Electrical enclosures are generally designed to allow cooling by natural ventilation, supplemented sometimes by forced ventilation. This usually works well, but there are situations when overheating of electrical panels occurs due to internal heat load, environmental, ventilation, and air flow capacity constraints.
In these situations, enclosure air conditioners solve high temperature problems inside electrical enclosures, increasing component life and reducing the risk of overheating leading to component failure.
The heat load of an electrical enclosure is the heat generated in that cabinet, usually expressed in Watts. Sources of heat generation include:
Electrical enclosures placed in hot industrial environments, for example, near ovens, kilns, and furnaces cannot depend on natural cooling because ambient air temperature is close to or above optimum electrical equipment temperatures and items such as electrical drives, which are susceptible to overheating, may malfunction or fail. Although the maximum operating temperature of some devices reaches 140 °F, many others cannot exceed 120 °F. In all cases, component life is extended and doubled for every 10 °F decrease in operating temperature. Electrical enclosure air conditioning is the only viable method of maintaining safe electrical equipment operating temperatures in a hot industrial environment.
The effect of solar radiation on metal equipment is such that in hot climates surface temperatures of metal objects can easily exceed 100 °F. In these conditions, natural ventilation may be insufficient to prevent internal temperatures of electrical enclosures from reaching unsafe levels. These situations are common in hot, dry, tropical, and sub-tropical areas. When enclosures must be outdoors an enclosure air conditioner may be required.
Electrical equipment in dusty environments needs to be properly enclosed and natural ventilation is not recommended as dirt and dust can affect operation of the moving parts of relays and contactors. Some dusts may be corrosive or conducting and need to be kept away from electrical components. The best method of equipment protection is the use of sealed electrical enclosures provided with suitably equipped enclosure air conditioners designed for use in dusty environments.
Electrical enclosures in poorly ventilated areas may overheat if the heat load from the electrical equipment inside the enclosure is excessive. Electronic equipment used to control motors produce a lot of waste heat that needs to be dissipated, or the enclosure may overheat. Other heat sources are electronic power supplies and air cooled transformers. An enclosure air conditioner will remove the excess heat from electrical enclosures and keep them cool.
In some situations, space available for electrical panels is constricted. Examples include electrically powered coal and ore reclaiming equipment, mining equipment, earth moving equipment, and ships. Often this equipment is supplied at medium voltage power using a trailing cable or overhead pantograph and makes extensive use of variable speed drives. Enclosure air conditioning can be used to keep these electrical enclosure temperatures within operating parameters.
The risk arising from the overheating of electrical components in panels cannot be under estimated. Many devices cannot withstand temperatures above 140 °F (60 °C) and electrical enclosures may achieve these temperatures in harsh environments with high ambient heat loads and poor ventilation.
Once a temperature of 140 °F is reached, conductor resistance increases, leading to severe localized overheating especially of components carrying large currents. Thermal runaway becomes a distinct possibility which may lead to components burning out and a subsequent risk of fire and explosion. Air conditioning of electrical enclosures can prevent component temperatures from exceeding safe levels and has the added benefit that cooler running extends the life of the electrical equipment.
Extend the life of electrical components in your application by contacting Thermal Edge experts today to select an air conditioner suited to your enclosure and application.
Our industrial air conditioners are engineered for dependable performance at high ambient temperatures, as enclosure cooling units can be installed in many industrial environments including harsh and other challenging operating conditions. In addition, a full line of factory installed accessories and options allow for a more customized cabinet cooling solution to optimize performance in certain applications. To view these options, explore our complete line of enclosure accessories. For instances where the ambient air can accomplish the desired heat removal, a fan or blower may be all that is required.
Many of our sealed enclosure cooling units feature a programmable thermostat, which allows for accurate and versatile enclosure cooling. With the use of a separate "hot key" they can also be utilized for remote monitoring and alarms, using Modbus protocol. Depending on the model series, sealed enclosure cooling for NEMA Enclosure Ratings of 12, 3R, 4 & 4X can be maintained.
The Guardian/GuardianX and SlimKool enclosure cooling units have been designed for both indoor or outdoor use, without the need for weather shielding. The popular Guardian/GuardianX Series offers the greatest variety of models, sizes and BTU/H outputs to choose from, as well as NEMA 4 and 4X Ratings, and various voltages, including 480 Volt. The SlimKool Series is specifically designed to mount on electrical enclosures where available vertical space is limited, a common problem in many industrial applications. These are also available in NEMA 4 and 4X versions as well as 480 Volt. Our patented Hazardous Location Series offers enclosure cooling in areas where NEC class 1, Division 1 & 2 is required; these units use the cabinet's existing purge system. For indoor cabinets where small capacities are required, the Micro-Mini, Narrow Mini and Profile Series are excellent choices. If clean water is available, our TrimLine Water Cooled Series is recommended where high ambient temperatures and contaminated air is present. In some applications, the only available cabinet space for mounting an enclosure cooling unit is on top, horizontally. In these instances, the Advantage, Horizontal Super Mini and Compact Plus Series are available to meet your needs. The Intrepid Series is best for high capacity, outdoor applications.
