system

Hydraulic protection

In addition to the insulation of pipework, the following are often used:

heating with heating cable, especially in open areas;
automatic circulation of the coolant during idle times to prevent freezing;
enlarged expansion tanks, as glycol has a higher coefficient of thermal expansion than water.

Climaveneta and Rhoss provide the hydronic modules with additional insulating casings. Carrier offers chillers for northern markets with factory-insulated pipe connections and integrated heating cables.

Thus, for cold climates, a unit without a winter kit and without adaptation to glycol is actually unsuitable. Operating experience confirms that the right winter kit and free cooling integration not only ensure reliable operation of the equipment, but also reduce operating costs by tens of per cent.

Chiller operation in hot climates

Operation in countries with hot climates (Egypt, Morocco, Saudi Arabia, UAE, Pakistan, India) is associated with extremely high outdoor temperatures of 40 to 50 °C and higher. In such conditions the basic chiller equipment designed for 35… 40 °C practically does not work: compressors overheat, condensers lose efficiency, automatics goes into protection. To ensure reliable operation, special technical solutions are used.

Higher demands on condensers

In hot climates, the condenser is the most vulnerable element.

Increased heat transfer surface. In standard European models, the condenser area is designed for outdoor temperatures up to 30 … 35 °C. For tropical designs, manufacturers increase the heat exchange surface by 20 to 30 %. For example, YORK and Carrier condensers in the “tropical version” have 2-3 more rows of tubes than in the European version.
Inter-lamella spacing. In the desert areas of Morocco and Saudi Arabia, high concentrations of dust and sand quickly clog the lamella spacing. For this reason, increased lamella spacing is used (2.1-2.5 mm instead of the standard 1.4-1.8 mm). This reduces the thermal coefficient, but ensures longer operation without cleaning.
High efficiency fans. In hot countries, axial fans operate at suction temperatures of up to 60 °C. For this reason, motors with higher insulation temperature resistance (class H) are used, as well as frequency control to optimise air flow.

Compressor operation at high temperatures

At condensing temperatures above 50 °C, the load on compressors increases exponentially.

Liquid injection. YORK and Trane screw compressors use liquid refrigerant injection in the interstage zone, which reduces discharge temperature by 10-15 K and prevents overheating of the windings.
Interstage subcooling. Carrier and Daikin use economiser type heat exchangers to cool the liquid refrigerant before it is fed to the evaporator. This increases cooling capacity and reduces compressor load.
Reinforced lubrication system. Oil viscosity drops at high temperatures. For this reason, tropical versions of compressors can be equipped with higher viscosity index oils and remote oil coolers.

Operating experience in Egypt shows that standard scroll compressors (especially small capacities) have a service life of 2-3 years with constant summer operation. Screw compressors with liquid injection work many times longer because they are more resistant to overheating.

Corrosion protection

In hot regions, the external environment has a critical influence on the service life of the equipment:

sea air (salt spray) on the Mediterranean and Red Sea coasts destroys aluminium lamellae in 1-2 years without protection;
sand and dust cause abrasion and clogging of condensers;
high solar radiation overheats electrical junction boxes, cabinets and plastic components.

For protection are used:

blygold, Baltibond, epoxy coatings – service life of capacitors increases 2-3 times;
anti-corrosion enclosures of electrical cabinets with IP55 class and additional ventilation;
thermal insulation of cable routes and sensors.

Carrier in Egypt produces heat exchangers with Blygold factory treatment. York offers proprietary CoilSAFE coatings for Saudi Arabia.

Figure 5. – Effects of salt spray on different types of anti-corrosion coatings

Power supply and automation

South Asia and Africa are characterised by unstable power grids. Voltage fluctuations of ±15 % are the norm in Pakistan and India.

YORK and Trane produce controllers with an extended power tolerance range (-20 to 15 %).
UPSs for automation systems are often integrated so that short-term outages do not result in a reset.
Control panels are equipped with additional fans or air conditioners to cool the electronics at 50 … 55 °C.

Typical cooling media

In hot climates, water is almost always used to cool the condenser. Glycol is not needed because there are no negative temperatures and unnecessary hydraulic resistance is undesirable. However, this leads to other problems:

higher water quality requirements (hardness, salts, corrosion);
the need for regular dry cleaning of circuits and evaporators.

Trane in Saudi Arabia equips evaporators with copper-nickel tubes that are resistant to salt water. In Europe, this option is much less common.

Thus, for hot climates, tropical design, compressor overheating protection and anti-corrosion coatings are key. A universal “European” unit without these options rarely survives in Africa or Asia – operation quickly reveals any weaknesses.

Take a look at our catalogue of chillers – units in various configurations, carefully checked for defects, adjusted to the required temperature regimes and shipped to you in perfect condition.

Chiller operation in temperate climates

Climate zones with moderate winters and not extremely hot summers (France, Great Britain, southern Germany, Ukraine, northern Italy) have different requirements for chillers than the north or the tropics. The outside air temperature here ranges from -5…-10 °C in winter to 30…35 °C in summer. Operation in such conditions is less likely to involve “critical” risks for the equipment, but this is where energy efficiency and system flexibility are most important.

Free cooling and energy savings

In temperate climates, the use of free cooling becomes one of the main tools for energy saving.

Hours of operation without compressors. In Europe, when the outside temperature is below 7 °C, the chiller can only run on dry coolers, saving compressor life. For data centres, this is up to 1500-2500 hours per year.
Integrated solutions. Trane, Climaveneta and Carrier offer models with integrated freecoolers. These units are more compact and easier to operate, but more expensive at the procurement stage.
External dry coolers. These are used in industrial facilities with large circulation volumes. York and Daikin have entire ranges of dry coolers that work in conjunction with chillers.

