Environmental and Safety Management Manual Thermal Management, Environmentally Controlled Cabinet Outdoor Cabinet for Communications Microwave Radio Equipment and Traffic control products, Weatherproof Aluminum Cabinet Enclosures, Outdoor cabinets, Weatherproof Nema Rated Outdoor Cabinet Enclosure, Traffic Control, Video Detection, Controller Cabinets, Traffic Equipment, Traffic Signals, Light Emitting Diodes, Strobe Lighting, Loop Monitors, Wireless communications, Pedestrian Signal, NEMA Traffic Controllers, Monivision, Inductive Loop Detector, Loadswitch, Solid State Flasher, Flow Monitoring, Data Acquisition, Incident Monitoring, traffic Supply, Wireless.
Clean, Renewable Energy – A Clear Investment for the Future

 

Help

Click Here! To Search for prices and Order Online our products database

Get A Quote

Order Online
  -Request Pricing
  -View Our Clients
 How we Work
 How to Get a Quotation

  -Contact Us
  -View My Invoice

 


  -Export Information
  -�Hablamos Espa�ol!
  -Buy Online

Aviation Products
  -Airfield Lighting
  -Airfield Accessories
  -Airport Your Speed Traffic Signs
  -Airport 24 Hour Flashing Beacons
  -Airport 24 Hour Flashing Beacon
  -Airport Lighting Controls
  -Airport Video Surveillance
  -Approach Lighting Systems
  -Airport Elevated Runway Lights
  -Crane Obstruction Lights
  -Elevated Runway Guard Lights
  -Obstruction Lighting
  -Runway & Taxiway Elevated Lights
  -Runway & Taxiway Inserts Lights
  -Solar Aviation Lights
  -Solar Beacons Lights
  -Solar Crane Lights
  -Solar Helipad Lights
  -Solar Obstruction Lights
  -Solar Perimeter Lights
  -Solar RunWay Lights
  -Solar RunWay EDGE Lighting
  -Solar TaxiWay Lights
  -Solar TAXIWAY Lighting
  -Solar Threshold Lights
  -Solar PAPI Lights
  -Solar Tower Lights
  -Solar Wind Cones
  -Solar Airport UPS Backup Energy
Automation
  -Data Acquisition
  -Motion Sensors
  -SCADA
  -Software
  -Solar Power Generator
Catalog
  -Catalogs in PDF
Communications
  -Wireless Airfield Light Control
  -Wireless Control
  -Wireless Lighting Control
Components
  -Batteries
  -Enclosures
  -Enclosures Air Conditioners
  -Enclosures Thermal Management
Computers
  -Apps
  -Coud Services
  -Computer Solar Backups
  -Commercial Building Automation
  -Computer Solar Chargers
Electronics
  -Battery Chargers
  -DC to DC Converters
  -Din Rail Power Supply
  -Electrical Vehicles
  -Electrical Vehicle Charging
  -OEM
  -Power Supplies
  -Timers
Enclosures
  -Battery Enclosure
  -LTE enclosure 4G Enclosure
  -Outdoor enclosures Single Bay
  -Outdoor Enclosure Double Bay
  -Outdoor enclosure Triple Bay
  -Traffic enclosures
Energy Solutions
  -Battery Backup Storage
  -Energy Storage
  -Fuel Cells
  -Hospital Emergency
  -Hospital Fuel Cells UPS
  -Hospital Signals
  -Landfills Green Energy Generator
  -Modular Power Storage
  -Pipeline Oil and Gas
  -Portable Solar Power Generator
  -Solar Powered SCADA
  -Security and Surveillance
  -Solar EV Charge Station
  -Solar Trailers
  -Solar Trees
  -Telecom Power Supplies
  -Traffic Management
Government
  -Foldable Solar Battery Charger
  -Fuel Cells Military
  -GSA Government
  -Homeland Security
  -Military Bases Your Speed Signs
  -Military Solar Gate Openers
  -Military Secure Fence Lighting
  -Military Video Surveillance
  -Portable Military Solar Power
Hospital
  -Hospital Emergency Back-Up Power
  -Hospital Signals
  -Hospital Solar 24 Flashing Beacons
  -Hospital Solar Parking Lot Lighting
  -Hospital Solar Powered Speed Radar
  -Hospital Solar Video Surveillance
  -Medical Grade UPS
  -Medical Grade Fuel Cells Backup
  -Inverters Ambulance EMS
  -Vaccine Refrigerators Solar
Lighting
  -Arms
  -Billboards LED Lighting
