Last month we took a look at the state of the art—past and present—in gas, oil and hydronic space-heating systems, focusing on the practical applications of each. With this issue, we delve into the second and final part of this heating overview with a discussion of electric, solar and solid-fuel systems. Electric Heating Systems Electric heating systems come in several forms. The most common is electric baseboard resistance. In spite of the inherent inefficiency of electric heat, all things considered, electric baseboard makes sense as a back-up system in energy-efficient, tight houses—primarily those heated with solid fuel. In addition to its low initial cost, it is very flexible, allowing easy use in individual rooms without expensive zone