In some cases, the heat dissipation from the inside of the cabinet to the ambient is difficult, e.g. for control cabinets in fire protection zones, in which the control cabinet wall must not be breached, or for control cabinets that are operated under a protective hood.
Active cold side is located inside the cabinet and passive cooler is located outside of it.
In cases of normal control cabinet cooling, a cooling device is installed into a sidewall or into the roof of the cabinet. In some cases, the heat dissipation from the inside of the cabinet to the ambient is difficult, e.g. for control cabinets in fire protection zones, in which the control cabinet wall must not be breached, or for control cabinets that are operated under a protective hood. In these cases, the heat must be transported out of the control cabinet in another way.
The Peltier-technology offers a very good solution for this: The separation of the hot and cold side into two individual devices which are connected by a fluid flow. This fluid, transported through hoses or tubes, can simply be led in and out of the cabinet together with the electrical supply lines through the regular cable entry.
Basically, there are 3 options for building such a system:
Option 1: the "active" cold side is located inside the control cabinet and contains the Peltier-modules. A fluid-heat-exchanger forms the hot side of this part. A passive heat-exchanger (fluid-to-air) forms the second part of the system and is located outside of the cabinet. This option is the most versatile and the easiest to implement.
Option 2: the passive cold side is located inside the control cabinet, i.e. the cooler transports the heat from the interior air of the cabinet into the pre-cooled fluid. The active cooler is located outside the cabinet and forms the hot side of the system. This option involves the problems of transporting the cold fluid over long distances and requires hoses or pipes with good thermal isolation.
Option 3: both components, inside and outside the cabinet, are active coolers. This option is preferentially applicable in cases of high ambient temperatures and high temperature differences between the air inside the control cabinet and the ambient air. However, the efficiency of such systems is not optimal, and the effective power is limited.
Active re-coolers (hot side) which are located outside the control cabinet, if necessary, can be installed outside the protected zone in which the control cabinet is located.
The main fluids used are liquids due to their higher specific heat capacity and incompressibility. Water is the easiest solution, but inside a control cabinet there is a risk of leakage and an associated damage. As an alternative, oils or electrically non-conductive liquids could therefore be considered. Gases are also conceivable but reduce the performance of the system. A pump installed into the circuit provides the necessary fluid flow.
Such two-part Peltier cooling systems, like one-part systems, offer all the advantages of this technology, such as the possibility of cooling and heating, operation in extreme environmental conditions such as dust loaded ambient air, salt mist, high ambient temperatures, or mechanical influences such as acceleration forces or vibrations.
Two-part Peltier systems, however, must always be individually designed to meet the customer requirements and therefore are almost never standard devices.
Talk to Europeltier about it! We can develop your temperature management project from the first free evaluation to the prototyping and series production of your temperature control system.