how does a capillary thermostat work?

Some of our customers asked us how does a capillary thermostat work? A capillary thermostat is a type of temperature control device that uses a liquid-filled capillary tube to sense changes in temperature and control a switch that turns on or off a heating or cooling system.

The capillary tube is typically made of a thin, flexible material such as copper or stainless steel and is filled with a temperature-sensitive liquid, such as mercury or a special fluid. One end of the tube is placed in the area where the temperature is being measured, such as in a room or in a piece of equipment, and the other end is connected to a bulb that houses the thermostat's switch mechanism.

As the temperature in the area being measured changes, the liquid in the capillary tube expands or contracts, causing the bulb to move and activate the switch. If the temperature rises above the desired set point, the switch turns on a cooling system, such as an air conditioner or a refrigeration unit. If the temperature falls below the set point, the switch turns on a heating system, such as a furnace or a heat pump.

Capillary thermostats are commonly used in refrigeration and HVAC systems, as well as in other applications where precise temperature control is required. They are reliable and durable, and can be calibrated to maintain temperature within tight tolerances.