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Terminology and Resources

Fan and Blower Related Associations

Air Movement and Control Association (AMCA) International, Inc.
http://www.amca.org
Phone: 847-394-0150
Provides information on air systems and equipment, including industrial fans, and provides a Certified Ratings Program for equipment.

Home Ventilation Institute (HVI)

http://www.hvi.org
Phone: 847-526-2010
Represents manufacturers and distributors of industrial fans, blowers and related equipment.

American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE)
http://www.ashrae.org
Phone: 800-527-4723
Professional organization providing information on ventilation, heating, refrigerating and air-conditioning systems

Fan and Blower Resource Magazines

HVACR News
http://www.hvacrnews.com

ACH & R News
http://www.achrnews.com

Fan / Blower Terms & More

Air Changes or Exchanges - The amount of time, expressed in minutes, that is takes for a fan system to replace air in an area.

Air Distribution - The delivery of outdoor or conditioned air to various spaces in a building, usually by mechanical means.

Air Velocity - The rate and direction of air movement.

Amperage -  The ampere or amp (Symbol: A) is the standard unit of electric current. An electric current of one amp is one coulomb per second. ... One amp is defined as the current producing an attractive force of 2×107 newtons per metre of length between these wires.

CFM - Abbreviation for cubic feet per minute; a measurement of the amount of air a fan or blower moves through ventilation and circulation during operation.

Circulation - The process of a fan moving air around within a specific area.

Cross Ventilation - Air that enters on one side of a room and leaves on a different side of the same room.

Damper or Shutter - The mechanism responsible for the regulation of airflow in a fan system; dampers consist of inlet dampers, which regulate airflow into the system, and outlet dampers, which control air movement out of the system.

Fan Blade - The fan component extending from the hub that rotates, cutting into the air and producing air movement. Fan blades may stick straight out in a radial position, curve forward in the direction of fan wheel rotation or curve backward.

Fan Drive - The fan mechanism responsible for controlling the movement of the fan wheel, including fan wheel speed.

Fan Wheel - Fan component consisting of a hub and blades, which rotate about the wheel in order to produce air movement.

FPM - Abbreviation for feet per minute.

Hub - The point on an industrial fan wheel from which the fan blades extend.

Multizone - A building or part of a building that comprises a number of zones or cells.

Static Pressure - The amount of resistance in a circulation or ventilation system that a fan must surmount to ensure proper air movement.

Total Pressure - The total amount of pressure, measured in Pascals, that an industrial fan or blower produces, including both the static pressure and the velocity pressure.

Velocity - The rapidity of air movement in a ventilation system, measured in feet per minute (fpm).

Velocity Pressure - The amount of pressure in a circulation or ventilation system resulting from air movement.

Ventilation - The fan process in which air is moved into, out of and between different areas. Ventilation is used to replace old, stale, odiferous or contaminated air with fresher, cleaner air.

Heater Related Associations

Industrial Heating Equipment Association (IHEA)
http://www.ihea.org
Phone: 513-231-5613
Enhances member company capabilities to serve end users in the industrial heat processing industry.

National Electrical Manufacturers Association (NEMA)
http://www.nema.org
Phone: 703-840-3200
A forum for the standardization of electrical equipment.

International Thermoelectric Society (ITS)
http://www.its.org
Dedicated to the advancement of thermoelectric industry, science and technology.

International Organization for Standardization (ISO)
http://www.iso.ch/iso/en/ISOOnline.frontpage
Phone: +41 22 749 01 11
A network of the national standards institutes from 148 countries.

Heater Resource Magazines

Industrial Heating
http://www.industrialheating.com

Process Heating
http://www.process-heating.com

HPAC Engineering
http://www.hpac.com

Other

"Guide For Heat Losses"
http://www.hotwatt.com/heatloss.htm

"Cartridge/Superwatt Heaters"
http://www.hotwatt.com/installa.htm

Heater Terms

Amps - The meter-kilogram-second unit of electric current that is equivalent to the steady current produced by one volt applied across a resistance of one ohm.

British Thermal Unit (BTU) - Used for measuring a quantity of heat. One BTU is the quantity of heat necessary to raise the temperature of 1 pound of water 1°F.

Celsius - The metric temperature scale in which water freezes at zero degrees and boils at 100 degrees, designated by the symbol "C".

Circuit - An electrical device providing a trail for electrical current to flow.

Duct - An enclosure in which air is moved that is primarily constructed from sheet metal.

Fahrenheit - The heat scale on which water freezes at 32 degrees and boils at 212 degrees, abbreviated by the letter F.

Fan - A device that creates currents of air, sometimes built in electric heaters to push air out from the unit.

Heating Coil - Any coiled element that serves as the source of heat.

