Understanding enclosure cooling technology

Rittal reveals the technologies behind its latest enclosure climate control system.
By Jack Smith, content manager, CFE Media May 13, 2016

Rittal gave a sneak preview of the wall-mounted cooling units Blue e+ at Pack Expo 2015 prior to introduction at Hannover Messe 2016. Rittal says the unit saves 75% energy compared to traditional cooling due to speed-regulated components and heat pipe tecCFE Media spoke with Eric Corzine, product manager, Climate Control for Rittal Corp. in Schaumburg, Ill., about the technology behind the Blue e+, the company’s newest enclosure climate control product. Rittal has been in full production since August 2015, and units are available for immediate shipment. "We asked our customers what they would like in enclosure air conditioners that they don’t have," said Corzine. "They want an environmentally responsible and energy efficient product, and the ability to accommodate different voltages and frequencies of a global market."

CFE Media: What’s different between the Blue e and the Blue e+?

Eric Corzine: The key differences between the Blue e+ and its Blue e predecessor include a hybrid system that uses active and passive cooling technologies. The active cooling system operates using a traditional compressor-based unit. The passive system uses Rittal’s heat pipe technology. Heat pipes work like heat exchangers.

CFE Media: How much more efficient is the Blue e+?

Corzine: Because of the hybrid design, the Blue e+ is seeing energy savings of around 75%. It also has a significantly reduced hysteresis control. Temperature swings were reduced from 9 F to around 0.36 F. Another unexpected benefit was that better temperature control translates to less condensation within the enclosure.

CFE Media: Could you explain the hybrid design?

Corzine: Active cooling is the traditional compressor-based cooling system. The passive system is based on heat pipe technology within the Blue e+ cooling unit. There are no moving parts except for a fan. Heat pipe technology is not new. But combining passive and active circuits is new. If the ambient air temperature is lower than the enclosure temperature, the Blue e+ would use the heat pipe. You’re not turning a compressor on and off, you’re not getting those electrical spikes because it’s using the heat pipe. If the ambient temperature increases, the heat pipe alone can’t cool the enclosure. Then it will turn on the active side to the extent that it needs it. Previous units without this technology—traditional compressor-base air conditioners—are either on or off. The Blue e+ will adjust itself. The fans we are using within the active side are dc motors, which are more efficient than the electrically-commutated motors.

CFE Media: How stable is the temperature control with the new unit?

Corzine: We are able to control hysteresis compared to traditional units. Because of the hybrid system, we have decreased the unit’s temperature swings from 9 F to around 0.36 F. You’re getting a lot more consistent temperature within your enclosure, which goes back to the energy efficiency, but it also goes to the longevity of not only your air conditioner, but your components within the enclosure as well.

CFE Media: You said your customers want the ability to accommodate different voltages and frequencies of a global market. How do you accomplish that?

Corzine: In addition to the energy savings, we use inverter technology, which enables us to deploy this unit anywhere in the world regardless of the electrical source in that country. It doesn’t matter where the unit is going. It senses the power source, you hook it up, it knows what it is, and it starts running."

Jack Smith, content manager, CFE Media, jsmith@cfemedia.com.

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