ENCLOSURE COOLING - Thermal Edge
ENCLOSURECOOLINGGlossary
ContentsINTRODUCTION . 3TYPES OF COOLING EQUIPMENT . 4COOLING EQUIPMENT COMPONENTS . 5ESSENTIAL COOLING TERMS . 8COOLING EQUIPMENT ACCESSORIES . 13EQUIPMENT THAT NEEDS COOLING . 16IMPORTANT STANDARDS . 17DOCUMENTATION AND CALCULATIONS . 19NEXT STEPS . 20Enclosure Cooling Glossary
Introduction:About This GlossaryThis glossary explains some of the terms that are specifically related to enclosure cooling. Itspurpose is to extend and enhance your knowledge and understanding of enclosure coolingsystems. Hopefully this glossary will remove some of the mystery associated with the subjectand enhance interaction between the users and enclosure cooling manufacturers.The glossary is broken up into seven sections, starting with a short section about the types ofenclosure cooling equipment and followed by a section covering cooling system components.This leads to a long section that explains cooling terms and cooling accessories. The last twosections deal with engineering standards and documentation.In order to avoid confusion, items are only defined once, even though they may logically beincluded in more than one section.Enclosure Cooling Glossary3
Types of CoolingEquipmentThese are the most common types of enclosure cooling equipment.TERMDEFINITIONAir conditionerRefrigeration-based cooling system that uses the thermodynamic properties ofa refrigerant in order to extract heat from an enclosure. Key components of anair conditioner are a compressor, expansion valve, condenser, and evaporator.Air conditioners can cool enclosures to temperatures that are below ambienttemperature. The thermal capacity of standard air conditioners varies between1,000 BTU/H and 20,000 BTU/H. Typical power sources include 110, 230, and 480volts AC and 48 volts DC. Enclosure air conditioners operate on a closed-loopcooling cycle.Air to air heatexchangerThis is an enclosure cooler that works by circulating hot air from the enclosure overa heat-conductive heat pipe. This in turn discharges the heat to the outside air. Aheat exchanger uses no external power for the cooling process and is extremelyefficient. The heat exchanger relies on a thermal gradient, so its only limitation isthat it cannot cool below ambient air temperature. An air to air heat exchangeroperates on a closed-loop cooling cycle.Enclosure andair conditionerpackageFiltered fanpackageEnclosure Cooling GlossaryAn electrical enclosure supplied as a kit with an enclosure air conditioner. Theenclosure features cutouts required for a designated air conditioner model.An enclosure cooling fan designed to remove heat from an electrical enclosure. Thepackage supplied includes a fan with inlet filter and an exhaust vent with filter. Fansremove heat; they do not cool an enclosure. They draw outside air into the bottomof the enclosure and discharge it at the top. Fans operate on an open-loop coolingcycle.4
Cooling EquipmentComponentsThis section describes the major components that are used inenclosure cooling equipment and how they work.TERMDEFINITIONAir filterA device manufactured from a porous material designed to trap dust, debris and oilin the air while causing minimal airflow restriction.BlowerA mechanical device for moving air, consisting of a motor that is fitted with rotatingimpellers in a “squirrel-cage” ive compressor safeguards, including high- and low-pressure cutoutsand short-cycle protection.CondensateWater that condenses from the air as it is chilled by the air conditioner’s evaporatorcoil. Condensate must be collected and removed.CondensateevaporationsystemA method of removing the condensate collected by the air conditioner evaporator.It uses the heat from the compressor’s hot gas line in order to evaporate the water,which is then discharged as vapor to the ambient air. Condensate evaporationavoids the need for messy condensate drains and has the added benefit ofreducing the hot gas’s temperature, increasing system efficiency. This method isunique to Thermal Edge enclosure air conditioners.Condenser coilEnclosure Cooling GlossaryAn air-cooled device that is used in order to concentrate hot, pressurized refrigerantgas into a liquid. As the gas cools, it gives off heat to the ambient air.5
