It’s an almost universal truth that sensitive electrical devices require a carefully controlled environment to function efficiently and reliably. Excess heat, condensation, or contamination within an enclosure can lead to component failure, costly downtime, and reduced service life. What’s more, as electrical and automation systems become more compact and densely packed in modern systems, it’s more important than ever to maintain the right climate inside enclosures.

With more than 20 years of experience to our name here at LED Controls, we provide a diverse range of enclosures and climate control for a variety of industries – so this week, we thought we’d take a look in a little more detail about some of the key principles involved in getting the most out of yours.

Climate control in enclosures is more important than ever

Reliable enclosures play a vital role across all industries. In food manufacturing, they must be tightly sealed against water and food residue to ensure hygiene and easy cleaning. In contrast, data centres require enclosures designed for maximum reliability, as even minor overheating can cause system failures and service interruptions.

As we’ve touched on above, as electrical systems become more compact, component density within enclosures increases accordingly. This leads to greater heat generation, which can raise the risk of malfunctions if excess heat is not properly dissipated. That means managing internal temperatures becomes more vital than ever – just a 10°C rise beyond a component’s maximum permissible temperature can halve its service life.

So, airflow must be carefully controlled to ensure optimal performance, particularly in densely packed enclosures where hot spots can form. Regulatory compliance is another major priority – standards like DIN EN IEC 61439 specify heat detection requirements for low-voltage switchgear. It’s also worth bearing in mind that if proof of compliance is not provided, that can give rise to issues around liability, or insurance complications.

Key climate control considerations when designing your enclosure

As you might expect, designing an enclosure is quite an involved process, as each design is so heavily dependent on the intended application. To cover the broad strokes though, designing an enclosure with proper climate control always needs to begin with a detailed assessment of environmental conditions, future scalability, and cooling requirements. These factors determine the effectiveness of heat dissipation and the long-term reliability of the components inside. Otherwise, it can result in overheating, condensation, or inefficient cooling solutions that drive up operational costs.

Below are some of the most critical considerations for enclosure climate control.

Placement

The location of an enclosure plays a crucial role in its ability to maintain a stable internal temperature. If possible, enclosures should not be placed in direct sunlight, next to heat sources, or in confined spaces where airflow is restricted. However, in industrial settings, it’s not always possible (or practical) to avoid hot areas. In such cases, additional cooling solutions may be necessary to offset high ambient temperatures and prevent overheating.

Other environmental factors also need to be considered – including such as dust, moisture, and air quality. Contaminants can interfere with cooling efficiency or damage sensitive electronics, so if it’s a concern, enclosures may need to be fitted with enhanced sealing or filtered cooling solutions.

Scalability

Climate control should be designed not only for current needs but also for future expansion. Additional components may increase heat output, potentially exceeding the capacity of an enclosure’s existing cooling solution. To maximise long-term reliability, it’s therefore essential to ensure that there is enough space to accommodate future installations, without compromising airflow or cooling efficiency.

Similarly, if the enclosure is due to be fitted with additional features or equipment in future, it’s important to assess whether the enclosure's temperature will remain within safe operating limits. If you think the cooling capacity may become insufficient, it may be worth upgrading the climate control system.

Heat dissipation

An effective heat dissipation strategy is key to maintaining an enclosure's internal temperature within permissible operating limits. The right method depends on multiple factors, including the heat load, ambient conditions, and enclosure design. Passive methods, such as natural convection, may be suitable in some cases, while more advanced cooling solutions may be required for high-performance systems, such as air-to-air or air-to-water heat exchangers.

A quick recap on key principles of heat transfer

Heat is transferred in three main ways – radiation, conduction, and convection. It’s sometimes worth quickly refreshing yourself on these principles before you make your final decision on choosing the right enclosure cooling solution.

Radiation involves heat being emitted in the form of electromagnetic waves. In an enclosure, components release heat that radiates towards cooler surfaces. However, radiation alone is not an efficient cooling method, as heat must still be removed from the system to prevent accumulation.

