Literature > White Papers > A Guide to Protecting Electrical Enclosures
A GUide to Protecting Electrical Enclosures
Heat Load
The most important thing to consider when selecting an electrical enclosure cooler is the unit’s total heat load, which is made up of two main components. First is the internal heat load; the heat that is generated by the electric components inside the enclosure. Second is the external heat load; this is the amount of heat that is either gained or lost through the walls of the enclosure.
The internal heat load can be found in three different ways:
The user knows the amount of heat that the electronics create (in either watts or btu/h).
The user knows the total power that all the electric components consume. Then we can estimate that about 10-15% of this is generated as heat load (this is assuming electronic efficiency is between 85-90%).
The user measures the existing temperatures inside the enclosure at the top of the unit and the existing temperature outside of the enclosure. The difference between these temperatures, along with the total surface area of the enclosure that is subject to the temperature difference, allows for the calculation of the internal heat load.
If the desired temperature inside the enclosure is less than the temperature outside the enclosure, then there is a heat load gain in the enclosure. Heat load gain depends on the difference in temperature, the amount of surface area that is subject to the temperature difference, how thick the enclosure walls are, if the enclosure is insulated or not, and the enclosure material. In this calculation, the external heat load is then added to the internal heat load to get the total heat load.
If the desired temperature inside the enclosure is greater than the temperature outside the enclosure, there is a heat load loss from the enclosure. This loss is then subtracted from the internal heat load to get the total heat load.
A helpful tool to get a better understanding of enclosure cooling capacity needs is this heat load calculator.
Location of Enclosure
When selecting an enclosure cooler, it’s important to consider what type of environment the unit will be placed in. While we already talked about the effects of the sun and heat, the outside elements and operation hazards need to be considered as well.
Outside: If an enclosure is subject to the outdoors (think rain, wind, ice, and frost) it’s important that the enclosure cooling system has a NEMA 4 or 4X rating. This is important to ensure that the interior of the enclosure remains dry and clean.
Inside General: When placed indoors, and not subjected to a washdown operation or hazardous environment, typically a NEMA 12 enclosure cooler is suitable.
Washdown: In washdown operations, a NEMA 4X enclosure cooler is needed to maintain the sanitary conditions in the facility and to ensure that the washdown solution does not enter the enclosure.
Hazardous Locations: If the enclosure is situated in one of several hazardous locations, it’s vital to comply with IECEx, ATEX, and UL recommended system requirements.
Temperature Control Needs
Types of Enclosure Cooling Solutions
Fan Cooling Systems: Fans are typically the most affordable option but can also be the least successful. Fans are constrained in their cooling capabilities: they allow little to no cooling adjustability and are reliant on the ambient air temperature. When factories have nearly invisible oil, aerosols, dust, and other contaminants in the air, a fan draws these contaminates into the cabinet and onto electronics and circuit boards. Although this air may temporarily cool the components, it deposits the contaminants on the electronics, effectively insulating the electronic components. Eventually, this will cause the electronics to overheat, defeating the purpose of the fan in the first place.
Thermoelectric Cooling Systems: Thermoelectric coolers use the Peltier effect to create cooling by converting an electric current to create a cold junction and a hot junction. Fans blow air across the cold junction (a heat sink) to cool the air inside the enclosure. This cooling method has no moving parts and uses very little power. However, it is usually more expensive to purchase than other cooling types and therefore is primarily used in military and aerospace applications.
Refrigerant (“Freon”) Based Cooling Systems: Refrigerant based cooling systems are more effective than fans, but they are limited in the environments in which they can operate. They typically do not function in ambient temperatures greater than 131°F (55°C). Refrigerants, typically, require an extensive physical footprint and higher upfront costs. In addition to the high upfront cost, refrigerant-based systems need periodic maintenance which costs additional time and money. Although an effective cooling option, they can become very time-consuming and costly to maintain properly.
Vortex Cooling Systems: Vortex cooling is an effective, safe, and low maintenance way to cool enclosures. And while vortex cooling uses compressed air, thermostatically controlled systems minimize compressed air usage to reduce operational costs. Vortex tube technology converts compressed air into cold air without the use of electricity or coolants. Vortex cooling can reduce the temperature of the compressed air by 50 F° (28°C) or more. This means that enclosures are supplied with cold, slightly pressurized air, while oil and dust are also prevented from entering the cabinet. Vortex cooling systems have no moving parts, so they require very little maintenance, apart from occasionally changing a filter element, which ensures clean, dry air enters the enclosure. Vortex coolers are built to last and provide years of dependable cooling to ensure facility processes continue operating smoothly.
Conclusion
For more information on how to keep your enclosures safe and productive, contact one of our experienced engineers to discuss your application needs at sales@vortec.com.