Cooling Equipment Components (cont.)TERMDEFINITIONCompressorA rotary, positive displacement pump used in order to compress refrigerant gas sothat it can be condensed into refrigerant liquid. Modern refrigerant compressorsincorporate many design features that increase the overall efficiency of airconditioners.DigitaltemperaturecontrollerAn electronic mechanism fitted to an enclosure air conditioner and used in order tocontrol the enclosure temperature around a user-defined set point. The controllerhas several additional functions that include high-temperature alarms, high- andlow-pressure alarms, and compressor anti-short cycle function. It is able tocommunicate with remote-control and monitoring devices using various protocols.Evaporator coilA device inside the air conditioner through which a mixture of refrigerant liquid andexpanding refrigerant vapor passes. As the liquid vaporizes, it absorbs heat, andthis cools the evaporator coil , and cooling the air going into the enclosure.Heat pipeHightemperaturealarmMountingoptionsEnclosure Cooling GlossaryThis is the heart of the air to air heat exchanger. It is a vertical tube fitted withaluminum fins in order to aid heat transfer. It is partially evacuated and filled witha suitable refrigerant. The refrigerant is chosen so that it boils when hot air fromthe enclosure is passed over it. As the refrigerant boils, it absorbs heat from theenclosure. The refrigerant vapor rises to the top of the pipe, where it is cooled byambient air that is blown over the tube. This vapor condenses back into liquid,giving up its heat to the ambient air.An adjustable alert mechanism connected to a set of dry contacts actuated by thedigital controller that provides a warning if the enclosure temperature goes too high.Enclosure air conditioners and air to air heat exchangers are primarily designedto be mounted on either side of an electrical enclosure. Optionally, they can bemounted on the enclosure door, provided it is strong enough and the enclosureis anchored down. Air conditioners are also available to mount on the top of anelectrical enclosure.6
Cooling Equipment Components (cont.)TERMPower cordDEFINITIONPower supply wiring connected to enclosure coolers and fans that is fitted with asuitable plug.Power switchAn on/off power control fitted to enclosure coolers to energize the unit.Refrigerant: A substance that absorbs heat in order to form a vapor. Whencompressed, it condenses and gives up that heat.Rigid chassisAir conditioners and air to air heat exchangers with a rigid chassis provide theability to be serviced without being removed from an electrical enclosure.Sloped topThe top surface of air conditioner shrouds is sloped in order to allow easy waterrunoff.ThermalexpansionvalveA special flow controller that regulates the circulation of refrigerant liquid to the airconditioner evaporator. It operates by sensing the temperature of the refrigerantas it expands, and this allows it to control the flow of refrigerant in order to suit theheat load. A thermal expansion valve is the most efficient method of controlling theexpansion of a refrigerant and can tolerate a wide heat load range.Enclosure Cooling Glossary7
EssentialCooling TermsThis list comprises commonly used terms related to enclosure cooling.TERMACAmbienttemperatureBackup powerBTU/HCapillary tubeCFMClosed-loopcoolingEnclosure Cooling GlossaryDEFINITIONAlternating electric current.The temperature of the outside air around an enclosure.Battery-operated backup power often used to provide power totelecommunications equipment during power outages.A unit of measurement of thermal energy known as British Thermal Units per Hour.One BTU/H is equivalent to 0.29 watts.A long, small-diameter copper pipe used in order to control the expansion of arefrigerant. It performs the same function as a thermal expansion valve, althoughit is calibrated for only one temperature. It’s commonly used on domesticrefrigerators.An abbreviation for Cubic Feet per Minute; it’s used as a measure of the flow of air.A term used in order to describe a cooling solution in which the enclosure iscompletely sealed, preventing the entry of outside air. This stops contaminants fromentering the enclosure and is the only practical method for cooling enclosures byenclosure air conditioning, because it avoids the uncontrolled flow of hot outside airinto the enclosure.8
Essential Cooling Terms (cont.)TERMDEFINITIONCompressorprotectionA self-resetting thermal overload switch mounted to a refrigeration compressor.ConductionThe transfer of heat through a solid object.ConvectionThe transfer of heat energy using a fluid such as air or water.CoolingcapacityDCDehumidificationDew pointDirt and dustThe thermal cooling ability of an enclosure cooler measured in BTU/H or in watts.Direct electric current.The removal of water vapor from the air, usually achieved by cooling the air to atemperature below the dew point, causing the moisture to condense.The temperature at which water vapor in the air will condense. The dew-pointtemperature is directly related to the relative humidity of the air.Small particles in the air composed of earth, soil, or waste matter.EfficiencyThe ratio between the input power to a machine or electronic device and the usableoutput power.ElectricalenclosureA special cabinet that has been designed for the installation of electrical controlgear and that complies with certain safety standards.Enclosure Cooling Glossary9
