Walk-in cooler
Larger, commercially refrigerated space. Often found in supermarkets or wholesale meat distribution centers.
Water-cooled condenser
See Condenser, water-cooled.
Water coil
A coil submerged in water to take advantage of the water's temperature.
Water defrosting
Use of water to melt ice and frost from the evaporator.
Water hammer
Noise generated by backpressure of watter when a valve is closed.
Water Spray
A filtering device in which air is blown through a spray of water, removing so1id contaminants, liquid contaminants, and water-soluble contaminants.
Watt
Unit of electrical power.
Wax
An ingredient in many lubricating oils that may. separate from the oil.
Wet bulb hygrometer
See Psychrometer.
Wet bulb temperature
Measure of the degree of moisture. It is the temperature of evaporation for an air sample.
Wet cell battery
Cell or connected group of cells that converts chemical energy into electrical energy by reversible chemical reactions.
Wet roof cooling
Method of heat reduction in a building in which a pond of water is kept on the roof at all times. Heat from the sun is dissipated through the evaporation of water, so the roof surface remains cool.
Wheatstone bridge
Electronic circuit consisting of resistors and a thermistor. A temperature change causes the bridge to become unbalanced, which sends a signal to the output device.
Wick system
Lubricating method used in external-drive motors.
Wind chill index
A measure of how cold it feels, based on dry bulb temperature and wind velocity.
Window unit
Air conditioner that is placed in a window.
Wobble plate
See Swash plate.
Work
A force applied over a distance.
Work hardening
Increasing the strength of a material. (normally a metal) by bending and deforming it.