Conduction involves heat moving through solid materials, such as the metal walls of an enclosure, spreading from hotter areas to cooler ones. If an enclosure is in contact with a cooler surface, heat will transfer outwards. However, if an enclosure is insulated or surrounded by warm air, this generally limits conductive cooling.

Convection involves heat being carried away by moving air or liquid. In an enclosure, natural convection occurs when warm air rises, creating circulation that helps dissipate heat. This process is slow and may be insufficient in high-power applications. Forced convection, such as with fans, actively moves air to improve cooling efficiency.

Crucial methods to dissipate heat

A range of cooling solutions can be used to manage heat inside enclosures, each suited to different environments and requirements. These include:

  • Natural convection
  • Fan and filter units
  • Air/air heat exchangers
  • Air/water heat exchangers
  • Cooling devices

The choice of cooling method depends on factors such as required temperature levels, air quality, and the availability of cooling water. Below, we explore some of these methods in more detail.

Natural convection

Natural convection is the simplest and most energy-efficient form of heat dissipation. Warm air inside the enclosure rises, while cooler air enters from below, creating a natural airflow cycle. This method works best in enclosures with good ventilation and when the ambient temperature is lower than the enclosure’s internal temperature. However, natural convection alone can sometimes be insufficient in high-power applications or tightly sealed enclosures, necessitating the use of fans or other cooling solutions.

Fan-and-filter units

Fan-and-filter units provide active cooling by drawing in ambient air and circulating it across enclosure components. The air is expelled through an outlet filter, removing excess heat. This method is widely used due to its cost-effectiveness and ease of installation. However, the quality of incoming air must be considered – if it contains dust, oil, or other contaminants, the filter will need regular maintenance to prevent clogging and protect internal electronics.

Air/air heat exchangers

Air/air heat exchangers offer a closed-loop cooling solution, making them ideal for enclosures exposed to dust, oil, or aggressive airborne substances. They work by transferring heat from the internal air to the cooler ambient air using a heat exchanger, without allowing external contaminants to enter. The effectiveness of an air/air heat exchanger depends on the temperature difference between the enclosure and the environment, with performance typically measured in watts per kelvin (W/K).

Air/water heat exchangers

Air/water heat exchangers deliver highly efficient cooling in compact spaces. They operate by transferring heat from the enclosure air to a water circuit, which carries it away. This method is particularly effective in environments with high heat loads and where a reliable supply of cooling water is available. Due to their superior thermal efficiency, air/water heat exchangers are often used in demanding industrial applications.

Cooling unit

Cooling units provide precise temperature control, making them the most effective solution for enclosures operating in high ambient temperatures. Unlike passive cooling methods, cooling units can actively reduce the internal temperature to below the surrounding environment. Careful positioning of air intake and outlet openings ensures even distribution of cool air, preventing localised overheating. The required cooling capacity of a unit is determined by factors such as internal heat load, ambient temperature, and the efficiency of airflow circulation.

Heating

While excessive heat is a concern, maintaining a minimum temperature inside an enclosure is equally important. If the surrounding environment is too cold, this can cause condensation to form, leading to moisture damage and electrical failures. In these cases, heating elements may be required to prevent temperatures from dropping too low. However, it’s worth taking extra care to ensure that no enclosures are heated beyond what is necessary, as this wastes energy and increases operational costs.

This is not an exhaustive guide, but designed to provide some useful insights to help you get the most out of your enclosures. And if you ever need to replace any of your existing enclosures, or bring in new ones to expand your operations, you can always count on us here at LED Controls to provide the very best prices.

With more than two decades of experience behind us, we supply a wide range of components, including enclosures, programmable logic controllers, variable speed drives, and motor control gear equipment. Feel free to explore what we have available – and of course, if you ever have any questions or need any advice, you can always give us a call on 01706 242050. Our team is here to help!