Heating Element - The component of the heater which is responsible for conducting the heat.

Hertz - In alternating current (AC electricity), the number of cycles per second, denoted hz.

Kilowatt - A measure of 1,000 watts of electrical power.

IP or Ingress Protection (see chart below) - This is the sealing effectiveness of electrical enclosures including mechanical controls and electrical motors.

Peltier Modules - Jean Peltier in 1834, discovered that passing an electric current through the junction of two different conductors cools or heats the junction depending on the direction of the current. The modern Peltier modules are made out of semiconductor material, and are used in thermoelectric devices.

Radiationange - The distribution of energy by electromagnetic waves, of a generally long wave-length.

Sensor - Any device that reacts to a change in the environment being measured, by signaling of the change via audible or visual means.

Therm - A measurement of heat equal to 100,000 btu.

Thermocouple - Measures the difference in potential created at the junction of two different metal wires, which feed from the measuring instrument. (http://www.thermocouple-assemblies.com)

Thermostat - An automated device for controlling temperature.

Thyristor - A power semiconductor device with three terminals called the gate, cathode and anode. Its state becomes conductive (ON) or blocking (OFF) depending on the behavior of these terminals.

Volts - The difference of possibility between two points in a conducting wire with a constant current of one ampere.

Watts - The SI unit of power, equivalent to one joule per second, corresponding to the power in an electric circuit in which the potential difference is one volt and the current one ampere.

Enclosure Ratings & Standards Explained

What is an IP or Ingress Protection Rating ?

IP rating is also known as Ingress Protection or International Protection ratings which are defined to the international standard of EN 60529 (British BS EN 60529:1992). This standard is used to define the levels of sealing effectiveness of electrical enclosures against intrusion from foreign bodies such as tools, dirt and moisture.  

What do the two digits in an IP Rating mean?

The rating consists of the letters IP followed by two digits, if a number is replaced by X this indicates that the enclosure is not rated for that specification. 

IP65   =  First Digit - Solids

The first digit indicates the level of protection that the enclosure provides against access to hazardous parts (electrical conductors, moving parts etc) and the ingress of solid foreign objects.

IP65   =  Second Digit - Liquids

The second digit defines the protection of the equipment inside the enclosure against various forms of moisture (drips, sprays, submersion etc).

First Digit Intrusion Protection Second Digit Moisture Protection
0 No protection. 0 No protection.
1 Protected against solid objects over 50mm, e.g. accidental touch by hands. 1 Protected against vertically falling drops of water, e.g. condensation.
2 Protected against solid objects over 12mm, e.g. fingers. 2 Protected against direct sprays of water up to 150 from the vertical.
3 Protected against solid objects over 2.5mm, e.g. tools & wires. 3 Protected against direct sprays of water up to 600 from the vertical.
4 Protected against solid objects over 1mm, e.g. wires & nails. 4 Protected against water splashed from all directions, limited ingress permitted.
5 Protected against dust limited ingress, no harmful deposits. 5 Protected against low pressure jets of water from all directions, limited ingress permitted.
6 Totally protected against dust. 6 Protected against strong jets of water, e.g. on ships deck, limited ingress permitted.

 


Below is an easy to follow chart to help you decide which IP rating / IP codes you may require for your electrical enclosure.

