Thermostat vs. Hygrostat Based Approaches to Monitoring Condensation in Electrics

Thermostat vs. Hygrostat Based Approaches to Monitoring Condensation in Electrics


HygrostatCondensation is one of the more overlooked factors in electrical component failure. Condensation can build in electrical enclosures, thus shortening the lifespan of components and causing safety hazards.

Equipment that is used or stored outdoors is particularly vulnerable to this, since the enclosure will be trying to maintain an environment against a range of ever-changing temperature and humidity conditions outside.

Electronics in these environments typically have a heating element to help protect them. This helps ensure the electronics are kept at a safe temperature for operation, and that condensation doesn’t form and collect inside the enclosure. Such heaters are typically operated via thermostats and hygrostats. Yet which is the better option?

North American Clean Energy compared the two using solar tracking controls for solar panel farms that would be used across North America. The enclosure they were monitoring was three feet by two feet by 10 inches. The thermal management system needed to handle ambient temperatures as low as -40 degrees Fahrenheit and maintain a range of dew points. A 700 watt heater was used to maintain a minimum temperature of 40 degrees Fahrenheit.

Using these parameters, they tested a heating unit using a thermostat and using a hygrostat. To control condensation, the thermostat was set at 77 degrees Fahrenheit. That’s rather high but necessary, and since the thermostat needed to heat the controls at all times when the temperature was below 77 degrees, energy costs and the heater’s lifespan were being wasted when the dew point itself was below 77 degrees.

Comparatively, the hygrostat disregarded temperature and focused on relative humidity. It was set to maintain 65-percent relative humidity, meaning the heater only had to raise the temperature of the interior by about 9 degrees compared to exterior conditions in order to prevent condensation.

They found under these conditions, the thermostat required much more wattage and burned through its lifespan more quickly. The cost of controlling condensation via thermostat was $132 per tracking system controller. For a hygrostat, the cost was $32.

For areas where cold and humidity must be controlled for, a hygrotherm is recommended, since regardless of humidity, equipment also must be kept above freezing conditions. Nonetheless, this demonstrates that when controlling specifically for humidity, a hygrostat-based using hygrometer technology is far preferable in cost-savings to thermostat-based approach. For any equipment you’re operating and maintaining, we’re happy to talk in-depth about your needs and guide you through the process of what’s most effective and what will save you the most in your energy bills.