Snow-melting systems, installed in walks, driveways, loading platforms and other paved areas, are an efficient, economical means of snow, sleet and ice removal. To warm the surface, a 50-50 solution of water and antifreeze is circulated through copper tube embedded in the concrete or blacktop. Considerable savings can be realized at industrial plant installations where waste heat sources can be utilized.
In general, installation of snow melting coils is similar to that of floor panel heating coils. Selection of a sinuous or a grid pattern for a snow-melting system depends largely on the shape, size and installation conditions. Grids are good for square and rectangular areas; sinuous coils are usually preferred for irregular areas. The lower pressure loss with a grid configuration permits the use of smaller diameter tube saving material costs. Maximum economy is often realized with a combination of sinuous and grid-type coils.
Soft temper copper tube is suitable for both sinuous and grid-type coils; hard temper is better for larger grid coils and for mains. Soft tube facilitates the installation of sinuous coils because of its long lengths and ease of bending which reduce the number of joints to a minimum.
The solution temperature entering the snow melting coils should be 120°F to 130°F. To obtain a heating effect for snow melting of 100 BTU per hour per square foot with copper tube spaced on 12-inch centers in concrete (or 9-inch centers in blacktop), a maximum of 140 feet of ½-inch tube or 280 feet of ¾-inch tube may be used. To obtain a heat input of 200 BTU per hour per square foot of snow area, a maximum of 60 feet of ½-inch tube or 150 feet of ¾-inch tube may be used.
Tube in concrete should be located about 1¼ to 1½ inches below the surface. The concrete should be reinforced with wire mesh. In blacktop, 1½ inches minimum of compacted thickness of blacktop should cover the tube. The tube should be laid with care on compacted gravel, crushed stone or a concrete base. Allowances should be made for lateral movement where the tube enters and leaves the concrete or blacktop.
The same types of heaters and circulating pumps available for radiant heating installations are suitable for snow-melting panels. The panels also may be hooked up to a building's space heating system, if the system has sufficient capacity for the additional load and satisfactory precautions against freezing can be made.