Tag Archives: heat dissipation

Latest Qpedia Now Available for Download

Qpedia Thermal eMagazine June 2013

Qpedia Thermal eMagazine June 2013

Qpedia Thermal eMagazine, Volume 7, Issue 6, has just been released and can be downloaded at: http://www.qats.com/Qpedia-Thermal-eMagazine/Back-Issues.

This month’s featured articles include:

Enhancing Heat Sink Performance Using Thermoelectric Coolers

With the increase in the power dissipation of components and the parallel reduction of their size, engineers and researchers across the globe have been predicting that the era of air cooling might come to an end. Even though in some applications, with very high power dissipations such as IGBTs, air cooling may not be adequate and liquid cooling is a must; air cooling will continue to be the first choice for most electronic cooling applications for many years to come. Advances in air cooling continue to extend its use and the implementation of thermoelectric coolers (TECs) in heat sink applications is one such effort.

Immersion Liquid Cooling for Servers in Data Centers

Data center designers and operators have invented many ways to improve the data center’s thermal efficiency, such as optimizing the rack layout and air conditioner location, separating cold aisles and hot aisles, optimizing the configuration of pipes and cables in under-floor plenum, introducing liquid cooling to high-power severs. While the above methods can improve the data center heat load management, they cannot dramatically reduce the Power Usage Effectiveness (PUE). This article reviews two relatively new solutions: active single-phase immersion cooling technology proposed by Green Revolution Cooling (GRC) and a passive two-phase immersion cooling technology proposed by the 3M Company.

Industry Developments: Piezoelectric Cooling

Piezoelectric fans and jets must overcome various materials, thermal and mechanical challenges to become widely used in electronics cooling, but because they consume just 1/150 of the electricity of circular fans, run with little noise and have no parts that will wear out, they remain of great interest. In this article, a number of issues are addressed, including the inverse effect of the piezoelectric phenomena and dual piezoelectric cooling jets.

Technology Review: Innovative Cold Plate Designs, 2007 – 2012

In this issue our spotlight is on innovative cold plate designs. There is much discussion about its deployment in the electronics industry, and these patents show some of the salient features that are the focus of different inventors.

& Cooling News featuring the latest product releases and buzz from around the electronics cooling industry.

Download the issue now.

Not a Qpedia subscriber? Subscribe Now for free at: http://www.qats.com/Qpedia-Thermal-eMagazine/Subscribe-to-Qpedia and see why over 18,000 engineers read Qpedia.

Did you know Qpedia also publishes a book series? The five volume set contains 248 in-depth articles, researched and written by veteran engineers. They address the most critical areas of electronics cooling, with a wide spectrum of topics and thorough technical explanation. Order Now.

How to Calculate Heat Loads for Liquid Cooling Systems

A series of calculations can be used to find the thermal loads in common liquid cooling systems. Calculations of this nature are needed to predict the performance of liquid cooling systems, which are effective but complex thermal management solutions. Several equations must be calculated to fully understand the behavior of a liquid cooled system, and ATS is providing these to engineers via personal instruction and in a paper available free from the company’s website, Qats.com.

IIn the paper, which appears in the company’s e-magazine, ATS considers a liquid cooling system as a closed loop system with three major components: cold plate, heat exchanger and pump. The cold plate is typically made from aluminum or copper, and is attached to the device being cooled. The plate usually has internal fins which transfer heat to the coolant flowing through them. This fluid moves from the cold plate to a heat exchanger where its heat is transferred to the ambient air via forced convection. The final part of the cooling loop is the pump, which drives the fluid through the loop.

A series of equations is provided to predict the final temperature of the device being cooled. The first of these equates the surface temperature of this device with the product of the power dissipated by the device times the thermal resistance of the cold plate (and its thermal interface material), added to the temperature of the water entering the cold plate.

The sequence of calculations factors in specifications from the cold plate, heat exchanger and pump. The result is a solution for the device temperature as a function of cold plate resistance. In the example cited by ATS, a cold plate thermal resistance of less than 18 degrees C/W is required to cool an Intel Xeon 5492 processor in a 25C temperature environment.

Liquid cooling is an important and expanding practice in the electronics industry. It is important to understand the impact on performance of all three major parts of liquid cooling loops (cold plate, heat exchanger and pump) to ensure an acceptable level of performance at the lowest cost.

Instructions for calculating load for liquid cooling systems are available on Qats.com in the pages of Qpedia, the thermal management emagazine from ATS. More information is also available by calling 1-781-949-2522.