HTHW (HOT TEMPERATURE HOT WATER)

High temperature hot water (HTHW), medium temperature hot water (MTHW) and low temperature hot water (LTHW) systems benefit similarly to steam distribution systems in that underground heating lines are almost always visible with infrared imaging, even when no notable problems exist. This is due to the fact that no matter how good the insulation, there is always heat loss from the lines which makes its way to the surface. Problem areas are generally quite evident, having brighter white IR signatures that exceed the norm.

Chilled water supply (CHWS) and Chilled water return (CHWR) lines are usually cooler than the surface temperature and can be surveyed for thermal loss and leaks as well. Chilled water supply (CHWS) and Chilled water return (CHWR) lines are usually cooler than the surface temperature and can be surveyed for thermal loss and leaks as well, with an associated degree of difficulty in surveying because of the declining temperature difference to that of surface.