摘要 |
<p>A glass heating system (26) includes a low emissivity sheet of coated glass (34) and an optical sensor (28) mounted on the surface of the glass (34) for optically detecting condensation on the glass (36). The low emissivity glass (36) is economical to produce and provides superior thermal properties. The low emissivity glass (36) has improved thermal characteristics for use in insulating glass doors for freezers and refrigerators. The optical sensor (28) is positioned between the sheets of glass (34, 36) in the insulating glass unit (26) for detection of moisture on the outer surface. When condensation is detected, the controller (30) transmits power through the conductive coating on the unexposed surface of the glass (36) to heat the glass and eliminate the condensation. In a two paned insulating glass door (34, 36), the control circuit (30) can be conveniently mounted in the frame of the door (32).</p> |