  -Bridge Solar LED Lighting
  -Bus Stop Shelter Solar Light
  -Bullet Proof Solar LED Lights
  -Explosion Proof Lights
  -Explosion Proof Rotating Lights
  -LED Street Lights
  -Perimeter Security Lighting
  -Poles
  -Solar LED Lighting
  -Solar Street Lighting
  -Solar LED Street Lighting
  -Solar Parking-Lot Lighting
  -Solar Light Tower
  -Solar Security Lighting
  -School Parking lot Lighting
  -Solar Powered Parking Lot Light
  -Tunnel Lighting
Marine
  -Marine Navigation Lights
  -Port Entry Lights
  -Solar Marine Lighting
  -Solar Marine Navegation Lights
  -Marine Navigation Lights
Military Sytems
  -Military Bases Solar Lighting
  -Military Energy Storage
  -Military Traffic Safety
  -Military Video Surveillance
  -Military Video Surveillance Solar
  -Military Solar Light Tower
  -Military Bases Your Speed Signs
  -Military Portable Solar Power
  -Military Solar Enery Trailer
Obstruction Lights
  -Obstruction Lights FAA
  -Obstruction Lights ICAO
  -Obstruction Lighting
  -Solar Obstruction Lighting
  -Solar Obstruction Lighting FAA
  -Solar Obstruction Lighting ICAO
Power Sytems
  -Battery Chargers
  -DC to DC Converters
  -DC to DC Converters Din Rail
  -Din Rail Uninterruptible Power Supply
  -Inverters Accessories
  -Inverters Battery Based Off Grid
  -Inverters Grid-Tied
Projects
  -Battery Storage Smart Grid
  -Commercial- Industrial
  -Military Modular Energy Storage
  -Mobile Solar Power
  -Electrical Vehicle Charging Station
Security
  -Ballistic Protection
  -Cameras
  -Cameras Enclosures
  -Defense And Security Solutions
  -Gate Openers
  -Gate Openers Solar Powered
  -Industrial Video Surveillance
  -Infra Red Illuminators
  -Metal Weapons Detectors
  -Radar Your Speed Sign
  -Solar-Powered Security Lights
Solar Energy Components
  -Charge Controllers
  -Inverters Accessories
  -Inverters Battery Based Off Grid
  -Inverters Grid-Tied
  -Portable Battery Charger
  -Solar Modules
  -Solar Modules Ballistic Protection
  -Mounting Structures
Solar Systems
  -Cathodic Protection
  -Disaster Relief Vehicle
  -Commercial Solar Power
  -Home Solar Power System Grid Tie
  -Home Solar Power System Off Grid
  -Portable Solar Generator
  -Remote Solar Power Supply AC
  -Remote Solar Power Supply DC
  -Solar Powered Parking Lots
Traffic
  -Accessories
  -Battery Backup
  -24/7 Traffic Flashing Beacons
  -LED Traffic Signals
  -Portable Traffic Signals
  -Railroad
  -Railroad Crossing Signals Backup
  -Remote Controlled Signals
  -Solar Powered Traffic Lights
  -Solar Powered Your Speed Signs
  -Solar School Zone Flashing Beacons
  -Solar School Parking Lot Lighting
  -Solar Traffic Lights
  -Traffic Controls
  -Traffic
  -Traffic 24 Hour Solar Flashing Beacon
  -Traffic Solar School Zone Beacons
  -Traffic Your Speed
  -Traffic Parts
  -Traffic Lights
  -Traffic Signal Battery Backup
  -Your Speed Signs Solar Powered
UPS Backup Systems
  -UPS Airport Generators
  -Base Station for Moville Networks
  -UPS Data Center Facilities
  -UPS Emergency Generators
  -UPS Hospital Generators
  -UPS Traffic Generators
  -UPS Fuel Cell Generators
Visual Signals
  -Explosion Proof Rotating Beacons
  -Marine Solar Powered Beacons
  -Solar Marine & Dock Lighting
  -Rotating Beacons
  -Solar Powered Beacons
Water Treatment
  -Solar Powered for Water Treatment
  -Solar Water Pumps Accessories
  -Solar Powered Water Pumps
  -Video Surveillance for Water Treatment Plants
  -Water Pumps
Wind Generators
  -Wind Turbines Accessories
  -Wind Turbines
  -Wind Turbine Obstruction Lighting
  -Wind Turbine Lighting



  -Become Partner
  -Export How To
  -�Hablamos Espa�ol!
  Our Blog | News | Our App


Credit Card Transactions Secured by!

