Thermostats - Mechanical

Mechanical thermostats are bi-metallic strips or gas-filled bellows designed to regulate the temperature within a space by mechanically controlling heating or cooling systems. These temperature-sensing switches precisely monitor the temperature by detecting temperature changes turning the heating or cooling system on or off. Unlike their digital counterparts, mechanical thermostats operate without electronic components, relying on basic mechanical principles to regulate temperature. Additionally, a mechanical thermostat is known for its exceptional repeatability and positive response, providing precise and reliable switching and sensing in various applications. 

Advantages of Thermostats – Mechanical:

Using mechanical thermostats offers numerous benefits, such as:

• Durability: Without electronic components, mechanical thermostats are less prone to malfunction due to electrical issues.
• Cost-Effectiveness: They are generally cheaper to purchase and install compared to their digital counterparts.
• Ease of Use: With no programming required, they are straightforward and easy to operate.

Popular Types of Thermostats – Mechanical:

• Bimetallic Strip Thermostats – These thermostats use a bimetallic strip consisting of two different metals bonded together. Upon changes in temperatures, the expansion and contraction of metal cause the strip to bend. This bending action opens or closes the electrical contacts, controlling the heating or cooling system.
• Gas-Filled Thermostats – These thermostats use a gas-filled bulb connected to a capillary tube. When the temperature changes, the gas expands or contracts, causing pressure changes in the tube. These pressure changes actuate a mechanical switch, controlling the heating or cooling system.
• Wax-Filled Thermostats – Similar to gas-filled thermostats, wax-filled thermostats use a wax-filled element instead of gas. When the temperature changes, the wax expands or contracts, causing mechanical movement that operates the thermostat switch.
• Snap Action Thermostats – These thermostats use a snap-action switch mechanism––a type of switch that rushes between its two positions. Temperature changes cause the switch to "snap" from one position to another, turning the heating or cooling system on or off.
• Capillary Thermostats – These thermostats comprise a temperature-sensitive liquid-filled capillary tube connected to a diaphragm or bellows mechanism. Changes in temperature cause the liquid to expand or contract, which moves the diaphragm or bellows to open or close electrical contacts.

Ideal Applications of Thermostats – Mechanical:

Mechanical thermostats are best suited for residential, commercial, and industrial environments where simple and reliable temperature control is required. Some common uses of mechanical thermostats include:

• HVAC Systems
• Refrigeration Units
• Hot Water Heaters
• Space Heaters and Boilers
• Ovens and Furnaces.