What to Consider When Choosing a System
Who is Using Snow Melt Systems and WhySnow melting systems are popular for both commercial and residential use. Here are some common applications:
- As a convenience. Owners of upper-end homes install the systems in all their exterior slabs--including driveways, sidewalks, steps, and patios--to completely eliminate the need for shoveling.
- To target trouble spots. Homeowners who cant afford to install the systems in all their exterior concrete slabs use them only where snow and ice accumulation poses a problem, such as in the wheel tracks of a driveway, in the front walkway and steps, or in driveways with steep inclines.
- To reduce snow removal costs and liability. Business owners use the systems in outdoor malls, parking lots, car washes, walkways, and loading ramps to eliminate the expense of snowplowing and to prevent slip-and-fall accidents.
Costs to Install and Operate Snow Melting SystemsThe costs to operate snow melting systems vary widely depending on the size of the area being treated, local utility costs, the average total hours of snowfall, and how fast the system user wants to melt the snow. Obviously, the larger the area being heated and the more snow there is, the higher the operating cost. Also, a system used in a colder climate may require a higher wattage (for electric) or more Btu (for hydronic) than a similar system used in a warmer climate.
Watts Heatway, a supplier of hydronic systems, says annual operating costs range from 12 to 25 cents per square foot. So on average, it would cost $120 to $250 each winter to melt snow off a 1,000-square-foot driveway.
Depending on local utility rates, electric systems may cost even more to operate. EasyHeat, a supplier of electric mats for snow melting applications, says that the seasonal cost to heat a 1,000-square-foot slab at 50 kilowatts will run about $276 in areas of light snowfall (50 inches per year or less) and $692 in areas with average snowfall (50 to 100 inches). Those estimates are based on an average kilowatt cost per hour of 6.92¢.
Material and installation costs vary widely too. For Warm Floor Centers electric system, the materials alone run $4 to $6 per square foot, according to Blackburn. Lee Hydronics system runs about $5 to $10 per square foot installed. "The biggest variable is how far the embedded tubing is located from the power source," claims Bailey. The farther away the utilities are, the higher the installation and operating costs.
Factors to Consider Before Choosing a SystemContractors and their customers must consider many factors before choosing the type and size of snow melting system thats best suited for a particular application. A system design that works well in one city may be inadequate in another.
"Not all snow melting systems are created equal," says Larry Drake of the Radiant Panel Association, an organization for radiant heating and cooling contractors, wholesalers, and manufacturers. He offers the following tips for making wise planning and selection decisions.
- Utility costs and availability.
- The cost and availability of utilities vary widely nationwide. The owner should consider the cost of electricity versus other power options such as propane, oil, natural gas, and solar. "With an electric system, the only utility you can use is electricity," says Drake. "With an hydronic system, you can use whatever power source is available, be it natural gas, propane, solar, or even electric."
- Space availability.
- An electric system simply plugs into a junction box. For an hydronic system, the owner must have the space to accommodate the water heater or boiler, circulating pump, and manifold.
- User expectations.
- Does the owner expect the driveway or sidewalk to be free of snow at all times, or is gradual melting within a few hours after snowfall acceptable? The former will result in higher equipment, installation, and operating costs.
- Have provisions been made for where the melted snow is going to drain? In some cases, a drainage system may need to be installed, especially if heavy snowfalls are expected.
- If the snow melting system is to be installed in an existing slab, its easier to retrofit an electric cable because it has a smaller diameter. "You can groove the concrete and lay the cables in the grooves," says Drake. For hydronic tubing, more concrete removal is required.
- A hydronic system typically requires more maintenance. In addition to maintaining the boiler and pump, "you must inspect the propylene glycol fluid levels periodically, just like the antifreeze in a car," explains Drake.
Resources for Contractors to Learn More about Snow Melt SystemsEven though a snow melting system can cost several hundred dollars each winter to operate, it may be cheaper than snow-removal equipment, plowing services, and expensive de-icing chemicals, especially in areas of heavy snowfall. But in order for these systems to run efficiently and provide their full benefits, they must be installed properly. Contractors who want to learn more about these systems and the installation process can get help from the following sources:
- System suppliers often can provide detailed design guidelines and free computer-aided design services to help contractors lay out and install the tubes properly.
- The Radiant Panel Association offers honeowner tips for the design and installation of residential radiant heating systems.
- Uponor (formerly Wirsbo) offers extensive training programs for both its plumbing and radiant floor heating systems, with classes ranging from two hours to two and a half days. Uponor's Home Comfort Team program is nationally known as the best place in the U.S. to learn about the proper design and installation techniques for radiant floor heating. Since 1993, more than 4,000 heating contractors have been through our two day Home Comfort Team program at our Apple Valley, Minnesota headquarters. These HCT members are the best and brightest radiant installers in the industry.
- The 1999 HVAC Applications Handbook, published by ASHRAE, contains a chapter on both hydronic and electric snow melting systems. Topics include heating requirements, system design, pavement design, and controls. The chapter can be purchased at the ASHRAE Web site for $39.