Essential Cooling Terms sFan-cooledHeat loadDEFINITIONThe measure of warmth or coldness of the air inside an enclosure.The condition of the air around an enclosure, including its temperature and relativehumidity as well as the amount of dirt and dust particles in the air. The term alsoencompasses exposure to the sun and the presence of corrosive substances, rain,and snow.Equipment cooled by the forced circulation of air using a fan.The amount of heat generated by the equipment inside an enclosure.Heat transferThe exchange of thermal energy between physical systems.High altitudeThe effectiveness of an air conditioner decreases with altitude in direct proportionto the density of air. At 3,000 feet, the capacity of an air conditioner is reduced by10 percent.Hot gas lineThe refrigerant tubing that carries hot, compressed gas away from the compressor.Hot spotsAreas within an electrical enclosure that are hotter than others due to poor airflowor local sources of heat.InsulatedenclosureAn enclosure fitted with thermal lining material that reduces heat transfer throughthe walls on the enclosure.Latent heatEnclosure Cooling GlossaryThe energy required in order to change the state of a substance, such as the energyrequired to convert water at 212 F into steam without changing its temperature.10
Essential Cooling Terms (cont.)TERMDEFINITIONMaximumambienttemperatureThe highest temperature that has been recorded for a particular location.MinimumambienttemperatureThe lowest temperature that has been recorded for a particular location.NaturalventilationThe natural flow of air through an enclosure, aided by the natural tendency of hot airto rise.Open-loopcoolingA cooling solution that draws cooler outside air into an enclosure in order to coolequipment. It is the opposite of closed-loop cooling.PowerThe rate at which energy is released or used. It is measured in horsepower or watts.One horsepower is equal to 746 watts.RadiationThe transfer of heat energy through electromagnetic rays. The heating effect of thesun is an example of radiation.RefrigerationcycleA closed cycle of the evaporation, compression, and condensation of a refrigerantthat transfers heat from one place to another.RelativehumidityThe amount of water vapor present in the air compared to the maximum amount ofwater that the air can hold at that temperature.Solar heat loadEnclosure Cooling GlossaryThe heating effect of the sun’s radiation on an enclosure.11
Essential Cooling Terms (cont.)TERMTelecomenclosureDEFINITIONA special cabinet that houses telecommunications equipment.TemperatureThe measurement of heat energy in a body or substance. It is usually measured indegrees Fahrenheit, although the metric measures of centigrade and Celsius arealso common.TemperaturecontrolThe use of a controller in order to regulate the temperature of an enclosure arounda set temperature.ThermostatVentilatedWatts per FEnclosure Cooling GlossaryA device used in order to regulate temperature by opening or closing a switch asthe temperature around the sensor changes.Equipment that is cooled by the flow of external air through the enclosure.A measure of the cooling capacity of an air to air heat exchanger that providesinformation on the amount of heat in watts that will be removed for each degreeFahrenheit of difference between the enclosure temperature and the outsideambient temperature. This term can also be stated as watts per C.12
Cooling EquipmentAccessoriesThis section covers those items that are generally available as optional accessories.TERMDEFINITIONAlarm andControllingWeb serverA Web server that provides the facility to monitor and control enclosure airconditioners remotely using the Internet or an intranet. Can also be used with PLCs.CorrosiveenvironmentpackagesA range of packages providing differing levels of corrosion protection to airconditioner coils and piping through the use of protective epoxy coatings.Dry contactalarmAn optional set of contacts for providing a high-temperature alarm.Filter, 2-inchA heavy-duty, high-capacity, washable filter fitted in a 2-inch-deep frame for verydusty conditions.HazardouslocationAir conditioners and air to air heat exchangers can be supplied for use withenclosures installed in the presence of explosive materials. The most commonrating is for Class 1, Division 2, Groups B, C, and D hazardous locations.HeaterpackageAn optional integrated heater package can be specified with air conditioners inorder to prevent the enclosure temperature dropping too low when the ambienttemperature declines.Enclosure Cooling Glossary13
