Foolproof Method for Calculating Heat Dissipation in Control Panels

Foolproof Method for Calculating Heat Dissipation in Control Panels

As electrical components become increasingly smaller and are more densely packed into electrical control panels, the amount of heat generated inside cabinets continues to increase. When considering heat dissipation in control panels it’s important to note what electrical equipment manufacturers specify as a maximum allowable operating temperature for their components.

Maintaining a maximum internal control panel air temperature of 95°F (35°C) helps promote higher operating efficiencies and longer electrical component life. It’s easy to overlook the importance heat dissipation plays in control panels and how it can affect electrical equipment reliability.

How Heat Dissipation Works in Sealed Unvented Control Panels

In order to protect against demanding environmental conditions most industrial applications will require sealed unvented control panels such as NEMA Type 12, 4, and 4X cabinets to protect the costly electrical components housed inside. Most applications will require a closed-loop cooling solution due to high ambient temperatures or to protect sensitive electrical components from excess dust and dirt.

While the heat producing electrical components increase the air temperature inside the control panel, the resulting heat is transferred through the walls of the cabinet to the cooler ambient air outside where heat dissipation occurs. If the ambient air were cold enough to maintain temperatures below maximum operating temperature for the electrical components, this would be a natural cost effective cooling solution, but this is rarely a viable option.

The overall cooling capacity needs to match or exceed amount of total heat load generated by the electrical equipment within the control panel when the ambient air temperature is lower than the cabinet air temperature.

How Heat Dissipation Relates to Control Panel Size

Besides ambient temperature, the physical size of a control panel is the primary factor in rate of heat dissipation. Larger control panels will have larger exterior surface areas, resulting in a lower temperature rise from the heat producing electrical components inside. Having an oversized control panel simply to increase the heat dissipation rate doesn’t make economic sense, since larger cabinets are more costly and may require excessive space.

The easiest method to calculate the surface area of the control panel is to use the following equation: Total Surface Area = 2(H x W) + 2(H x D) + 2(W x D), which includes all six sides of the control panel measured in feet. Any surface area not exposed to ambient air, such as wall mounted or free standing cabinet models without legs, must be subtracted from the total value.

Once the total surface area has been determined, the next step is to calculate the heat load produced by the electrical components.

Factoring in Heat Load Produced by the Electrical Components

The total heat load is established by adding together the heat dissipation of all individual components housed inside the control panel. This information can be obtained from the manufacturers of the electrical components and the resulting value is usually given in Watts.

Additional Heat Dissipation Factors to Consider

Although the heat dissipation calculation of a control panel is a simple one, the true impact of external influences can be more difficult to determine. The control panel’s properties such as color, material type and whether it is insulated or not must also be considered. Factors such as maximum ambient temperature, effects of local heat sources and solar heat gain must be included when calculating the control panel’s total heat load. The control panel’s properties such as color, material type and whether it is insulated or not must also be considered.

The combination of these factors, plus the heat dissipation and heat load values all play an important part in determining the associated cooling capacity requirements.

Heat Dissipation and the Enclosure Temperature Management Calculator

Installing the appropriate control panel temperature control solution is important in order to properly protect the valuable electrical equipment housed inside. To help ensure that you select the right cooling solution for your control panel, use the Enclosure Temperature Management (ETM) Calculator.

The ETM calculator will help determine whether the control panel cooling needs will require an air conditioner, an air to air heat exchanger or a filtered fan package. Additionally, results will show which size and type of air conditioner will provide the required cooling capacity offering the most energy and cost efficient operation.

Don’t Ignore Control Panel Temperature Control

Although the heat dissipation calculation of a control panel is a simple one, the true impact of external influences can be more difficult to determine.

Many electrical control equipment failures are caused by overheating due to improper control panel cooling, but could be avoided with proper temperature control planning. An excellent place to start is to download the free Thermal Management Guide: Meeting Control Panel Space Requirements and Avoid Overheating e-book to learn more about how to incorporate enclosure cooling into your design and keep equipment operating safely in a smaller control panel.

For additional help the experts at Thermal Edge are available to help you properly chose the correct control panel cooling system for your application.

How to Select an Enclosure Air Conditioner with the Right Cooling Capacity


How to select an enclosure air conditioner with the right cooling capacity

The selection of the right size enclosure air conditioner should be based on a careful assessment of the total heat load, ambient temperature variation, and the required enclosure temperature. If the air conditioner is larger than required, energy usage will increase and the unit will cycle excessively. Conversely, an air conditioner that’s too small will run continuously and not control the temperature properly. A number of factors need to be considered when choosing an air conditioner. Here is how to select an enclosure air conditioner with the right cooling capacity:

Continue reading

5 Ways to Find Electrical Enclosure Cooling Manufacturers



The process of finding manufacturers for your products these days is not half as complicated as it used to be. It is no longer necessary to flip through the pages of a local directory or the Yellow Pages to find an electrical enclosure cooling manufacturer. With the power of the internet, you have access to a wealth of information; you just need to know what your enclosure cooling needs are and how to look. Continue reading

6 Tips for Selecting a Sealed Electrical Enclosure & Cooling Package



Although many electrical enclosures are naturally ventilated, there are a number of sound technical reasons for using sealed electrical enclosures. These include keeping components clean, dry, and preventing ingress of corrosive materials and dust. However, modern electrical and electronic equipment generates a significant amount of heat that must be removed from the enclosure, and sealed electrical enclosures cannot rely on traditional ventilation or fans for cooling. Thus, closed loop cooling is needed to ensure internal temperatures are maintained at safe levels. Continue reading

5 Precautions to Take when Enclosure Cooling System Is Subject to Vibration


Precautions-enclosure-cooling-systemElectrical enclosure air conditioners installed in locations subject to vibration may fail unless special precautions are taken to prevent failure. These locations may include steel structures supporting heavy equipment, marine environments, and off-road equipment. Fortunately, it’s possible to mitigate the effects of vibration on enclosure air conditioners. Here are five steps that we, at Thermal Edge, take to proof our enclosure air conditioners subject to vibration. Continue reading

5 Dangers in Comparing Enclosure Air Conditioners from Different Manufacturers



For many projects, a buyer will insist on several bids from vendors before placing orders. This is a valid requirement but, unless care is taken when selecting enclosure air conditioners, products selected may not meet operational requirements because the comparison process doesn’t take into account aspects other than the initial price. Continue reading

How to Ensure Your Electrical Cabinet Cooling System Meets Safety Requirements


It’s important that your electrical cabinet cooling system complies with relevant safety standards. Units purchased for use in the USA should comply with UL and NFPA standards and those for other regions and countries with appropriate national standards.

Additionally, US employers are required to comply with the General Duty Clause of the OSH Act that requires them to keep the workplace free of serious hazards. Compliance will ensure your cabinet cooling systems meet local safety requirements.

UL 484

Continue reading