Thermohygrostat for electrical enclosures

A thermohygrostat is a climate control device that maintains optimal temperature and humidity levels within electrical enclosures. By preventing condensation, it safeguards against corrosion, insulation breakdown, and electrical malfunctions. The thermohygrostat works in conjunction with heaters, dehumidifiers, or ventilation systems to activate heating or cooling as needed, ensuring a stable environment and preventing moisture buildup that can damage sensitive electrical components.

Types of thermohygrostat

Thermohygrostats primarily come in two types: mechanical and digital.

Mechanical Thermohygrostat

A mechanical thermohygrostat is a device that regulates temperature and humidity using mechanical sensors, such as bimetallic strips for temperature control and hygroscopic materials for humidity detection. It operates without electronic components, making it highly reliable and maintenance-free. When preset thresholds are reached, it activates heaters, fans, or dehumidifiers to maintain optimal conditions. Commonly used in industrial enclosures and electrical cabinets, mechanical thermohygrostats offer a cost-effective and durable solution for preventing condensation and ensuring equipment protection.

Mechanical Thermohygrostat

Digital thermohygrostat

A digital thermohygrostat (like Blue Jay’s WSK-72 Series Digital Thermostat and Humidity Controller) is an advanced control device that precisely regulates temperature and humidity in electrical enclosures. Equipped with a digital display and electronic sensors, it provides accurate real-time monitoring and allows users to set precise thresholds. When temperature or humidity exceeds the preset values, it activates connected devices such as heaters, fans, or dehumidifiers to maintain optimal conditions. Digital thermohygrostats offer improved accuracy, ease of use, and better adaptability compared to mechanical models, making them ideal for industrial control panels, switchgear cabinets, and other sensitive electrical systems.

Mechanical Thermohygrostat vs. Digital Thermohygrostat

Both mechanical and digital thermohygrostats serve the purpose of regulating temperature and humidity in electrical enclosures. However, they differ in operation, accuracy, and functionality. Below is a detailed comparison:

Specification	Mechanical ThermoHygrostat	Digital thermohygrostat
Working Principle	Uses bimetallic strips for temperature control and hygroscopic materials for humidity sensing.	Uses electronic sensors for precise temperature and humidity detection.
Control Method	Mechanical switching based on expansion/contraction of materials.	Digital display with electronic switching and precise control.
Accuracy	Moderate accuracy due to mechanical components.	High accuracy with real-time electronic sensing.
Display & Interface	No display, uses simple mechanical adjustment knobs.	Digital display with adjustable setpoints for better user control.
Response Time	Slower response due to mechanical operation.	Faster response with real-time monitoring.
Power Consumption	Low, as it operates without complex electronics.	Slightly higher due to digital components.
Reliability & Durability	Highly durable, operates without electricity or complex circuits.	Reliable but depends on power supply and electronic components.
Ease of Use	Simple setup, requires no programming.	More user-friendly with precise settings and display.
Cost	Generally more affordable.	Higher cost due to advanced features.
Application	Suitable for basic environmental control where high precision is not required.	Ideal for applications needing precise temperature and humidity regulation.
Power Supply	120V-230V	85V~265VAC/DC
Temparature setting range	0/+60ºC	-20~99℃
Relative Humidity setting range	30-90RH%	0~99%RH
Relative Humidity hysteresis	5%	5%
Reaction time	60sec	1s
Max. switching current	3-10A	5-10A
Contact type	Changeover
Installation position	Vertical, din rail	Panel mounting
Dimension	68x53x38mm,695350mm	72 x 72 x 96mm,484890mm
Signal Input	Fixed temperature and humidity, not selectable	High selectability of temperature and humidity channels: 1 temperature and 1 humidity; 2 temperatures, 2 humidity, etc. 1 channel or 2 channels with relay outputs

Conclusion

Mechanical thermohygrostats are cost-effective, durable, and require minimal maintenance, making them suitable for basic enclosure protection.

Digital thermohygrostats offer higher accuracy, real-time monitoring, and better control, making them ideal for environments where precise humidity and temperature management is essential.

Choosing the right type depends on the specific requirements of the electrical enclosure and the level of control needed.