1. Characteristics of Conventional Heating Technologies

A significant amount of global energy consumption is used for space heating and water heating; due to the expeditious urbanization in developing countries, energy consumption is increasing rapidly. In this chapter, the current energy usage distribution for different heating applications is presented. A review of the characteristics of conventional heating technologies are presented herein along with the proposal of a couple of advanced technologies to enhance heating efficiency. It is observed that the energy efficiency in fuel-based heating technologies could be improved by (a) upgrading/replacing the boiler, (b) condensation heat recovery from cogeneration, or (c) waste heat recovery from flue gases. Widely used vapor-compression heating systems include air source heat pumps and ground source heat pumps. However, only in a few cases could the technologies improve the energy efficiency of the heating systems and that too by a limited extent. Accordingly, there is still scope for further improvements in energy efficiency of the heating systems.