thermometer showing high temperature in city
The solar radiation produced by the sun is the source of all life on Earth, an infinite well of renewable energy and necessary for a pleasant day at the beach. However, for outdoor electronics manufacturers, it’s also a potential hazard for electronics that has to be managed.Heat and energy from the sun can easily overheat an enclosure and its contents, causing a wide range of issues. Choosing high-performance electronic enclosures helps to control and mitigate the effects of solar load on outdoor electronics enclosures. We’ll take a brief look at the basics of solar loading and then examine some of the options Polycase gives its customers for meeting these challenges.

Cooling Load, Solar Load and Why They Matter

Solar load is an aspect of the larger concept of cooling load, so to understand solar load, we first need to know what cooling load is. Cooling load (also called heat gain) refers to the amount of heat that must be removed from a space in order to keep it at an acceptable temperature. Solar loading or solar heat gain is one of several factors that contributes to a device’s total cooling load.Compounding these issues is the fact that with many devices, the internal heat load generated by the device’s operation is also adding to the cooling load by raising air temperatures inside the enclosure. Together or separately, these factors can create a need for temperature control measures for an enclosure.Effective management of solar load is key for any enclosure that will receive prolonged exposure to direct sunlight, especially outdoors. Enclosures for solar power equipment, of course, receive particularly high amounts of direct outdoor sunlight. But outdoor devices in general must withstand the elements at a higher level and, depending on the climate, solar load can be a major part of that.

Calculating Your Enclosure’s Solar Load

To get a rough idea of what your enclosure’s solar load will look like, you can use any of several enclosure cooling load calculators available online. You’ll need some basic information, such as the expected dimensions and applications of your enclosure.Keep in mind that these calculations will only be an estimate and that you’ll need to work with your engineering staff to identify the specific needs of your devices. A brief list of factors that may affect your individual performance requirements include:
  • What internal temperature your device needs to maintain
  • Whether a device will be in direct or indirect sunlight, and how often
  • The device’s active power load
  • Areas of the device that will receive the most sunlight (top, bottom, sides, etc.)
  • Climate and ambient temperatures the device will operate in
  • Size of the enclosure’s surface area that will be exposed to sunlight
  • Material that the enclosure is constructed from
  • Type of insulation in the enclosure
Once you know what kind of solar load you’ll be dealing with, you can start to examine the many solutions available.outdoor high voltage electrical box

How Can Solar Loading Be Managed?

Engineers and device designers use a wide variety of methods to reduce solar heat gain and prevent excessive temperature rise. We’ll discuss a few of them briefly here.Some of the easiest and most effective ways to manage solar loading begin with basic design decisions. One common example is simply choosing an enclosure color that will reduce the heat that the enclosure absorbs. By choosing a lighter color such as light gray or white rather than black or dark gray, you can considerably reduce the cooling load of a device’s enclosure. Most of our outdoor NEMA enclosures are available in light colors as a standard option.Another common strategy is to increase an enclosure’s heat transfer capacity by increasing its surface area. Greater surface area makes heat dissipation easier by providing a larger surface through which heat transfer is conducted. This practice can take multiple forms, from using slightly larger enclosure sizes to adding fin-shaped heat sinks to increase surface area.A wide variety of enclosure vent accessories are also available to create the airflow and cooling power your devices may need, including:
  • Passive airflow aids such as breather vents and louver vents
  • Forced air mechanisms such as blowers, heat exchangers, air conditioners and cooling fans
  • Customized ventilation cutouts using Polycase’s CNC machining service
Each of these offers its own set of advantages for thermal management. Which enclosures and cooling systems offer the best performance is a matter of what suits your needs most closely. Polycase offers several popular models of outdoor enclosures with superior performance against the elements in a variety of materials: No matter your enclosure needs, Polycase can help you find the solution that’s just right.Polycase SK-24 polycarbonate enclosure

Polycase’s SK-24 polycarbonate enclosure with knockouts

When designing devices that will be deployed in hot and sunny settings (particularly solar energy technologies), proper solar load management is critical for successful outcomes. Polycase’s flexible solutions can simplify your cooling load strategies and give you better electrical enclosures at competitive prices. Got questions? We’d love to help. Give us a call at 1-800-248-1233 or contact us online!
In Outdoor Electronic Enclosures, Heavy-Duty Electronics Enclosures