Cooling Equipment Accessories (cont.)TERMDEFINITIONHigh ambientoptionThis option provides improved performance for air conditioners used in highambient temperatures, including temperatures as high as 140 F.Louveredsecurity coverA tamperproof filter cover.Low ambientoptionAn option designed to assist compressor-starting in very cold weather by keepingthe compressor oil warm.NEMAenclosuresAir conditioners and air to air heat exchangers can be supplied for use with NEMAType 12, 4, and 4X enclosures suited for indoor or outdoor operation in harshconditions.Open-door killswitchThis optional switch turns off the air conditioner when the enclosure doors areopened in order to prevent formation of excessive condensate.3R shroudA NEMA Type 3R fan shroud kit designed to prevent water ingress with outdoorenclosures using filtered fan packages.RedundantsystemDesigned for critical applications where 100 percent redundancy is required.It controls two air conditioners with provision for automatically cycling each airconditioner periodically.RemotecontrollerStainless steelhousingEnclosure Cooling GlossaryAn option to install the digital controller inside the electrical enclosure.All air conditioners and air to air heat exchangers can be supplied with an optionalstainless steel housing with grained and polished finish.14
Cooling Equipment Accessories (cont.)TERMTemperatureprobe,adjustableDEFINITIONA temperature probe that is attached to a 12 foot cable so it can be installed in theenclosure in order to allow the digital controller to control the temperature at anylocation inside the enclosure.Universalmounting plateThis is used when replacing or upgrading an enclosure air conditioner that hasdifferent enclosure openings.VibrationpackageA vibration protection package is available for air conditioners to be mounted inlocations subject to excessive vibration.Enclosure Cooling Glossary15
Equipment ThatNeeds CoolingThis section lists the most typical applications for enclosure cooling.TERMDEFINITIONControlcabinetsIndustrial and other control cabinets are often located in hot and dustyenvironments. These cabinets are usually sealed in order to prevent the ingress ofdirt and dust.Industrial andutility electricalenclosuresMost electrical enclosures will benefit from enclosure cooling, especially becauseof the widespread use of electronically controlled electrical equipment.PLC andSCADAsystemsIntegrated control systems using PLCs and SCADA systems are common. In aproduction environment, downtime can cause widespread disruption. Althoughthese systems are robust, their processors and memory chips should not beallowed to exceed recommended operating temperatures, and it is good practice toemploy closed-loop cooling solutions.StandbybatteriesThe service life of a standby battery system using lead acid batteries is adverselyaffected if ambient temperatures exceed 75 F. Standby battery installations shouldbe cooled in order to avoid premature battery failure.TelecomequipmentTelecom equipment is often installed outdoors and subject to solar radiation.Because the Telcordia GR-3108-CORE Class 1 requirements specify a maximumenclosure temperature of 104 F, most telecom cabinets need enclosure cooling.Variablefrequencydrives andinvertersPowerful variable-frequency drives and inverters generate a significant amountof waste heat. Additionally, these devices should not be allowed to exceed theirmaximum operating temperatures or they may suffer damage. In most instances,some form of enclosure cooling is recommended.Enclosure Cooling Glossary16
ImportantStandardsHere is a brief list of some of the more important local andinternational standards relating to enclosure cooling systems.TERMCECSADEFINITIONThis mark specifies that equipment complies with European health and safetyrequirements. It is not applicable in the U.S.Canadian Standard Association that is responsible for the Canadian electrical codeto which enclosure cooling systems for sale in Canada must comply.IP RatingThe European ingress protection code used internationally. Although similar toNEMA enclosure protection standards, it is not always directly comparable.NECThe National Electrical Code issued by the National Fire Protection Association.NEMAThe National Electrical Manufacturers Association, which is responsible for theNEMA enclosure protection standards.NRTLA Nationally Recognized Testing Laboratory.OSHAThe U.S. Occupational Safety and Health Administration.Enclosure Cooling Glossary17
