Mechanical temperature controls use sensing elements to detect the temperature of air, liquids, or surfaces. They control the temperatures of commercial refrigeration, agriculture, and commercial and industrial heating and cooling installations. Air-coil and bimetal sensor temperature controls monitor the ambient air temperature. Remote-bulb sensor temperature controls have a capillary tube and sensor that monitors and regulates the temperature of the ambient air, a liquid, or a gas at a distance away from the control. Direct-immersion thermowell temperature controls include a thermowell assembly to monitor and regulate the temperature of liquids. Pipe-mounted sensor temperature controls surface-mount on pipes to monitor and regulate the temperature of the liquid flowing within the pipe. HVAC thermowells protect temperature sensors from flow, high pressure, and harsh environments. Proportional temperature controls optimize HVAC system operation to reduce energy usage.