Absorption Refrigeration- A cooling cycle that uses heat as its energy source.

Air Entrainment- To draw along (as when a water stream carries entrained air bubbles.)

Anti Vortex Hood- A device located inside a cooling tower near the water outlet that smoothes the exiting flow so as to prevent a whirlpool.

Approach- The leaving water temperature minus the wet bulb temperature.

Bent- A structural assembly found in field erected cooling towers forming the skeletal frame. Such assemblies typically repeat every so many feet forming a bent line.

BFW- A description of a nozzle connection as BEVELED FOR WELDING.

Bleed- v. To intentionally waste water from a system in order to maintain an acceptable water quality. n. The water that is wasted from a system.

Blow Down- (Same as Bleed)

BTU- British thermal unit. The amount of heat that will increase the temperature of one pound of water 1 degree Fahrenheit.

BTUH- Rate of heat transfer in Btu/Hr.

Capacity Control Dampers- Airfoil blades placed at the discharge if a centrifugal fan that change position so as to regulate airflow.

Cavitation- The phenomenon that occurs in a water pump when the pressure becomes sufficiently low to allow vaporization of the fluid followed by a sudden collapse of the vapor bubble as it passes to the high pressure area of the pump.

Damper Controls- Pneumatic or electric actuators, sensors, crank arms, linkages, etc. used to position capacity control dampers.

Casing- That part of a cooling tower which encloses the wet deck fill or coil.

Cold Water Basin- The collection point near the bottom of a cooling tower for the collection of cooled water.

Composite- Construction material utilizing high strength glass materials in a precise order so as to maximize strength held in place by cured epoxy resins.

Cooling Tower Ton- 15,000 Btu./Hr.

Copper Sweat Adapter- A short piece of steel pipe joined to a short piece of copper pipe that allows the pipe installer to connect these difficult to join materials. The steel end is typically factory welded to the steel nozzle on OEM equipment allowing the connection to copper pipe in the field.

Counterflow- A cooling tower configuration where the air and water flow in opposite directions.

CTI- Cooling Tower Institute

Conductivity Monitor- A device that measures the ease with which electricity passes through cooling system water. Conductivity is directionally proportional to the amount of dissolved solids in the water and is used to initiate bleeding, feeding chemicals, etc..

Crossflow- A cooling tower configuration where the air and water flow at right angles to one another.

Cycles of Concentration- The number of times the solids content of water has been increased. Two fold = 2 cycles; Three fold = 3 cycles, etc..

Discharge Hood- See 'hood'.

Drift- Water that escapes in the cooling tower air discharge stream as water particles. (AKA Spit)

Dry Bulb- Temperature of air measured with a conventional thermometer with a dry bulb.

Eliminator- A device placed in the discharge airstream of a cooling tower that attempts to eliminate entrained water droplets. It works by rapidly changing the direction of airflow causing the heavier water particles to collide with the eliminator surface and fall back inside the tower.

Equalizer Line- A pipe connected between the cold water basins of multiple cooling towers. Its purpose is to force equalization of water levels.

Extended Surface- Fins placed on a coil to increase heat transfer.

Factory Mutual- An organization that sets various product standards. Insurance companies look to see if items such as cooling towers have earned Factory Mutual Approval and typically offer reduced rates for equipment that has been demonstrated as unlikely to burn in a fire.

Fan Deck- The upper horizontal surface surrounding the fan stacks of a draw-thru, propeller fan cooling tower.

Fan Stack- The circular, vertical air discharge plenum of a prop fan in a draw thru cooling tower.

Fill- Material added to a cooling tower to enhance evaporation. (AKA surface, wet deck)

Fogging- The visible plume that forms at the air discharge of a cooling tower caused by the formation of small condensed moisture particles under certain climatic conditions.

Girt- A structural element of field erected cooling towers . Used to connect bents.

HDG- Hot Dip Galvanized

Hood- as in 'Strainer Hood'. A sheet metal cover inside the cold water basin that channels water smoothly toward the water outlet. Designs typically incorporate a tapered shape that promotes uniform water entry near the basin floor so as to prevent a vortex and air entry to the exiting water stream. The hood is always near the strainer; Occasionally, it is incorporated into the strainer.