Important Standards (cont.)TERMTelcordiaspecificationsULEnclosure Cooling GlossaryDEFINITIONTelecom standards issued by Telcordia that have wide acceptance. These includethe GR-487-CORE requirements for electronic equipment cabinets and the GR3108-CORE equipment testing requirements.Previously known as Underwriters Laboratory, an NRTL laboratory that testsequipment to U.S. (UL) and Canadian (cUL) standards. All Thermal Edge equipmentis tested to UL standards.18
Documentationand CalculationsThis section deals specifically with Thermal Edge documentation.TERMETMCalculator1Product sheetsDEFINITIONAn online enclosure temperature management calculator that can be used in orderto calculate enclosure cooling requirements.Data sheets providing detailed technical specifications for an individual coolingsolution or for a range of cooling equipment.User andtechnicalmanualThe detailed user manual supplied with each enclosure cooling product.WarrantyThe Thermal Edge warranty statement: All products are warrantied for one yearfrom date of purchase.Enclosure Cooling Glossary19
NEXT STEPSThe purpose of this glossary is to help designers, customers, and anyone elseinvolved with enclosure cooling understand the various terms used and specificallyto understand how these apply to Thermal Edge products. Although the glossarycovers terms commonly used, it is not possible to cover everything in completedetail.All Thermal Edge products are designed with great care and built to exactingstandards in order to ensure reliable operation in the field. Our Sales Team2and Technical Support Team3 are always available to provide practical help andguidance to help you select the best cooling system for your application or toprovide you with additional information.SOURCES1. Thermal Edge: ETM Calculator2. Thermal Edge: Sales Team3. Thermal Edge: Support TeamUSE THE ETM CALCULATOR 2016 Thermal Edge, Inc. 888.580.0202
and enhance interaction between the users and enclosure cooling manufacturers. The glossary is broken up into seven sections, starting with a short section about the types of enclosure cooling equipment and followed by a section covering cooling system components. This leads to a long section that explains cooling terms and cooling accessories.
and enhance interaction between the users and enclosure cooling manufacturers. The glossary is broken up into seven sections, starting with a short section about the types of enclosure cooling equipment and followed by a section covering cooling system components. This leads to a long section that explains cooling terms and cooling accessories.
McLean Electronics Cooling: Sealed Enclosure Cooling Air Conditioners Spec-00732 B Spec-00732BPH (FX (McLean Electronics Cooling Sealed Enclosure Cooling Air Conditioners SPECTRACOOL Narrow Indoor/Outdoor N43 11000 BTU/Hr. 3223 Watt N36 6000/8000 BTU/Hr. 1758/2344 Watt N28 4000 BTU/Hr. 1172 Watt Industry Standards
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Developers have moved to green cooling technique to save energy in unique way. Besides air cooling, evaporative water cooling, oil immersion cooling has gained rapid acceptance in data center cooling area. [1]. Evaporative cooling has been taking place over air-cooling system because of the cooling
COOLING SOLUTIONS the integration of Hoffman enclosures and cooling offers best-of-class performance and protection. advanced cooling products designed to complement our offering of standard enclosures thermal load pre-calculation to provide optimum cooling options for components, enclosure package, and environment
cubic feet we have, and the enclosure is now 1.79 cubic feet. Since the recommended sealed enclosure for the Punch Power 12" DVC subwoofer is 1.25 cubic feet to 1.75 cubic feet, we're just about right on with the enclosure! However, if we were trying to make a ported enclosure that was 2.0 cubic feet, we'll need to make the enclosure
data for building enclosure assemblies using Owens Corning insulation and systems, and provides example U-value calculations for the entire opaque building enclosure. INTRODUCTION Thermal bridges are localized areas of significantly higher heat flow through walls, roofs, and other insulated building enclosure components than the surrounding .
ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959. . Second Revision No. 2-NFPA 501-2016 [ Section No. D.1.2.2 ] D.1.2.2ASTM PublicationPublications. ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959. ASTM E903, Standard Test Method for Solar Absorptance, Reflectance, and Transmittance of Materials Using .
