Fewer Moving Parts As previously discussed, since thermoelectric coolers work electronically—using the Peltier elements to generate cooling -- the only moving parts are the fans used to circulate cool air throughout the enclosure. This provides a number of benefits when compared to enclosure air conditioners. With fewer active components, there is a lower risk of component failure and less required maintenance. Along with solid-state construction, this leads to higher reliability, lower maintenance costs and consistent cooling.
Fewer moving parts also produce less vibration, acoustic and electrical/EMI noise. Many applications that might be impractical for air conditioners or air-to-water heat exchangers because of noise or vibration concerns can be cooled effectively with thermoelectric coolers. For example, thermoelectric coolers are ideal for applications that involve high-precision processes, sensitive or intricate electronics, or integral sensors that are susceptible to vibration and noise interference.
Flexibility
Because of their unique design, thermoelectric coolers can many times offer greater flexibility for meeting the challenges of certain small-to-medium and HMI enclosure applications than conventional cooling solutions. A smaller physical size ( both in linear dimension and weight), thanks in part to limited internal components, creates an immediate advantage when compared to most air conditioners and air-to- water heat exchangers before the unit is ever turned on. This relatively small size—as small as 16 "H x 5 "W x 6 "D, weighing as little as 5 lbs -- allows thermoelectric coolers to be used in ways that other cooling devices cannot. Thermoelectric coolers can cool pendant arm-mounted and otherwise suspended HMI enclosures without dramatically affecting the weight load placed on the arm or pendant system. They can also be used in multi-unit configurations to deliver the required cooling capacity while providing previously mentioned advantages such as low noise and vibration. The self-contained, solid-state construction of thermoelectric coolers greatly enhances their flexibility as well. Thermoelectric coolers require nothing but a power source to operate effectively. They do not need chemical refrigerants (like air conditioners) that could potentially be harmful to the environment, nor do they require a chiller system connection to supply cool water like air-to-water heat exchangers. This absence of refrigerant or supplied water allows for near limitless mounting flexibility since thermoelectric cooler units can work in virtually any orientation including horizontally or at an angle without concern for liquid ( such as refrigerant, water, or oil) circulation or interference from external chiller connections or condensate hoses—all in direct contrast to the limitations of other cooling devices. Some thermoelectric coolers, like those made by Rittal, take the flexibility of thermoelectric cooling even further by giving users the choice of "external" or " internal" mounting in which the body of the unit lies either inside or outside the enclosure as shown in the pictures below. This can prove helpful in overcoming space-related issues and to ensure the freedom of movement for support and pendant arms. The final area of flexibility to be discussed in this paper is that of power. Thermoelectric coolers can operate with a wide range of voltages, and with either DC or AC power. For example, a unit could be rated for 24 VDC or 110 to 230 VAC. While a supply of DC power is necessary to generate thermoelectric cooling via the Peltier Effect, some industrial thermoelectric cooling units made by leading manufacturers, such as Rittal, feature built-in power supplies to facilitate the use of AC power and provide maximum flexibility to users.
Conclusions
There are several different types of cooling devices available to remove the heat from industrial enclosures, but as the technology advances, thermoelectric cooling is emerging as a truly viable method that can be advantageous in the handling of certain small-to-medium and HMI enclosure applications. As the efficiency and effectiveness of thermoelectric cooling steadily increases, the benefits that it provides including self-contained, solid-state construction that eliminates the need for refrigerants or connections to chilled water supplies, superior flexibility and reduced maintenance costs through higher reliability will increase as well. In an industry that is ceaselessly searching for better ways to cool enclosures, thermoelectric cooling is one option that users need to consider as they evaluate possible solutions for their application requirements.