If you have an older Kooltronic air conditioner or a competitor's unit that needs to be replaced, we offer adaptor plates and plenums that will minimize enclosure modifications, making the switch out much easier.
Kooltronic Enclosure Air Conditioners are engineered for reliable performance and long useful life. All applicable components are UL/CSA Listed or Recognized. Our enclosure cooling units are developed in-house using an integrated 3D design process and drawings are available in 2D and 3D formats for inclusion in your design specifications.
Kooltronic uses revision controlled, paperless manufacturing documentation to ensure uniformity and quality. Our New Jersey production facility utilizes robotic sheet metal fabrication, an automated powder paint line and continuous formed tubing bending equipment to reduce refrigerant leak potential. Bar-coded evacuation and charge, and final test inspection is standard for all cooling systems before being shipped to our customers.
Kooltronic also designs and manufactures a variety of air conditioners to meet unique specifications. We invite your inquiries regarding our quick-response modification and custom-design cooling system capabilities.
Top 5 Differences between Cabinet and Wall Mounted Air Conditioner
Air conditioners have become part and parcel of our daily lives. Nowadays, air conditioners come in varying sizes and types and choosing one of your choices can be tricky. However, every air conditioner&#;s fundamental principle is to utilize a refrigerant to move heat energy from inside to outside. Mainly, there are two types of air conditioners, namely, wall-mounted and cabinet. Some of the major differences between them are given below.
Differences between Cabinet and Wall Mounted Air Conditioner
Structural difference
Wall-mounted air conditioners are generally hung over the wall and have two air pipes routed from the back directly through the wall. The condenser in these air conditioners is placed inside the body. However, in cabinet air conditioners, all the elements, the evaporator, condenser, and compressors are located in one place. These air conditioners sometimes also come with heating coils or a natural gas furnace. This is why it is often called centralized air conditioner as well.
Portability
One of the primary differences between the wall-mounted and the cabinet air conditioner is the place where they are mounted. As the name suggests, wall mounted air conditioners are fixed in a wall. On the other hand, cabinet air conditioners are portable and can be transferred from one place to another, depending upon the size.
Cooling Capacity
Wall-mounted air conditioners are often placed in smaller places. For instance, using wall mounted air conditioners is feasible in rooms having a fewer number of people. In contrast, cabinet air conditioners are actually large room air conditioners and used in somewhat bigger halls with larger numbers. This is due to both the air conditioners&#; cooling capacity as cabinet air conditioners are more likely to produce more cooling compared to the wall-mounted air conditioners.
Working method
A wall-mounted air conditioner works by drawing the air from the room, which then passes through a condenser and is cooled using a cooling agent. This cold air is then thrust into the room; the hot air and moisture are thrown out through an external unit.
However, in a cabinet, the air conditioner, heating, ventilation, and air conditioning all can be performed. Air return is the starting point of the ventilation unit where it is being sucked and passed through a filter.
A compressor is responsible for cooling, and it converts the refrigerants from gas to liquid and sends it to the coils where it cools the air. It also has exhaust outlets responsible for the expulsion of the exhaust gases.
Advantages of Wall Mounted Air Conditioner
Energy Efficient
Wall-mounted air conditioners consume less energy than centralized air systems or even traditional air conditioners. It is perfect to use them in smaller rooms as these air conditioners are beneficial for compact spaces compared to the central system. Hence it also consumes less energy.
Accessibility
The main advantage of wall-mounted air conditioners is that they can cool or heat any room with the flip of a switch. This is something neither centralized air conditioners nor traditional air conditioners can perform. Wall-mounted air conditioners provide the good of both worlds.
Advantages of Cabinet Air Conditioner
Cleaner Air
In cabinet air conditioners, the air is drawn out of the room through return air ducts, and the air is passed through an air filter, which blocks certain pollutants or airborne particles. Using air supply ductwork, this air is then supplied back to the room.
Programmable Temperatures and Alarms
Cabinet air conditioners provide the user with a chance to set their own preferable temperatures. Some models come with the coded program that can send you an alarm if things go south, provided that a device of yours is connected with it.
