An Active Thermal Wall Based on Thermoelectricity

This paper describes the basic principles of a new concept for an active thermal wall able to improve the current practice of design and installation of air conditioning for enclosed spaces. The wall is a translucent or transparent flat wall which separates two environments (indoor and outdoor environments) at different temperatures allowing for the control of the desired temperature in one of these environments. This objective is reached using thermoelectric modules imbibed between translucent or transparent materials, such as glass windows, allowing for the transport of heat between the two environments at different temperatures. The most important applications to which the new active wall would be aimed are included within the sector of the thermal conditioning of spaces and heat transmission controlled in industrial machines or environments, substituting the usual installations. Introduction The house of the future is a concept on the minds of many researchers from different technological fields in order to improve the quality of life and the services of existing houses. One of the main topics of these investigations is energy use and management in the house of the future. The temperature in a room is an important factor to control in order to guarantee a comfortable atmosphere [1],[2]. The increasing use of electricity for air conditioning demonstrates this assertion. This paper describes the basic principles of a new concept of an active wall for the house of the future able to improve the current practice of air conditioning design. This active wall is the object of a registered patent of the authors. The wall is a translucent or transparent flat wall which separates two environments (indoor and outdoor environments) at different temperatures allowing for the control of the desired temperature in one of these environments. This objective is reached using the active wall as a heat pump using the Peltier effect through thermoelectric modules [3] included between translucent or transparent materials, such as glass windows, allowing for the transport of heat between the two environments at different temperatures. The thermoelectric elements have to be supplied by a continuous electric current which can be obtained from conventional sources of electricity or from photovoltaic panels. The most important applications to which the new active wall would be aimed are included within the sector of the thermal conditioning of spaces and heat transmission controlled in industrial machines or environments, substituting the usual installations. This paper is organised as follows. First, a description about the active wall is presented. Next, its theoretical performance is analysed using finite element techniques. Finally, some experimental results are included. Description of the active thermal wall The active thermal wall consists of two main components: The thermoelectric chains The material where the thermoelectric chains are imbibed One thermoelectric chain is a set of aligned thermoelectric pairs connected electrically in series and thermally in parallel. The electrical connections between the thermoelectric chains can be in series or in parallel. In this last case, the electrical bridges have to have special dimensions in order to improve not only the heat absorption at the cool side and the heat dissipation at the hot side of the thermoelectric pair, but also to uniform the temperatures on both sides of the active thermal wall. In order to obtain a suitable structural integrity of the active thermal wall, these chains have to be integrated in an imbibing material where the following two different configurations are possible: • Configuration (a) in fig. 1. In this case the thermoelectric chains have some material imbibed which are the electrical bridges of the chains in direct contact with the environment. Thermoelectric chain Imbibing material Heat dissipaters plates