Click Here for Catalog in PDF format!
Click to Access our Catalog in PDF


Browse our product catalog, submit requests for quotation and stay up to date with product news, specials and environmental news.


Our Blog is managed with Milk-App.com A Tumblr Client for the Mac

A Tumblr Client for the Mac, Everything you love about Tumblr, from the comfort of your desktop.



Bellebnb Hotel Cloud Booking Management.
Booking Engine
Front Desk
Payment Gateway
Channel Management
Hotel Concierge App

Bellebnb Hotel Cloud Booking Management
Hotel Buchung Motor
Cloud Buchung Engine
Motor de Reservas
Hotel Booking Engine
Motore di Prenotazione



IQLED.com
IQAirport.com
IQTraffiControl.com
IQSolarLighting.com
IQUPS.com


© - OkSolar.com ()

- v7.77

Tatami Software

 
Electrical Enclosure Cooling With Special Purpose Air Conditioners
 
Environmentally Controlled enclosures and Cabinet weatherproof Aluminum Cabinet Enclosures,
 Environmentally Controlled Cabinet Outdoor Cabinet for Communications Microwave Radio Equipment and Traffic control products

 

 

Enclosures:

Enclosures Quality, Environmental and Safety Management Manual Thermal Management.

 

 

Heat producing power and control components are being packaged in less space, increasing the power densities in electronic and industrial equipment enclosures. Computers, programmable logic controllers, microprocessors, variable speed drives, power conversion and storage devices have found their way into every industrial and commercial environment.

The problem of dissipating the heat generated to prevent premature failure or process shutdown can be solved by several means. The surface area of the enclosure itself may serve as a passive means to dissipate this heat, providing the ambient conditions are below the desired enclosure interior temperature and the internal heat load does not cause an unacceptable rise in temperature. When this is not possible, an active approach is necessary.

Open loop powered ventilation, or closed loop cooling may be used.
Open loop ventilation uses ambient air to remove the heat, and may consist of small muffin type fans that exhaust or supply an electrical enclosure, at times with filters to prevent airborne aerosols and dust from entering the enclosure. The fans have the advantage of utilizing a minimum of enclosure space and will move a substantial volume of air where flow is virtually unimpeded. Cost and complexity is minimized. Where density of components impedes airflow, packaged blowers or motorized impellers may be arranged to operate against these higher static pressures. With a rack enclosure, supplemental fan trays may be used to spot cool or supplement other air-moving devices.

Where maximum internal enclosure design temperatures cannot be maintained using open loop ambient air cooling, closed loop devices need to be considered. Air to air heat exchangers, water to air heat exchangers, thermoelectric heat exchangers and air conditioning units are able to cool a confined amount of air within an enclosure. Heat is transferred to the respective devices' ambient side where an air mover or water coil transfers the heat to the room or outdoors.

Air conditioners and water to-air heat exchangers provide the greatest capacity to transfer heat in closed loop conditions. They have the unique ability to maintain a lower than ambient temperature and reduce the humidity within the controlled space. It is important to note that enclosure design temperatures may exceed the ambient temperatures, yet be below the electronic components' design limits. Depending upon the NEMA enclosure type, which designates the environmental hazard from which the contents are being protected, an air conditioner can be provided to operate in most locations. Locations subject to dust, dripping liquids, rain, wash down and corrosive atmospheres can utilize these "Special Purpose Air Conditioners".

A typical "Special Purpose Air Conditioner" operates as follows. Heat is transferred from the enclosure components by circulating air around and through them, the air is then cooled, dehumidified and returned to the enclosure without the admission of air from the outdoors. The heat is removed from this air within the air conditioner and discharged by means of a vapor compression refrigeration cycle. This takes place in a hermetically sealed system, utilizing either an air-cooled or water- cooled condenser coil. A schematic of a typical Air Conditioner is illustrated (see figure 1).

The compressor forces refrigerant, in vapor form, into the condenser coil where it is cooled by ambient air. As it cools, the refrigerant condenses into a liquid, which is passed through a filter to remove impurities and excess moisture. The liquid refrigerant flow is metered by a thermostatic expansion valve or capillary tube, to control its admission to the evaporator coil which is a part of the closed loop on the inside of the enclosure.