In practice, free cooling can reduce annual energy consumption by 25-35%. In the UK, server sites almost always use this technology.

Fig. 6 – Drycooler ALFA LAVAL S.p.a. VDDS906CD196, 779 kW for free cooling in our catalogue

Reversible chillers and heat pumps

Temperate climates are favourable for reversible chillers.

Heating operation. At outdoor temperatures as low as -10…-15 °C, the unit can operate efficiently in heat pump mode. This covers off-season loads in office and hotel buildings.
Energy optimisation. Daikin and Climaveneta promote models capable of switching “cooling ↔ heating” throughout the day, allowing flexible load management.
Heat recovery. In temperate climates, machines with partial or full recovery of condensing heat for DHW are often in demand. On average, this can cover up to 20-30 % of the building’s hot water demand.

Operating practice shows that such solutions are particularly in demand in Southern Europe and Ukraine, where the heating season is relatively mild and the demand for DHW is year-round.

Noise requirements

In urban areas (Paris, London, Milan), noise from refrigeration equipment becomes a factor in the limits of regulations.

Low noise fans. Fans with a larger diameter and low speed are used. Noise levels can be reduced from 60-65 dBA to 40-45 dBA.
Noise-isolating compressor housings. Carrier and Climaveneta produce monoblocks with factory-installed noise-insulating bonnets.
Inverter control. Frequency control of fans and compressors reduces noise at partial loads, which account for up to 70% of the operating time.

In London, Trane supplies “Low Noise” units for residential neighbourhoods where the acceptable level is only 35 dBA at the site boundary.

Environmental standards and refrigerants

Europe’s temperate climate coincides with a region of the most stringent environmental requirements (ErP, Ecodesign, F-Gas Regulation).

Switching to low GWP refrigerants. All major manufacturers offer chillers on R-1234ze (GWP<10), R-32 or R-513A.
SEER/SCOP energy efficiency. Minimum requirements of SEER > 4.5 and SCOP > 3.2 have become mandatory for new installations.
Flexibility of choice. In contrast to cold and hot climates, where the question “works/not works” is critical, in temperate zones the focus is on energy efficiency and compliance with directives.

Daikin is particularly active in introducing R-32 in small and medium-sized chillers. Climaveneta and Carrier rely on R-1234ze in medium and high capacity screw models.

Thus, in temperate climates, units rarely face extreme threats to their operating life, but this is where the competition between energy efficiency, recovery and acoustic comfort technologies comes into play. For the owner, this means that the key selection factor is not “equipment survival” but a balance of energy efficiency, operating comfort and environmental standards.

General practical recommendations

The selection of a chiller for a particular facility cannot be considered in isolation from climatic conditions, even when it comes to standard series and proven brands.

In cold regions, the key requirement is to ensure a stable condensing pressure and to protect the system from freezing. At the selection stage, it must be taken into account that the chiller must be able to operate at ambient temperatures as low as -15 °C and, in northern countries, as low as -25 °C. For this purpose, a winter condensing pressure maintenance kit, condenser fan control and compressor crankcase heating must be included.

In temperate climates, the priorities are different. Here, the main objective is to achieve high energy efficiency all year round. It is important to correctly select the outlet temperature of the chiller to ensure sufficient temperature difference for free cooling, and to provide for the possibility of heat recovery in advance. Very often the possibility of integrating partial modes or reversible cycles is ignored in the selection process, focusing only on the summer cooling capacity.

In hot climates, the design must start with a calculation of the heat loads on the condenser. The higher the outside air temperature, the more important the heat exchange surface and the ventilation efficiency. At temperatures above 45 °C without a tropical design, the unit loses stability: the automation goes into high pressure protection and the compressors run at critical discharge temperatures.

Conclusion

The operation of chillers in different climates is not a matter of brand, but of engineering adaptation. There is not and cannot be a one-size-fits-all solution for Scandinavia, Southern Europe and the Gulf.

Manufacturers offer a wide range of solutions: Carrier and Trane provide versatility and sustainability, YORK specialises in industrial units for hot regions, Daikin and Climaveneta focus on energy efficiency and environmental standards, and Chinese brands are gradually penetrating the mass market. However, regardless of the brand, the efficiency of the equipment will always depend on how well it is designed and prepared for the climate.

The main conclusion confirmed by practice: a properly adapted chiller works for decades without performance degradation, whereas a unit installed “as is” starts to create problems already in the first seasons of operation. Ultimately, the reliability of a chiller system is determined not by the passport data, but by the engineering logic laid down in the project. And this is where the engineer’s competence becomes the decisive factor – the one that turns a standard unit into a sustainable and efficient refrigeration system.

If you still have questions about equipment selection, please contact Europrom specialists. We will help you choose the right solution and offer reliable chillers presented in our catalogue.

What you get with EVROPROM

Optimal chiller selection for your tasks – we take into account operating modes, seasonal load fluctuations, reliability and energy efficiency requirements. We help you choose the optimal compressor type depending on the specifics of the facility.

Technical expertise and calculations – we provide energy efficiency comparisons (COP, EER), forecast operating costs, and calculate payback period for equipment replacement.

Up-to-dateand proven equipment – a wide range of chillers of world brands with different types of compressors and heat exchangers, adapted for industrial, commercial and infrastructure facilities.

Reduced operating costs – by using energy efficient solutions (turbo compressors, frequency control, optimised hydraulics) we reduce annual energy consumption and service costs.

Support at all stages – from the survey of existing systems and design to delivery, installation, commissioning and subsequent maintenance.

Author of the article:

Dmytro Lychak, CEO
12.10.2025