As energy costs and regulatory demands for system efficiency increase, thermostatic expansion valves (TXVs) are replacing capillary tubes, particularly in residential air conditioning and heat pumps.

The capillary tube has been used as a refrigerant metering device for many decades. Many HVACR manufacturers are still successfully employing capillary tube metering devices in their latest equipment.

Fill a narrow glass capillary tube with water, then turn it horizontal. Conventional wisdom says that the water will remain inside the tube. But a group of scientists in Spain and the UK has found ...