Hood- as in 'Air Discharge Hood'. A factory accessory or field constructed sheet metal duct extension to a blow thru cooling tower's air discharge. Sometimes straight sided but typically tapered to accelerate the discharge air from a cooling tower's enclosure. When applied to a closed circuit tower, a hood can also inhibit coil freeze-up by incorporating a positive closure damper and insulated side walls.

Hot Water Basin- Water collection area at the top of a crossflow cooling tower the bottom of which is perforated to distribute water over the wet deck fill.

Latent Heat- Heat which changes the properties of a material without changing its temperature.

Lintel- A transverse support member used to support heat transfer surface from the underside.

Louvers- Horizontal blades placed at the air inlet of some cooling towers to prevent water splash out.

MPT- Male pipe thread.

NEMA- National Electrical Manufacturers Association

ODP- Open Drip Proof

Pan- A water collection basin. Also, the lower half of a factory assembled cooling tower.

Pan Heater- An electrical resistance grid installed in the cold water basin to prevent freeze up.

Plenum- An empty chamber in the path of airflow allowing smooth air transition.

Plume- (See fogging)

Pony Motor- A small motor connected in parallel with a large motor for operation when reduced rotational speed is desired- such as for capacity control.

Prime surface- Heat exchange surface without the addition of fins.

Psychrometer- An instrument used to measure the amount of water in an airstream.

Psychrometric Chart- A graphical representation of the physical characteristics of air containing various amounts of moisture.

Pull Down- The temporary loss of water volume from a cold water basin that occurs at pump start up.

Pultruded Fiberglass- Glass reinforced structural members that are formed by pulling glass and resin through a heated die.

Range- A cooling towers inlet water temperature minus its outlet water temperature.

Remote Sump- A tank located below and somewhat distant from a cooling tower that accepts the cooling tower outlet water by gravity flow.

RETA- Refrigerating Engineers and Technicians Association

Sensible Heat- Heat which increases the temperature of a body to which it is added.

Serpentine- Snake like.

Snout- Squared discharge extension to a centrifugal fan scroll that introduces air into a cooling tower pan.

Solid Bottom Panel- Sheet metal that blocks air from entering the bottom of a centrifugal fan cooling tower. Used when the inlet air is ducted horizontally.

Sound Attenuator- A device attached to the air inlet or discharge (or both) of a cooling tower to reduce the operating noise level. Consists of baffles covered with sound absorbent materials.

Sump- A water collector at the bottom of a cooling tower. Occasionally mounted remotely. A basin.

Synchronous Speed- The speed a fan motor would attain if there were no load or inefficiencies. (900, 1200, 1800 or 3600 RPM)

TEAO- Totally Enclosed Air Over

TEFC- Totally Enclosed Fan Cooled

Ton- The rate of heat transfer represented by 2,000# of ice melting in a 24 hour period. (12,000Btu/Hr.)

Turn Down- The allowable percent reduction of inlet water flow to a cooling tower.

Velocity Recovery Stack- A hyperbolically shaped discharge plenum at the top of a draw through thru, prop fan cooling tower. The shape increases the efficiency of the fan by converting some of the velocity pressure to static pressure for increased air flow.

Vibration Cutout- A switching device that can turn off fan motors, initiate alarms, etc. when unacceptable vibration is encountered- as when a fan breaks or becomes unbalanced.

Vibration Isolators- Spring assemblies used to support mechanical equipment thereby reducing the transmission of vibration energy to the building structure.

Victaulic- A proprietary method of mechanically joining pipe that uses gaskets and clamps.

Water Hammer- The noise and vibration experienced by piping systems as a result of rapid deceleration of liquid flow- Such as that introduced by a closing solenoid valve.

Wet Bulb- The temperature read from the wetted bulb of a thermometer placed in a moving airstream.

Wet Deck- (See fill)

Wind Wall- An interior partition installed in a louver less, draw thru cooling tower to prevent wind from blowing through and carrying the falling water out and onto the ground.