IP Rating Reference Chart

IP Rating First Digit - SOLIDS Second Digit - LIQUIDS
IP00 Not protected from solids. Not protected from liquids.
IP01 Not protected from solids. Protected from condensation.
IP02 Not protected from solids. Protected from water spray less than 15 degrees from vertical.
IP03 Not protected from solids. Protected from water spray less than 60 degrees from vertical.
IP04 Not protected from solids. Protected from water spray from any direction.
IP05 Not protected from solids. Protected from low pressure water jets from any direction.
IP06 Not protected from solids. Protected from high pressure water jets from any direction.
IP07 Not protected from solids. Protected from immersion between 15 centimetres and 1 metre in depth.
IP08 Not protected from solids. Protected from long term immersion up to a specified pressure.
IP10 Protected from touch by hands greater than 50 millimetres. Not protected from liquids.
IP11 Protected from touch by hands greater than 50 millimetres. Protected from condensation.
IP12 Protected from touch by hands greater than 50 millimetres. Protected from water spray less than 15 degrees from vertical.
IP13 Protected from touch by hands greater than 50 millimetres. Protected from water spray less than 60 degrees from vertical.
IP14 Protected from touch by hands greater than 50 millimetres. Protected from water spray from any direction.
IP15 Protected from touch by hands greater than 50 millimetres. Protected from low pressure water jets from any direction.
IP16 Protected from touch by hands greater than 50 millimetres. Protected from high pressure water jets from any direction.
IP17 Protected from touch by hands greater than 50 millimetres. Protected from immersion between 15 centimetres and 1 metre in depth.
IP18 Protected from touch by hands greater than 50 millimetres. Protected from long term immersion up to a specified pressure.
IP20 Protected from touch by fingers and objects greater than 12 millimetres. Not protected from liquids.
IP21 Protected from touch by fingers and objects greater than 12 millimetres. Protected from condensation.
IP22 Protected from touch by fingers and objects greater than 12 millimetres. Protected from water spray less than 15 degrees from vertical.
IP23 Protected from touch by fingers and objects greater than 12 millimetres. Protected from water spray less than 60 degrees from vertical.
IP24 Protected from touch by fingers and objects greater than 12 millimetres. Protected from water spray from any direction.
IP25 Protected from touch by fingers and objects greater than 12 millimetres. Protected from low pressure water jets from any direction.
IP26 Protected from touch by fingers and objects greater than 12 millimetres. Protected from high pressure water jets from any direction.
IP27 Protected from touch by fingers and objects greater than 12 millimetres. Protected from immersion between 15 centimetres and 1 metre in depth.
IP28 Protected from touch by fingers and objects greater than 12 millimetres. Protected from long term immersion up to a specified pressure.
IP30 Protected from tools and wires greater than 2.5 millimetres. Not protected from liquids.
IP31 Protected from tools and wires greater than 2.5 millimetres. Protected from condensation.
IP32 Protected from tools and wires greater than 2.5 millimetres. Protected from water spray less than 15 degrees from vertical.
IP33 Protected from tools and wires greater than 2.5 millimetres. Protected from water spray less than 60 degrees from vertical.
IP34 Protected from tools and wires greater than 2.5 millimetres. Protected from water spray from any direction.
IP35 Protected from tools and wires greater than 2.5 millimetres. Protected from low pressure water jets from any direction.
IP36 Protected from tools and wires greater than 2.5 millimetres. Protected from high pressure water jets from any direction.
IP37 Protected from tools and wires greater than 2.5 millimetres. Protected from immersion between 15 centimetres and 1 metre in depth.
IP38 Protected from tools and wires greater than 2.5 millimetres. Protected from long term immersion up to a specified pressure.
IP40 Protected from tools and small wires greater than 1 millimetre. Not protected from liquids.
IP41 Protected from tools and small wires greater than 1 millimetre. Protected from condensation.
IP42 Protected from tools and small wires greater than 1 millimetre. Protected from water spray less than 15 degrees from vertical. 
IP43 Protected from tools and small wires greater than 1 millimetre. Protected from water spray less than 60 degrees from vertical.
IP44 Protected from tools and small wires greater than 1 millimetre. Protected from water spray from any direction.
IP45 Protected from tools and small wires greater than 1 millimetre. Protected from low pressure water jets in any direction.
IP46 Protected from tools and small wires greater than 1 millimetre. Protected from high pressure water jets from any direction.
IP47 Protected from tools and small wires greater than 1 millimetre. Protected from immersion between 15 centimetres and 1 metre in depth.
IP48 Protected from tools and small wires greater than 1 millimetre. Protected from long term immersion up to a specified pressure.
IP50 Protected from limited dust ingress.   Not protected from liquids.
IP51 Protected from limited dust ingress.    Protected from condensation.
IP52 Protected from limited dust ingress. Protected from water spray less than 15 degrees from vertical.
IP53 Protected from limited dust ingress. Protected from water spray less than 60 degrees from vertical.
IP54 Protected from limited dust ingress. Protected from water spray from any direction.
IP55 Protected from limited dust ingress. Protected from low pressure water jets from any direction.
IP56 Protected from limited dust ingress. Protected from high pressure water jets from any direction.
IP57 Protected from limited dust ingress. Protected from immersion between 15 centimetres and 1 metre in depth.
IP58 Protected from limited dust ingress. Protected from long term immersion up to a specified pressure.
IP60 Protected from total dust ingress. Not protected from liquids.
IP61 Protected from total dust ingress.                          Protected from condensation.
IP62 Protected from total dust ingress. Protected from water spray less than 15 degrees from vertical.
IP63 Protected from total dust ingress. Protected from water spray less than 60 degrees from vertical.
IP64 Protected from total dust ingress. Protected from water spray from any direction.
IP65 Protected from total dust ingress. Protected from low pressure water jets from any direction.
IP66 Protected from total dust ingress. Protected from high pressure water jets from any direction.
IP67 Protected from total dust ingress. Protected from immersion between 15 centimetres and 1 metre in depth.
IP68 Protected from total dust ingress. Protected from long term immersion up to a specified pressure.
IP69K Protected from total dust ingress. Protected from steam-jet cl