Literature > White Papers > A Guide to Protecting Electrical Enclosures
A GUide to Protecting Electrical Enclosures
Heat Load
The most important thing to consider when selecting an electrical enclosure cooler is the unit’s total heat load, which is made up of two main components. First is the internal heat load; the heat that is generated by the electric components inside the enclosure. Second is the external heat load; this is the amount of heat that is either gained or lost through the walls of the enclosure.
The internal heat load can be found in three different ways:
The user knows the amount of heat that the electronics create (in either watts or btu/h).
The user knows the total power that all the electric components consume. Then we can estimate that about 10-15% of this is generated as heat load (this is assuming electronic efficiency is between 85-90%).
The user measures the existing temperatures inside the enclosure at the top of the unit and the existing temperature outside of the enclosure. The difference between these temperatures, along with the total surface area of the enclosure that is subject to the temperature difference, allows for the calculation of the internal heat load.
If the desired temperature inside the enclosure is less than the temperature outside the enclosure, then there is a heat load gain in the enclosure. Heat load gain depends on the difference in temperature, the amount of surface area that is subject to the temperature difference, how thick the enclosure walls are, if the enclosure is insulated or not, and the enclosure material. In this calculation, the external heat load is then added to the internal heat load to get the total heat load.
If the desired temperature inside the enclosure is greater than the temperature outside the enclosure, there is a heat load loss from the enclosure. This loss is then subtracted from the internal heat load to get the total heat load.
A helpful tool to get a better understanding of enclosure cooling capacity needs is this heat load calculator.
Location of Enclosure
When selecting an enclosure cooler, it’s important to consider what type of environment the unit will be placed in. While we already talked about the effects of the sun and heat, the outside elements and operation hazards need to be considered as well.
Outside: If an enclosure is subject to the outdoors (think rain, wind, ice, and frost) it’s important that the enclosure cooling system has a NEMA 4 or 4X rating. This is important to ensure that the interior of the enclosure remains dry and clean.
Inside General: When placed indoors, and not subjected to a washdown operation or hazardous environment, typically a NEMA 12 enclosure cooler is suitable.
Washdown: In washdown operations, a NEMA 4X enclosure cooler is needed to maintain the sanitary conditions in the facility and to ensure that the washdown solution does not enter the enclosure.
Hazardous Locations: If the enclosure is situated in one of several hazardous locations, it’s vital to comply with IECEx, ATEX, and UL recommended system requirements.
Temperature Control Needs
Types of Enclosure Cooling Solutions
Fan Cooling Systems: Fans are typically the most affordable option but can also be the least successful. Fans are constrained in their cooling capabilities: they allow little to no cooling adjustability and are reliant on the ambient air temperature. When factories have nearly invisible oil, aerosols, dust, and other contaminants in the air, a fan draws these contaminates into the cabinet and onto electronics and circuit boards. Although this air may temporarily cool the components, it deposits the contaminants on the electronics, effectively insulating the electronic components. Eventually, this will cause the electronics to overheat, defeating the purpose of the fan in the first place.
Thermoelectric Cooling Systems: Thermoelectric coolers use the Peltier effect to create cooling by converting an electric current to create a cold junction and a hot junction. Fans blow air across the cold junction (a heat sink) to cool the air inside the enclosure. This cooling method has no moving parts and uses very little power. However, it is usually more expensive to purchase than other cooling types and therefore is primarily used in military and aerospace applications.
Refrigerant (“Freon”) Based Cooling Systems: Refrigerant based cooling systems are more effective than fans, but they are limited in the environments in which they can operate. They typically do not function in ambient temperatures greater than 131°F (55°C). Refrigerants, typically, require an extensive physical footprint and higher upfront costs. In addition to the high upfront cost, refrigerant-based systems need periodic maintenance which costs additional time and money. Although an effective cooling option, they can become very time-consuming and costly to maintain properly.
Vortex Cooling Systems: Vortex cooling is an effective, safe, and low maintenance way to cool enclosures. And while vortex cooling uses compressed air, thermostatically controlled systems minimize compressed air usage to reduce operational costs. Vortex tube technology converts compressed air into cold air without the use of electricity or coolants. Vortex cooling can reduce the temperature of the compressed air by 50 F° (28°C) or more. This means that enclosures are supplied with cold, slightly pressurized air, while oil and dust are also prevented from entering the cabinet. Vortex cooling systems have no moving parts, so they require very little maintenance, apart from occasionally changing a filter element, which ensures clean, dry air enters the enclosure. Vortex coolers are built to last and provide years of dependable cooling to ensure facility processes continue operating smoothly.
Conclusion
For more information on how to keep your enclosures safe and productive, contact one of our experienced engineers to discuss your application needs at sales@vortec.com.