Investigation of usable thermoelectric voltage generated by computer waste heat

Abstract

Computers use electric current to process information. Heat is generated in computer components whenever current flows through it, the heat generation causes unavoidable heat build up and a subsequent temperature rise at and around the components. High operating temperature is dangerous to the safety and reliability of components since the failure rate of computer components increases almost exponentially with the increase in operating temperatures. Similarly, the heat generation leads to wastage of energy yet there exist energy crisis in the world. Computer industries are building smaller and denser circuits to improve the computing power and portability. The main drawback of this miniaturization is the increase in the amount of heat produced per unit area of the component, so huge amount of money in the semiconductor industry is put towards thermal management. This study sought to determine the heat generated in a computer, the usable thermoelectric power that can be generated from computer waste heat and the reliability of using the generated thermoelectric energy to power the computer. Compaq P4, Compaq P3 and Dell P4 desktop computers were used for the study. The heat generation of the desktop computers under varying processor workloads was found by measuring the current and voltage from the PSU to the motherboard and HDD of the computers using a digital multimeter. Type J thermocouples were connected at the heat generation modules of the computers to convert waste heat in the desktop computers to thermoelectric energy. 2286/2285 data logger was used to make the measurements of temperature and the corresponding thermoelectric voltage generated from the thermocouples. These measurements were taken at room temperature. Compaq P4, Dell P4 and Compaq P3 generated heat at the rate of 286.33, 152.57 and 182.37 joules per second respectively. An optimum thermoelectric voltage of 11.583 μV, 9.889 μV and 7.269 μV was generated from the waste heat of Compaq P4, Dell P4 and Compaq P3 desktop computers respectively using thermocouples. Computers produce heat from which usable thermoelectric energy can be generated hence the heat produced by computers should be converted to thermoelectric energy.