Design, built and testing of a controlled temperature box

Abstract

This paper presents the design and built of a temperature controlled box by utilizing a thermoelectric module. Thermoelectric module is a heat pump that can provide either heating or cooling, depending on the polarity of the applied potential difference across the module. The module is essentially built from a series of semiconductors, sandwiched by ceramic layers as electrical insulator. It is usually used in the heating and cooling application with the power less than 100 W. A temperature controlled box for the temperature range between 15 and 40 °C, with the size of 220 mm x 220 mm x 300 mm was designed, built and tested. The box was properly insulated so that the maximum heat gain/loss was far less than 58.6 Watt. This box used thermostatic temperature control. The direction of polarity of potential difference was controlled using a switch. Thermoelectric module was supplied with 14.9 Volt of potential difference and 2.5 Ampere of electrical current. The temperature inside the box can be maintained within 1.5 Kelvin of the set point temperature in cooling mode, based on three different measurement points in the box. A fan was used to circulate the air inside the box. This temperature controlled box could be used in medical applications where the storage of vaccine and blood may require lower temperature but they should be heated to about the body temperature before they can be injected or transfuse to the patient