Water-based central heating systems were originally developed in the late 1800s44. During that time, and for several decades to follow, there were no electrically powered circulators available. The only “propulsion effect” available to move water through systems was the differential pressure created by the simultaneous presence of hot and cool water. Hot water in the...

INTRODUCTION: Every heating system affects the health, productivity, and general well-being of numerous people over many years. The ability of that system to provide thermal comfort is of paramount importance and should be the primary objective of any heating system designer or installer. Most people appreciate a warm comfortable house on a cold winter day....