Cooling Glossary: Essential Cooling and Ventilation Terms

Based on the cooling topics covered throughout the Puravent Insights library, this glossary provides definitions of the most commonly used cooling and air movement terms.

A

Air Circulation

The movement of air within a space to improve temperature uniformity, comfort, and ventilation effectiveness.

Air Circulator

A fan designed specifically to move large volumes of air around a space rather than exhaust or introduce fresh air.

Air Changes Per Hour (ACH)

The number of times the air within a space is replaced in one hour.

Apparent Cooling

The cooling sensation created when moving air increases the evaporation of moisture from the skin. Apparent cooling lowers perceived temperature without reducing the actual air temperature. This principle is widely used in industrial and livestock cooling.

B

BTU

BTU stands for British Thermal Unit. A British thermal Unit is a traditional unit of energy defined as the heat required to raise the temperature of one pound of water by one degree Fahrenheit. It is a now seldom used unit of measurement for cooling and heating equipment. There are 3412 Btu to a1 KW

C

Cooling Load

The amount of heat that must be removed from a space to maintain the desired temperature.

Cold Storage

A temperature-controlled environment used to preserve food, pharmaceuticals, and other temperature-sensitive products.

Cross Ventilation

A ventilation strategy where air enters through one opening and exits through another, creating natural airflow through a building.

D

Destratification

The process of mixing warm air accumulated at ceiling level with cooler air at floor level to create a more uniform temperature. HVLS and destratification fans are commonly used for this purpose.

Dry Cooler

A heat rejection device that removes heat from water, glycol, or process fluids using ambient air. Unlike cooling towers, dry coolers operate without direct water evaporation. They are commonly used for process cooling and free cooling applications.

E

Evaporative Cooling

A cooling method that uses water evaporation to reduce air temperature. Warm air passes through wetted cooling media, causing water to evaporate and cool the air.

Evaporative Cooler

A cooling system that uses evaporation rather than refrigeration to provide cooled air. Often used in warehouses, workshops, and industrial buildings.

F

Fan Throw

The distance that air can effectively travel from a fan before velocity reduces significantly.

Free Cooling

A cooling strategy that uses naturally cool outdoor air or low ambient temperatures to reduce reliance on mechanical refrigeration systems. Dry coolers are frequently used in free cooling applications.

H

Heat Load

The total amount of heat generated within a space by occupants, equipment, lighting, solar gain, and processes.

Heat Stress

A condition where humans or animals cannot effectively dissipate body heat. In livestock, heat stress can negatively affect welfare, productivity, fertility, and feed intake.

HVAC

Heating, Ventilation, and Air Conditioning. The collective systems used to control indoor environmental conditions.

HVLS Fan

High Volume Low Speed fan. A large-diameter fan designed to move significant volumes of air efficiently over large areas while operating at relatively low rotational speeds. Widely used for cooling and destratification

I

Industrial Cooling Fan

A fan used to provide cooling through air movement in industrial and commercial environments.

Industrial Air Circulator

A high-performance fan designed to create consistent airflow across large industrial or agricultural spaces.

M

Misting Fan

A fan that combines airflow with a fine water mist to provide enhanced cooling through evaporative effects.

Monobloc Air Conditioner

An air conditioning system where all refrigeration components are contained within a single unit, eliminating the need for an external condenser.

O

Oscillating Fan

A fan that rotates from side to side to distribute airflow across a wider area.

P

Process Cooling

The removal of heat from industrial processes, machinery, or manufacturing operations to maintain operating temperatures.

Psychrometrics

The study of air properties, including temperature, humidity, and moisture content, used in HVAC and cooling system design.

R

Relative Humidity (RH)

The percentage of moisture in the air compared with the maximum amount the air can hold at that temperature.

S

Spot Cooling

Providing cooling to a specific area, workstation, machine, or group of occupants rather than an entire building.

Static Pressure

The resistance that fans and ventilation systems must overcome to move air through ductwork, filters, and equipment.

T

Thermal Stratification

The natural tendency for warm air to rise and cooler air to remain at lower levels within a building.

Ton of Cooling

A cooling capacity measurement equivalent to approximately 3.5 kW of cooling output.

V

Ventilation

The process of supplying, extracting, or circulating air within a building to control temperature, humidity, and air quality.

Variable Speed Control

A method of adjusting fan or cooling system output to match changing operating requirements, improving energy efficiency.

W

Wall Mounted Fan

A fan mounted above floor level to provide airflow without occupying valuable workspace. Common in warehouses, workshops, gyms, and livestock buildings.

Wet Bulb Temperature

The lowest temperature achievable through evaporation. It is a key factor when evaluating evaporative cooling performance.

Heat Load	Watts	BTU
Average The Room Is A Normal Residential Room, Office, Reception Area Or Similar, Where There Is Not Overly Crowded With People, Computer And Office Equipment.
Above Average There Are Factors That Contribute To Additional Heat Being Generated In The Room E.G. Strong Lighting, Overcrowding With People And Office Equipment, Conservatory Type Room, Or Flat Roofed Room.
High There Are Factors That Contribute To A High Heat Load In The Room. E.G. Commercial Cooking, Much Computer And Server Equipment, Switchgear, Temporary Building With Thin Walls And Flat Room, Plain Glass Conservatory.

Variable	Units	Notes/Guidance
System Airflow	M3/Hr	If you have it in cfm then multiply your cfm value by 1.7 to get m3/hr
Average Combined Pressure Drop Of Filters Of Higher Than F6 Efficiency	Pascals	F8 bag filters pressure drop - typical clean clean to dirty, 160 - 250 Pascals F9 compact filters pressure drop - typical clean to dirty, 160 - 350 Pascals H10 HEPA filter pressure drop - typical clean to dirty, 250 - 600 Pascals 9.8 Pascals = 1 mm wg, & 249 Pascals = 1 inch wg
Carbon Filters Pressure Drop	Pascals	For compact type carbons pressure drop between 100 - 150 Pa Bonded carbon panels typically 150 - 170 Pa Loose granular carbon panels typically 130 Pa
Annual Operational Hours	Hrs/Annum	8760 hours in a year If operating for 5 days a week, excluding public holidays, for 12 hrs/day = 3000 hrs
Cost Of Power	Pence Per Kwh	Huge variance in what different companies pay. heck your last bill to be sure, otherwise put in 10p
Fan Efficiency	(As Decimal Value, Eg 100%=1)	Would typically be around 60%, so if you don’t have specific information use 0.6
Fan Motor Efficiency	(As Decimal Value, Eg 100%=1)	Larger motors should be around 90%, so if you don’t have specific information use 0.9

The Total Average Pressure Drop Over Your Higher Efficiency Filters And/Or Carbon Filters Is;		Pascals
This Pressure Drop Is Costing In Energy Alone	£	Per year
It Is Probable That A Sanuvox In-Duct System Could Break Down The Biological, Chemical And Odourous Contaminants On This Air Flow For Between 16 And 25% Of This Running Cost	£	Lower energy cost estimate of an equivalent Sanuvox system (16%)
	£	Higher energy cost estimate of an equivalent Sanuvox system (25%)

Type Of Building	Kw Range		BTU Range
Sports Centres
Retail Premises
Office Premises
Small Industrial Unit
Medium Industrial Units
Larger Industrial Buildings
School/Community Halls
Churches

Room/building volume	m3
Temperature differential (deltaT °C)	°C

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Cooling Glossary