Insulated jackets for hot and cold piping systems and for hot and cold air ducting systems and methods of use

A method of heat insulating a duct of a heating or cooling air distribution system comprising the following steps,

• providing a heating or cooling system for heating or cooling air,
• providing ducts to carry the heated or cooled air from the heating or cooling system to rooms,
• providing an insulation system formed by a thin jacket made from plastic material as part of the duct,
• forming the jacket from an inner wall, an outer wall and spacers connecting and spacing the inner and outer walls,
• the inner wall forming the duct which carries the heated or cooled air,
• choosing the jacket material thickness such that the insulation value of the jacket material is insignificant relative to the overall insulation value of the insulation system,
• forming an air space around the duct by the use of the outer wall and spacers within the jacket abutting the duct to allow for the formation and maintenance of an air space between the outer wall and the duct, the air space forming substantially all of the insulation value of the insulation system,
• omitting other kinds of solid insulation from the air space,
• forming the jacket from longitudinally extending segments,
• joining the segments to each other along longitudinally extending joints, and
• sealing the longitudinally extending joints.