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The use of enclosure coolers has grown exponentially due to the demands created by higher cabinet heat loads associated with more sophisticated electrical equipment.
In an attempt to lower costs, manufacturers placed equipment closer to the plant, exposing it to harsher environments. Before the invention of enclosure coolers in the s, electrical enclosures relied solely on ventilation and many components operated at elevated temperatures.
This stresses the equipment, leading to system failure and premature wearing down of components. Ultimately, leading to costly repairs and pricey equipment replacement.
As technology progressed, so did issues. Output variability, nuisance tripping, and unexpected equipment failure were common.
These complications were eventually linked to high temperatures. Simple ventilation could no longer meet demands to keep enclosures below operating temperature for many electrical components.
Manufacturers needed something more powerful for higher heat loads and hostile environments.
More advanced cooling systems have been created to keep enclosures running at their highest efficiency and reliability.
Control Maximum Enclosure Temperatures &#; Panel coolers keep your system from feeling &#;hot, hot, hot.&#; Few devices can be used above 120 degrees Fahrenheit and many are limited to 105 degrees Fahrenheit. Average summer temperatures in the US can be 105 degrees or more. With additional heat created by solar radiation and other factors, your equipment could easily be in a damaging environment.
Enclosures Keep Out Harmful Agents &#; Dirt, debris, dust, corrosive vapors and water can all be detrimental to expensive electrical equipment. Enclosure coolers help protect equipment from substances that can cause harm, preventing system failure and expensive repairs.
Extends Life of the Equipment &#; Research has shown that for every 18 degrees above normal room temperature (72-76 degrees), the reliability of electrical components is reduced by half. Over-exerting components in a hot environment leads to a shorter life span for your equipment and costly repairs.
Prevents Malfunctioning Due to Overheating &#; Keeping the enclosure at optimal operating temperatures will prevent over usage and will extend the life of your equipment exponentially.
Removes Excessive Heat &#; Less heat will result in fewer problems. With no excessive heat, there will be no unnecessary repairs due to overworking the system.
Saves You Money! &#; This is probably the most exciting benefit of adding a panel cooler to your system. Eliminating the problems associated with high heat will save you money by protecting your expensive electrical equipment from failure and expensive repairs associated with an over-exerted system.
All electrical systems give off heat and the environment where the enclosure is located can also add to a higher heat load.
Internal Heat Sources Include:
AC Drives/inverters
Battery back-up systems
Communication gear
PLC systems
Power supplies
Routers and switches
Servers
Transformers
External Heat Sources Include:
Blast furnaces and foundries
Engine rooms
Food processing factories
Industrial Ovens
Hot Climates
Manufacturing plants
Outdoor solar heat gain
Uninsulated or non-air conditioned buildings
The National Electrical Manufacturer&#;s Association (NEMA) ratings explain what the enclosure&#;s intended use is for, from small pushbutton boxes to large full sized room enclosures.
NEMA ratings standardize product specifications while establishing performance criteria.
In other words, they make sure consumers are buying the right enclosure to keep electrical components safe based on the cabinet&#;s environment and type of equipment inside.
It is important for the panel cooler to have the same NEMA rating as the electrical enclosure. If the panel cooler and the enclosure have different ratings it will not meet NEMA standards. This is a bad thing because your electrical equipment will not get the correct protection that it needs.
Read Enough But Still Have Doubts?
Using a BTUH calculator is the perfect solution to enclosure ac sizing. It does most of the work for you, and who doesn&#;t love a shortcut?
The ISC Sales BTUH calculator takes all of these factors into account when calculating heat loads:
Enclosure Dimensions:
A large enclosure will need more cooling power than a small enclosure.
Environmental Temperatures:
To accurately read ambient temperatures for indoor enclosures:
Measure the temperature far enough away from your cabinet so your reading will not be skewed by heat radiating from the enclosure, at least 20 feet away
Take multiple measurements throughout the day and use the highest recorded temperature as a guideline. Make sure you are recording temperatures during peak operation time when all equipment is running.
Use a calibrated thermometer.
For outdoor enclosures&#;
Don&#;t measure the surface temperature of the cabinet. This will give you a higher reading because it is affected by heat from the sun and cooling from the shade.
Think about seasonal changes in the area and use the highest expected temperature. You can find accurate regional figures by visiting weather websites like this one Weather.gov
Use a calibrated thermometer.
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Heat Load:
To calculate heat load, make a list of all the equipment in the cabinet, paying special attention to the manufacturer&#;s model numbers. Use this information to look up the amount of heat in watts that each component generates, then add it all up to get the heat load.
