Roads, footpaths, garages, driveways, walkways, loading docks, ramps, hospital and shopping-mall entranceways, bridges, helicopter landing pads and more — many traffic areas have to be kept snow- and ice-free around the clock in winter so people can walk and drive with ease. For this tough application, snow-melting cables and mats offer a perfect solution. They provide safe thawing of snow and ice and prevent snow build-up and ice on surfaces. They are normally used with snow (moisture) and temperature sensors and a thermostat, which switch the power 'on' and 'off' to keep the area clear of snow and ice. The system is operated from a control box or panel installed indoors.
The heating cables are also available as a complete pre-assembled item with a cold lead, or made in the form of a mat that is easy to roll out and install. The cables can be secured directly onto the reinforcement steel before the sand bed, concrete or asphalt is poured. The mat is designed to heat walkways and driving tracks, and it can be cut and turned around for easy, quick installation under cobble stone or other outdoor coverings.
Different types of snow-melting cables are:
1. Single-core heating wire with double cold leads attached at the ends; insulation of fluoropolymer or polyethylene, copper braid or Al-foil shield and high-temperature PVC jacket; rated about 30 W/m @ 230 V. Installed at about 100 mm spacing, it gives a heat output of about 300 W/sqm.
2. Dual-core heating cable with a single cold lead attached; insulation of fluoropolymer or polyethylene, copper braid or Al-foil shield and high-temperature PVC jacket; rated about 30 W/m @ 230 V. Installed at about 100 mm spacing, it gives a heat output of about 300 W/sqm.
3. High-temperature dual-core heating cable with a single cold lead attached; insulation of fluoropolymer or polyethylene, copper braid or Al-foil shield and a double jacket of polyethylene and high-temperature PVC; rated about 30 W/m @ 230 V, for installation under asphalt with a heat output of about 300 W/sqm.
4. Roof & gutter heating (self-regulating type): it automatically varies its power output in response to temperature change. It is easy to install and can be cut to any length; insulation PE, jacket TPE, maximum heat output 40 W/m. A circuit breaker must be used. These are much costlier.
After installation under concrete or asphalt, all cables and mats require no maintenance and serve effectively for years. They usually come with a minimum 10-year warranty. Professional advice on cable/mat selection and proper installation is generally available from the seller or installer.