Copyright Goodheart-Willcox Co., Inc. Chapter 12 Radiant Heating Systems 265 ■ ■■ Driveways ■■ Entry ramps ■■ Parking garages ■■ Aircraft hangars ■ Pool decks When combined with an efficient heating source system—such as geother- mal or solar thermal storage, snow and ice melt systems can provide an innova- tive and effective system that can work smarter, faster, and easier than conventional methods of ice and snow removal. 12.8.2 Designing Snow and Ice Melt Systems The design process for sizing snow and ice melt systems for both commercial and residential use can be planned by professional engineering groups or with help from system manufacturers. Software programs are also available to assist in system design. The process begins with an accurate heat-loss calculation to create optimum and efficient system performance. Designing these systems is a similar process to that of conventional radiant heating arrangements however, there are several differences: ■ ■ The designer must first determine the amount of snow that must be removed per hour based on the average snowfall for the given area. In snow and ice melting, there must be a change in state (solid to liquid). Therefore, the designer must calculate the Btu/hr output required to melt the proper amount of snow or ice at the required rate. ■ ■ The designer must determine the lowest outdoor design temperature at which the system will operate during the snow or ice melt phase. ■ ■ Once these criteria are determined, the designer must calculate the total Btu/hr required to accomplish the amount of snow and ice melt needed at design conditions. ■ ■ Snow and ice melt sensors must be strategically placed within the slab. When dealing with sloping pavement, areas at higher elevations will dry out faster, and the melted snow and ice will drain to lower areas. If the drier areas continue to be supplied with heat, the result will be large amounts of wasted energy and high operating costs. ■ ■ The designer should plan for moisture runoff and design a drainage system that will prevent melted snow and ice from accumulating on lower areas of the slab. In addition to these design points, take time to calculate the properly sized heating system (boiler) when determining radiant heating for snow and ice melting. Often, a dedicated boiler will be used for this type of application. Also, GREEN TIP Using Waste Heat to Keep the Sidewalks Clear In 1988, the city of Holland, Michigan, became home to the largest municipally run snowmelt system in North America. By using waste heat from a nearby power generating plant, water is heated and circulated through 120 miles of tubing underneath city streets and sidewalks. With water that is heated up to as high as 95°F, the system can melt snow at the rate of up to 1″ per hour—even at outdoor air temperatures of 20°F. By utilizing waste heat as its heating source, this sustainable system essentially provides free energy to the snow melt system.