*If you can&#;t find the numbers in watts, but you know the horsepower (HP) remember that 1HP= 746 W. *
Enclosure Materials:
Enclosures made of aluminum have different NEMA ratings than polycarbonate ones and they can protect against different environments. They also have different cooling needs.
Insulation:
Just like wrapping yourself up in a blanket, insulation can trap heat in. This is an advantage for enclosures located in climates with cold winters. However, the insulation can create problems during warmer weather if it is not considered while deciding on which enclosure cooler will work best for you.
Location:
Whether the enclosure is inside, outside, in an air-conditioned environment, in direct sunlight or near high-heat producing equipment can all affect internal temperatures in the cabinet.
Ambient Air Conditions:
The air surrounding the enclosure plays an important role in deciding which enclosure cooler works best.If harmful, potentially explosive dust entering the cabinet is a concern the enclosure will need a different cooler type than if you simply needed a cooler to protect components from the high temperatures of an outdoor climate.
Paint Color:
Darker colors will trap heat, while lighter colors will not.
These factors are all crucial for determining which enclosure will best work for your application. An incorrect heat calculation can result in using the wrong cabinet cooler.
Using the wrong cooler will keep your equipment from working at its best. Components will overload, leading to expensive repairs and you will experience the same problems that led you to purchase a cooler.
Enclosure coolers are separated into two categories based on how much they can lower internal temperatures in an electrical cabinet.
Every Above Ambient system and every Sub-Ambient system cool enclosures differently and are for wide-ranging applications and environments.
These enclosure coolers work best for electrical cabinets that have a higher internal temperature than the environment around it.
Above Ambient systems can only be used when the ambient, or surrounding, temperature is lower than the desired enclosure temperature.
This means that these systems do not actively make your enclosure colder, they simply circulate the hot air in the enclosure with the cooler air present in the environment around it. Sometimes you don&#;t need all the bells and whistles and just need a simple solution.
An enclosure in a well air-conditioned environment where the average ambient temperature is 76 degrees is an ideal situation for an Above Ambient cooler.
Above Ambient coolers tend to be less pricey, but have a limited cooling capacity.
Fan Filter:
Fans and grills work together to displace hot air inside the enclosure with cooler air. Incoming air is filtered to protect components from dust and debris.
These systems work just like a fan you&#;d use inside your home. They do not physically lower the temperature of your home, but they do move and cycle air creating a cooler climate and have the added bonus of filtration.
Pros:
Works well in temperature controlled environment
Simple, non-complex system
Inexpensive option
Cons:
Maintenance requires regular filter replacement
Limited NEMA rating: water, dirt and other contaminants can still enter the enclosure
Air to Air Heat Exchanger:
Air to Air systems recirculate the air in the enclosure. Heat is transferred using a heat pipe running from the hot enclosure to cooler ambient air.
The heat pipe is a sealed tube filled with a very low-pressure refrigerant liquid. The bottom of the pipe is warmed by the hot air in the cabinet, causing the refrigerant to vaporize and rise to the top of the pipe.
The top of the pipe comes into contact with cooler ambient air. Once the refrigerant hits the cooler air it releases its heat, condenses and then returns to the bottom of the pipe. Small fans are also used circulate the air inside and blow outside air over the heat pipe.
Air to Air Heat Exchangers function with a close looped design, meaning they recirculate the air already present in the enclosure, which prevents water, dirt and other contaminants from entering the cabinet.
Even though heat is transferred between inside and outside air they never come into contact with each other.
The cool top and warm bottom of the pipe are in separate compartments. The bottom is completely sealed, allowing only hot air from the top to enter the heat exchanger and the cool air to return to the enclosure. The top compartment is exposed to the ambient air circulated by a fan, discharging heat.
Pros:
Works well both indoors and outdoors
Can be used with NEMA rated enclosures
Extremely reliable, heat pipe assembly usually lasts 300,000 hours or more
Minimal maintenance, inexpensive
Cons:
Cannot cool below ambient temperatures
Must be installed vertically
These types of enclosure coolers are the best for enclosures with a high heat load in an environment that is also hot.
Sub-ambient coolers actively lower temperatures inside of the enclosure to below ambient temperatures.
A cabinet located outside of a manufacturing plant in the Nevada desert is an example of when a Sub-Ambient cooling system would be best. The environmental temperature of the Mojave Desert routinely reaches temperatures 100 degrees Fahrenheit by the beginning of May. Whew! Talk about hot!
Typically, these systems have a higher cost but in return provide greater cooling power.
