Overview of several novel thermodiode designs and their application in buildings

Based on the working principle of thermosyphon, several thermodiode designs, which allow heat to be transferred in the desired direction but block the heat flow in the opposite direction, were put forth for analysis and discussed for solar heating applications. Particularly, the recent development of thermodiodes with an easily alterable direction of heat flow, so-called bi-directional thermodiodes, was introduced and their performances examined and optimized for both summer-cooling and winter-heating of buildings. Presented in this paper is a review of single-phase thermodiodes applied to solar energy utilization and energy-efficient buildings.