Hospital entrances. "Because they are usually considered critical systems," says Whitworth, "these snowmelting systems are most frequently 'idled' during the winter months—continuously operated at a reduced output—to decrease system lag time." That minimizes the time required for the system to reach full operating temperature and start melting snow after sensors detect precipitation.

Parking garage ramps. Snowmelting systems ensure that cars driving in from the street can safely negotiate up and down parking garage ramps. System sensors are usually placed away from the ramp so that they can detect snowfall or precipitation, and temperature.

Loading docks and ramps. Here, moving the goods is the essence of business. Another good application for snowmelting systems.

Operating systems
On-off operation. Some snowmelting systems operate only when there is ice or snow. These on/off systems work in the presence of precipitation when the ambient temperature is below 35° F. While less costly to operate, these system take longer to start melting ice and snow because they must first increase the temperature of the slab.

Idled operation. In order to help systems respond faster, some systems are idled—or operated at reduced output—until precipitation is sensed with a temperature below 35° F to 38° F, when the system is operated at full output. These systems permit faster system response, and no snow or ice accumulation is permitted.

Sophisticated controls. Automatic controls that sense slab temperatures, outdoor temperatures, and precipitation can also be used. They're more costly, but allow greater system control.

System cost
Snowmelting systems themselves are not that expensive to operate, especially the on/off types because, typically, they operate only a few times a year. The biggest cost with a snowmelting system is the upfront price.

"Considering the cost of insulation, tubing, boiler, and pump system, and all installations, a snowmelting system will usually cost between $6 to $12 per square foot, with commercial systems at the higher end," says Whitworth.

Operating cost
On/off system. This is the cheapest system to operate. As an example, a Class II system in Buffalo, N.Y., may cost about $0.21 per square foot per year. The same system in Chicago may only cost $0.12 per square foot per year. Minneapolis or St. Paul may be in the range of $0.25 per square foot per year.

Idled system cost. Because it may operate any time the temperature is below 38° F, it will clearly cost more to operate these systems. Considering that it may operate for up to a third of the year (about 3000 hours), the total system energy would be 300,000 BTU per year. Hospitals may have waste heat from steam or condensation that may be readily available, greatly reducing or eliminating energy needs.

Conclusion
Icy surfaces are no longer a threat. Home or facility maintenance costs are reduced because snowplowing is eliminated or reduced, and ice-melting chemicals that kill landscaping and degrade concrete aren't required.

The cost of the system is more than returned with one avoided lawsuit. Even insurers recognize the value of these systems by rewarding commercial building owners with reduced insurance rates.

So, whether you're melting snow for a sidewalk in Columbia Falls, Mont., or warming an emergency room entrance in Gnome, Alaska, a properly installed snowmelting system will easily do the job. CC