Enclosure Air Conditioner Units:
Enclosure air conditioning units work like your ac unit inside your home. They cool enclosures using this principle- fluid heats up when compressed and cools when it is expanded.
A high-temperature/high-heat gas is created when a vaporized refrigerant is compressed. The gas is then shot through a series of coils while a fan blows ambient air across them. This removes the heat from the gas, transferring it to the surrounding environment and returns the gaseous refrigerant to liquid.
Then the refrigerant passes through an expansion valve where it becomes cold as it is expanded and evaporated before going into the evaporator coil. Air from inside the cabinet is then blown across the evaporator coil by another fan, moving the heat from the electrical components to the refrigerant. Finally, the vaporized refrigerant returns to the compressor where the process begins again.
Pros:
High cooling capacity
Compatible with many applications
Units range from 1,000 BTUH to 20,000 BTUH
Cons:
More maintenance: replacing filters, checking condenser coils for scale and other buildup (Delta T enclosure ACs include a condensate elimination system that will reduce the need for maintenance)
Horizontal or vertical orientation only/stationary
Thermoelectric Air Conditioner or Peltier Coolers:
Thermoelectric cooling uses the Peltier effect to create a temperature difference by transferring heat between two electrical junctions. A voltage is applied across joined conductors to create an electrical current.
When the current flows through the intersection of the two conductors, heat is removed at one junction and cooling occurs. Heat is then deposited at the other junction.
Finally, the hot side is attached to a heat sink which remains at ambient temperatures, while the cool side drops below room temperature.
Pros:
No moving parts or circulating liquid
Environmentally friendly, it doesn&#;t require the use of potentially harmful coolants
Can also be configured to generate heat during colder seasons
Long life with little to no maintenance
Cons:
Limited cooling capacity
Vortex Coolers and ACs:
Vortex coolers&#; primary component is a Ranque-Hilsch vortex tube. This device&#;s cylindrical generator uses compressed air to create a swirling effect that separates air into hot and cold air streams.
Compressed air enters a chamber in the vortex tube and is forced to spin in a tight, high-speed circular path at one million revolutions per minute, like a tornado. At the end of this tube is a needle valve where a small portion of the air exits as hot air exhaust.
The remaining air is forced back through the center of the incoming air stream at a slower speed. The heat in the slower moving air transfers into the faster moving incoming air.
The cooled air flows through the center of the generator and exits through a cold air exhaust point. Only 40 percent of air is lost into the atmosphere through exhaust valves, while the remaining 60 percent cools the enclosure.
This process provides a positive purge, pressurizing the enclosure. This pressure will keep out contaminants such as dirt, dust, and debris.
Both vortex coolers and vortex air conditioning units utilize this technology. The main distinctions between the two are their shape and the type of thermostat used to regulate them. Vortex coolers are cylindrical in shape. They are fitted with an electrical thermostat to precisely regulate the cabinet&#;s internal temperatures.
Vortex air conditioners are shaped like a box, self-contained and have a mechanical thermostat. They run quieter than coolers and are generally easier to install.
Pros:
Suitable for harsh or hazardous environments
Little to no maintenance
No moving parts, which means a long life
Cons:
Needs clean/dry compressed air
Purge/Pressurization Systems:
Purging and pressurization systems are one of the most versatile options for explosion protection. They can be used with any enclosure cooler in hazardous locations. Purge and pressurization systems prevent things from going &#;boom&#; by first purging or removing, the flammable gasses that could explode.
After the purge, compressed air or inert gas fills the enclosure, which prevents any potentially flammable ambient air or dust from entering the cabinet through any leaks. This pressurization, using a non-reactive gas, limits the chances of an explosion due to interactions with ambient air or dust.
For systems that need protection from dust, the purge process is omitted to prevent raising explosive dust. Instead of purging, the interior is inspected for dust, and if it is present the cabinet is then cleaned manually.
Before you add a purge/pressurization system to your enclosure be sure to define your hazard, know the classification of the area, ratings of the equipment inside the enclosure, type of enclosure; the position of doors, windows and any accessories, and how much power the electrical equipment inside uses.
Pros:
Versatile applications, they can be added to almost any system
Cons:
They need a constant source of compressed air
Still unsure of which enclosure cooler will fit your needs?
Needs vary so much from application to application it is hard to determine what will work best.
But you&#;re in luck! The staff at ISC Sales is very knowledgeable, able to answer any of your questions and will ensure that you get the most efficient product for your business. Contact us today and have the enclosure cooler that&#;s perfect for you tomorrow.
We're committed to furnishing easy,time-saving and money-saving one-stop purchasing support of consumer for Cabinet air conditioning
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