The refrigerant enters the evaporator as a liquid beginning to vaporize. As the blower or fan driven heated air from the enclosure passes through the evaporator coil, the heat is transferred to the refrigerant, converting the refrigerant to vapor. High levels of humidity present in the air are removed by condensation, the water is drained to the outside and evaporated in some cases. This cool, dehumidified air is then returned to the enclosure. After the heat is transferred to the refrigerant in the evaporator, the refrigerant passes into an accumulator, where any remaining liquid is separated. The gas then returns to the compressor to repeat the cycle in a continuous process.

Control of the system is generally kept simple. When power is applied to the air conditioner the evaporator blower starts and runs continuously. If the temperature within the enclosure is high, the condenser blower and the compressor turn on, operating until the thermostat setting is reached. The thermostat is used as a low limit setting. This is typically 75�F, the point at which the compressor and the condenser fan or blowers are turned off. Air within the enclosure continues to be circulated by the evaporator blower or fan, picking up heat from the components within the enclosure. The thermostat has a differential setting that is typically 12-15 degrees above the low limit setting. When the air circulated within the enclosure rises by this amount, or at about 90�F, the compressor and condenser blower turn back on reducing the enclosure internal air temperature once again. Therefore, at start up of an enclosure system, it would be normal for the internal temperature to rise to this temperature before the refrigerated cooling would begin. As the air cools, a balance of temperature within the enclosure is reached, ideally the compressor and condenser fan continue to run most of the time until the heat load changes.
 

It is important to understand that enclosure cooling is not "comfort "cooling as found in homes and buildings. Heat producing power and control components are typically limited to maximum enclosure air temperatures of 100�F to 110�F. The actual component surface temperatures are higher. Maintaining enclosure temperatures too low often becomes problematic. Condensation may form on live electrical surfaces if their temperature falls below the dew point of the air. Subsequent corrosion or electrical safety becomes a serious issue.

Various control features are available to operate in cooler ambient conditions found outdoors or in poorly heated settings. Compressor short cycling controls may be added to prevent damage caused by frequent starting when heat loads fluctuate.

The air conditioner typically carries an agency marking such as UL, Underwriters Laboratories which designates the environmental hazard from which the contents are being protected. This marking should be matched to the enclosure to be cooled. Typical examples include NEMA 12, (indoor use, protection from dust and dripping liquids) (see Figure 2), NEMA 3R, (outdoor use and rain proof) (see figure 3) and NEMA 4/X (outdoor or indoor use, protection from wash-down and corrosive environments) (see figure 4).

Sizing calculations for the selection of an air conditioner are accomplished with ease via software available on manufacturers' websites or on available software copies. The internal heat load is determined based upon measurement or estimation. Enclosure surface area, desired maximum internal enclosure temperature, degree of thermal insulation if any, ambient temperature and for outdoor use, solar load are used to determine the total heat load in BTUH. It is important to note that the solar load and the degree of insulation can become very significant. Entering a closed automobile after it has sat in the hot summer sun illustrates this point.

For best results be careful not to oversize the unit. Be certain that both the evaporator and condenser air flow paths cannot short circuit, or are impeded. Be cautious of adding protective covers to the outside of the unit which may reduce air flow and unit thermal performance. Seal the electrical enclosure to prevent humidity and outside air from entering. Closed loop enclosure cooling is the goal. Consult performance data, or contact the manufacturer for temperature conditions other than the rating points shown in most catalogs. Typical performance is shown in figure 5. A properly sized, well designed system, free of refrigerant leaks, with a stable power supply will cool critical systems trouble free for many years.

Should you have any technical questions please contact us

 
CABINET COOLING TIPS/MEETING DESIGN CHALLENGES

THINK ABOUT COOLING...EARLY!
Cooling needs should be evaluated early in the design process. Nearly all systems require some degree of forced cooling. Early estimates of the location of components in the cabinet, the heat to be dissipated, and the amount of space needed for the cooling device will save time, trouble and expense. 

AMBIENT AIR VS. CLOSED-LOOP COOLING
Keep it simple. If ambient air is cool and clean enough, use it. It's free. If the ambient is too hot, dirty or corrosive, a closed-loop system is needed. A Heat Exchanger is usually a lower-cost choice than an Air Conditioner. See if it will do the job. Don't over-cool. Don't oversize the cooling equipment.

