How does a refrigeration system for a water dispenser work?

Summary

In a world increasingly focused on well-being and environmental sustainability, water dispensers equipped with refrigeration system are an optimal solution for offices, schools, HoReCa facilities and water houses. We at DKRspecialists in the field, we want to explain in detail how these systems work, to help you better understand the technology behind a 'simple' glass of fresh water.

The basic principle of a refrigeration system: no production cold, heat is withdrawn

Contrary to what one might think, a refrigeration system does not 'produce' cold. The process is based on a fundamental physical principle: the transfer of heat from a warmer element to a colder one. When we speak of water refrigeration, therefore, we are actually describing a process of subtraction of the heat present in the water itself.

This concept is crucial to understanding the functioning of any cooling system. Thermal energy is transferred from the water we want to cool to another element, through a complex but extremely efficient thermodynamic cycle.

The refrigeration cycle: the heart of the system

The refrigeration process in water dispensers exploits the thermodynamic properties of specific refrigerants. These fluids have the characteristic of changing state (from liquid to gaseous and vice versa) under certain pressure and temperature conditions, absorbing or releasing energy in the form of heat during these transformations.

The phases of the cycle

1. Compression: The cycle begins with the compressor, the real engine of the system. This component compresses the refrigerant in its gaseous state, increasing both its pressure and temperature. The hot, high-pressure gas is then conveyed to the condenser.
2. Condensation: in the condenser, the hot gas gives up its heat to the external environment. During this process, the refrigerant cools to condensation, changing from a gaseous to a liquid state, but maintaining high pressure.
3. Expansion: The high-pressure liquid passes through a separating element (expansion valve or capillary) which creates a drastic pressure reduction. This expansion causes the temperature of the refrigerant to drop significantly.
4. Evaporationcold, low-pressure refrigerant enters the evaporator, where it absorbs heat from the water we want to cool. As it absorbs heat, the refrigerant evaporates, returning to a gaseous state. The gas then returns to the compressor to begin a new cycle.

The main components of a refrigeration system

Each chilled water dispenser is equipped with specific components that work in synergy:

• Compressor: available in different types (hermetic, semi-hermetic, scroll), it represents the beating heart of the system
• Condenser: can be air- or water-cooled, depending on the application
• Evaporator: the zone where heat exchange takes place with the water to be cooled
• Expansion valve: thermostat or capillary, regulates refrigerant flow
• Thermostat: controls and maintains the desired temperature

The importance of correct dimensioning

We at DKR know that there is no such thing as a universal solution when it comes to refrigeration. Every environment - be it a office, one schoola restaurant or a water house - has specific needs that require careful evaluation.

The heat balance: a fundamental starting point

The dimensioning of a refrigeration system always starts with an accurate heat balance. 

This process analyses:

• Volume of water to be cooled: how many litres must be available throughout the day
• Temperature: the difference between the initial water temperature and the desired final temperature
• Time of use: the distribution of consumption throughout the day
• Environmental conditions: temperature and humidity of the installation site
• Consumption peaks: times of maximum use (lunch breaks in offices, recess in schools)

The evaporator: the heart of heat exchange

Of all the components in the refrigeration system, the evaporator deserves special attentionand in our industry, being the element where heat transfer from the water to the cooling system takes place. The process uses an intermediary means of heat exchange: in a typical refrigeration tank we find two systems of coils - the central circular coils where the water to be cooled flows and the external rectangular coils of the evaporator with the refrigerant fluid - both completely immersed in process water that acts as a thermal bridge.

This water is often partially frozen, creating the so-called 'ice bank' which guarantees constant temperature and increased cooling capacity. However, the ice bank is only one of the available solutions: there are 'dry' systems without intermediate fluids, 'direct' systems with immediate contact between evaporator and water circuit, or 'immersion' systems for specific needs. There is no universally best solution: each technology has characteristics that make it ideal for certain applications, depending on the volume of water, frequency of use, available space and environmental conditions.

Sector-specific applications

Offices

For working environments, we recommend quiet systems with adequate capacity for peak consumption during breaks. Simplified maintenance is an important plus.

HoReCa sector

Restaurants and hotels need high capacity systems, often supplemented with options for sparkling water. Reliability during services is crucial.

Water houses

Public installations requiring robust, weatherproof systems with high continuous delivery capacity.

Energy efficiency and sustainability

Modern refrigeration systems are designed with an eye on energy efficiency. We use environmentally friendly refrigerants and high-efficiency components that reduce electricity consumption. The investment in a quality system pays off over time through:

• Lower energy consumption
• Low maintenance
• Longer equipment life
• Elimination of plastic bottles
• Maintenance and longevity

A well-maintained refrigeration system can last over 20 years. Regular maintenance includes:

• Cleaning of condensers
• Controlling operating pressures
• Temperature verification
• Periodic sanitising of hydraulic circuits

The value of professional advice

Choosing the right refrigeration system for your water dispenser is crucial to ensure efficiency, reliability and user satisfaction. We at DKR offer our experience to guide you in selecting the most suitable solution for your specific needs.

Whether it is a small office or a large public facility, the principle remains the same: provide fresh, quality water that is environmentally friendly and energy efficient. Our technicians are always available to carry out inspections and correctly size the most suitable system for your reality.

Investing in a professional refrigeration system means ensuring the well-being of your employees, customers or users, while at the same time helping to reduce environmental impact through the elimination of plastic bottles. A small gesture that makes a difference, supported by sophisticated but reliable technology. For any information, we invite you to contact us.