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Take Control of Wintery Weather with Hydronic Snow and Ice Melting

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By applying radiant heating technology to outdoor surfaces, hydronic snow and ice melting (SIM) systems provide a safe, reliable, and cost-effective way to keep surfaces clear of snow and ice. From the driveways of private residences, to the sidewalks and streets in pedestrian zones, to bridges and helipads, many facilities can benefit from automatic SIM systems.

Here’s a quick overview of installation considerations.

Insulation: Without proper insulation below SIM areas, downward energy losses can exceed 50%. Suitable insulation is an outdoor-rated extruded polystyrene (XPS), polyurethane (PU), or expanding foam, rated R-5 at a minimum to R-10 for better response time.

Pipe Size and Spacing: To handle the required flow rates, 3/4 inch PEX piping at 8 to 9-inch spacing is typically used. Larger projects may require 1 inch piping, while ½ and 5/8-inch piping are used when tighter spacing or low profile is required.

Stairs: To ensure even melting and rapid response, piping must be spaced tightly and placed within 2 inches of the surface and the nose of each step. Typically, 1/2 inch PEX piping is affixed to the framework before pouring the stairs. For existing or pre-cast concrete steps, piping can be anchored on top of the structural concrete and embedded within an overpour.

Drainage: Effective drainage from the SIM area improves safety and reduces operating costs by not requiring the SIM system to evaporate the moisture. Drains are especially important at the bottoms of steps or ramps. The ground surrounding the drains should be heated and run-off should be directed to avoid creating hazards or ice dams on unheated areas.



Manifold Placement: Distribution manifolds that supply warm glycol to the SIM piping circuits are often located close to the SIM area, but far from the heat source. This is accomplished by designing an outdoor vault that protects the manifold and pipes, while allowing good drainage through an open bottom. Buried pre-insulated PEX pipes transfer the heated fluid between the heat source and manifold with minimal heat loss.

Hydronic SIM can be integrated in almost any outdoor surface. To ensure your SIM installations go smoothly, be sure to seek out manufacturer training and design services. You can find many additional SIM resources on our website at

Jon Bittenbender
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Posted In: ACCA Now, Hydronics

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