FAN OR BLOWER?
Propeller fans are designed to move large volumes of air at low static pressure. Blowers are used in higher static pressure applications, and are at maximum efficiency when operating near their peak static pressure. Figure 2 shows their relative operating characteristics.

PRESSURIZE, DON'T VACUUMIZE!
Pressurization of the cabinet is far more desirable than drawing the air out. Plan to pump filtered air INTO the cabinet, to gain the advantage of using cracks between panels, around doors or other small openings as part of the exhaust area rather than as sources for the intake of dust and dirt. If pressurization is impossible and a fan or blower must be used to exhaust the enclosure, a filter at the air inlet is recommended.

KEEP IT CLEAN
Nothing is more important than CLEAN filters. Clogged filters restrict airflow and cause motors, compressors, etc. to work harder and fail prematurely. Timely filter servicing is vital to your system.

KEEP INLET AND EXHAUST AIR FAR APART
Be sure that all of the exhaust area is located downstream, as far as possible from the air inlet and beyond all heat-producing components. An open-base cabinet sitting only one-quarter inch off the floor can waste a substantial percentage of cooling air even if the air is directed upward initially. A properly planned air path will avoid all "short circuits" or losses by forcing the cool supply air to pass through the components that are to be cooled before reaching the exhaust area. This will allow for a maximum of cooling efficiency. 

LET NATURE HELP
Cooling air should enter the enclosure from as low as possible and leave the enclosure from above the highest hot component. Thus, the forced air flows upward through the heat-producing components and adds to the natural buoyancy of the heated air.

A "BOOSTER" CAN SAVE SPACE AND COST
A booster fan located downstream or at the outlet can draw added cooling power through densely packed components. It could permit the use of a smaller, quieter packaged blower than originally indicated, allowing more panel space for other uses.

ENTERING AIR NEEDS EXIT ROOM
The cross-section area of the airstream throughout the flow path in the cabinet should be at least equal to the effective area of the air intake. If this ratio is less, "choking" of the delivered air may result. On the basis of the average grille material, with 65% open or effective area, the following table gives the typical effective area which should be allowed for discharge.

19" Front Panel    Circular Fan
Intake                Intake 
 3.50"   28 sq. in.   6.50"  33 sq. in.
 5.25"   47 sq. in.   8.00"  50 sq. in.
 7.00"   68 sq. in.   9.00"  64 sq. in.
 8.75"   85 sq. in.   9.50"  71 sq. in.
10.50"  100 sq. in.  10.00"  78 sq. in.
For intake and exhaust grille and filter grille assemblies, use the Accessories and Options section.

USE DUCTS FOR EVEN COOLING
If the maintenance of an even temperature from top to bottom of the enclosure is important, ducts along the sides of the enclosure offer an ideal solution. Multiple duct outlets allow precise control of the location and quantity of air delivered. 

COMPONENT LOCATION
Where possible, locate heat sensitive electrical components toward the bottom of the enclosure, since the warmest air temperatures will be at the top. Maintain adequate spacing between components within the enclosure to minimize airflow restriction.

BAFFLES SOMETIMES WORK WONDERS
At times, an excessively hot component or an isolated area in the enclosure presents a problem in an otherwise well-cooled system. A baffle to channel air across the location is often the best solution.

VIBRATION ISOLATION
Neoprene vibration isolators minimize the possibility of trouble associated with vibration. All portions of a system will respond to periodic forces in varying degrees. This excitation can occur regardless of the balance or design of the air-moving equipment, since any given construction could be in harmony with any of the driving forces in the blower motor. If the sympathetic vibration level is unacceptable, slight weight change or redistribution will usually alleviate the problem.
OkSolar.com Affiliate

 

 


Solar Light Tower, Light Tower, Refugee Camps Solar Light Tower, mobile light towers, Job Site Solar Light Tower, Portable Solar Light Towers, Solar Powered Construction Light Tower,


 

 

OkSolar.com Serving The Industry Since 1988.
  All rights reserved. All trademarks or product names mentioned herein are the property and responsibility  of their respective owners. 
Credit Pictures provided by PIX along with DOE/NREL 

Email to Us | Our Philosophy  |Terms & Conditions | Powered By GeneralCommunications.com