How Much Snow Can a Heated Driveway Melt?

System Types

• Driveway heating systems come in two general types. In an electric system, resistance cables embedded in or under the pavement heat up when power is turned on, warming the pavement and melting the snow. "Hydronic" systems circulate hot water through pipes embedded in the pavement, achieving the same mission. In both types, spacing of the grid, size of the wire or pipe, and depth of installation affect performance. Electric systems are generally more cost effective on small projects, while long driveways and large parking lots are usually done with hydronics.

System Activation

• In an automatic system, when sensors detect near freezing temperatures and precipitation, a switch is triggered, turning the system on. Matt Carter, design consultant for radiant heating manufacturer WarmZone, Inc., explains that an electric system gets the pavement warm faster. A hydronic system has to heat its boiler before it can start circulating warm water through the pavement. Even with that delay, Carter explains, a hydronic system will catch up quickly and keep the pavement clear. A system can be installed with manual switching instead of automated sensors. While less expensive, if no one is home to flip the switch when the blizzard blows in, the driveway will be covered.

Sensor Designs

• Sensor design and placement influences system performance, as well. The controller will start the system whenever sensors detect ambient temperatures below 38 degrees and falling precipitation. For typical homeowner installations, an elevated sensor works perfectly. However, areas subject to blowing and drifting benefit from sensors embedded in the driveway itself. Embedded sensors monitor tricky conditions exactly where they are most important. Elevated sensors might fail to start the system when the snow is blowing instead of falling from the sky.

After the Storm

• After the storm, you have to pay the bill. Typical estimates of operating cost run between 28 cents and 50 cents per hundred square feet per hour. For a suburban home with 50 feet of driveway 12 feet wide and a pad wide enough for two cars in front of the garage (24 feet by 24 feet), a snowstorm that lasts four hours would cost around $30 to clear, assuming the 50-cent operating cost and about one hour of run time after the snow stops falling, to dry the pavement thoroughly to prevent ice.