What is a heat exchanger?
Types, uses, and benefits of heat exchangers
Controlling temperature is one of the most important challenges in industrial and commercial environments.
Whether within chemical plants and refineries or HVAC systems and data centers, equipment and processes must operate within strict thermal limits. Even minor temperature fluctuations can cause inefficiency, safety risks, or unplanned downtime.
That’s why heat exchangers are so essential. They regulate temperatures, improve energy efficiency, and enable critical processes to function safely and reliably. For many businesses, renting industrial heat exchangers can also provide a flexible way to manage maintenance schedules, handle peak demand, or respond to emergencies without committing to permanent capital investment.
This article explains what heat exchangers are, how they work, the different types available, and where they are most often used in industrial and HVAC systems.
How heat exchangers work
A heat exchanger is a device that transfers heat from one fluid to another without allowing them to mix. One fluid may be hot while the other is cold, and the exchanger enables thermal energy to pass between them through a conductive barrier, such as tubes or plates.
The working principle can be broken down into four basic steps:
- Fluid entry – one fluid enters the exchanger hot, while another enters cold.
- Flow across surfaces – the hot fluid travels through tubes, plates, or channels, while the cold fluid passes across them in a separate circuit.
- Heat transfer – thermal energy moves through the conductive material, cooling one stream while heating the other.
- Equilibrium – both fluids leave the heat exchanger closer in temperature, depending on design and operating conditions.
This process is critical for heating and cooling industrial fluids and gases, condensation and evaporation in production processes, and energy recovery to reduce waste and improve efficiency.
Several factors determine the efficiency of an industrial heat exchanger:
- Temperature difference – larger differences between the hot and cold fluids drive faster, more efficient heat transfer.
- Fluid flow arrangement – counterflow systems, where fluids move in opposite directions, are more efficient than parallel flow designs.
- Surface area – increasing the contact area between the fluids allows more heat to be exchanged.
- Materials – stainless steel, aluminum, and advanced alloys are commonly used for their strength, corrosion resistance, and thermal conductivity.
Common types of heat exchangers
Different industries and processes require different designs. The most common types of industrial heat exchangers include:
- Shell and tube – a bundle of tubes enclosed in a cylindrical shell. One fluid flows through the tubes, while the other circulates around them. This durable design is widely used in high-pressure, high-temperature conditions like refineries, petrochemical plants, and power stations.
- Plate and frame – thin, corrugated metal plates create a large heat transfer surface in a compact unit. Easy to clean and maintain, these are popular in food and beverage production, HVAC, and chemical processing. Food-grade plate and frame heat exchangers are built with sanitary stainless steel and hygienic fittings to meet FDA and USDA standards.
- Shell and plate – combining the strength of shell and tube with the efficiency of plates, this versatile design is used in HVAC, energy generation, and chemical industries.
- Air-cooled (fin/fan) – instead of water, these use fans to push air over finned tubes. This makes them ideal for remote or arid regions where water is scarce, such as remote industrial sites and energy generation facilities.
- Cross-flow – fluids move perpendicular to one another, providing a balance between efficiency and size. These are often deployed in data centers and electronics cooling. Specialized designs, such as Hastelloy C cross-flow exchangers, provide additional corrosion resistance.
- Large node – high-capacity exchangers engineered to withstand extreme pressures and temperatures. These are vital in petrochemical, refining, and heavy industry.
Each design is optimized for specific fluids, pressures, and environments, making careful selection essential for performance and safety.
Key considerations for trade professionals
When selecting or renting an industrial heat exchanger, engineers and facility managers should consider several practical factors:
- Performance requirements – the expected flow rates, pressures, and temperature ranges of the fluids.
- Materials of construction – choosing the right metals or alloys for corrosion resistance and thermal performance.
- Ease of cleaning and maintenance – especially important for food, beverage, and pharmaceutical applications.
- Space constraints – plate exchangers offer compact footprints, while shell-and-tube designs require more space but handle greater loads.
- Rental flexibility – renting heat exchangers provides immediate access to capacity during scheduled maintenance, emergencies, or seasonal demand without locking up capital in permanent equipment.
Aggreko offers one of the largest modular fleets of heat exchangers in North America. Our solutions are rigorously tested, easy to scale, and backed by experienced process engineers who can design and deploy solutions tailored to your operations.
Whether you need a short-term rental to cover a turnaround or a long-term solution to handle growing demand, Aggreko provides the equipment and expertise to keep your operations running smoothly.
Heat exchanger solutions for any industry
Heat exchangers are the backbone of modern industry. By allowing efficient heat transfer between fluids, they regulate temperatures, protect equipment, recover energy, and keep vital processes online.
For trade professionals, asking “what is the purpose of a heat exchanger?” is the first step to selecting the right solution. And with Aggreko’s industrial heat exchanger rental options, you can access reliable, scalable solutions without unnecessary CAPEX.
Learn how our heat exchangers can support your operations.