Copyright Goodheart-Willcox Co., Inc. 264 Hydronic Heating: Systems and Applications Snow and ice melt systems work as follows: An effective system detects snow and ice buildup on outdoor surfaces by means of an in-ground sensor. This sen- sor sends a signal back to the controller, which opens hot water valves located at the radiant system manifold. The heated fluid from the heating source warms the surface using PEX or PE-RT piping embedded in the concrete, sand, or asphalt. This in turn melts the snow and ice, keeping the area clear at all times. When installed properly, snow and ice melt controls should protect the heating equipment at all times from damage due to extreme temperature fluctuations as well as protect the outdoor surfaces from repetitive freezing and thawing cycles. The in-ground sensors should detect the actual conditions on snow and ice melt surfaces to ensure that melting begins when the snow starts to fall. These sen- sors should also activate the system to cycle off as soon as they detect that the outdoor surface is dry, Figure 12-51. This will optimize the system’s energy efficiency by not allowing the boiler or heat source to run longer than necessary. 12.8.1 Applications for Snow and Ice Melt Systems Snow and ice melt systems are often requested by customers looking to meet various health, environmental, and safety standards, such as the requirements set forth by the Americans with Disabilities Act (ADA). Customers also want to install these types of systems to protect themselves from lawsuits and liability resulting from slip and fall injuries. Snow and ice melt systems can be effectively used in a wide selection of applications:■ ■■ Sidewalks ■ Entryway steps City of Holland Figure 12-50. Snow and ice melt systems provide an effective method of keeping sidewalks, driveways, and even roads clear. ND700/Shutterstock.com Figure 12-51. A good snow melt system will cycle off as soon as it detects that the outdoor surface is dry.