Any time you're buying a case to hold powered-up electrical equipment, cooling should be a top concern. Without it, signals degrade and electronic components are likely to fail. Convective airflow (letting cool air in at the bottom and warm air leave from the top) might be appropriate for low ambient temperature, dust-free conditions. But most applications need a more sophisticated solution.
Sierra Cases offer three cooling technologies: heat exchangers and fans, air compressors, and thermoelectric coolers. Each has different performance characteristics, and, of course, costs. So, the technology should be matched to the application. There are two primary considerations: the environment in which the case will be deployed and the case payload. Within each of these, there are a series of secondary questions to address. In addition, the case itself has a bearing on the preferred technology.
What is the anticipated peak ambient temperature?
Will the case be in direct sunlight or close to another heat source?
What level of humidity is expected? Unless the system is designed for humid conditions, high levels can create condensation problems.
Will the case be deployed in dusty conditions? This usually precludes using fans and heat exchangers.
What is the lowest temperature expected? Depending on humidity and expected low, it may be advisable to add supplementary heating.
How much heat will be produced inside the case?
How hot can the case interior be allowed to get?
Is there a minimum allowable temperature? Desert environments can see low nighttime temperatures. Many electronic components or systems are not warrantied below a minimum temperature.
External dimensions (length x width x height). This determines how much air can be circulated internally.
What external power will be available – 120 VAC, 220 VAC or only DC?
Case color. Some cases are available with a special, heat-reflecting transparent coating. But in general, if the case will be in full sun a light color is recommended to reduce the solar load.
Air conditioner mounting location. Rear mounting is preferred, but front, side or top are possible. Thermoelectric coolers can be mounted in almost any orientation.
Is a remote monitoring required?
Every application is unique
When a transit case houses operational electronics, it's essential to engineer an application-specific cooling solution. At best, not doing so results in unnecessary cost. At worst, mission-critical equipment will fail. Ask Sierra Cases for advice.
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