Throw away the shovel: Snow-melting systems are here!
If shoveling isn’t for you anymore, snow-melting systems might be a consideration for your home. Hydronic, or hot water snow-melting systems use a home’s boiler, which sends a hot solution of water and anti-freeze (glycol) through plastic tubing embedded within your sidewalks or driveway. And they work great.
Here’s what you need, and what you need to know before considering a snow-melting system.
Estimating & Sizing:
As a general rule-of-thumb, in the U.S. snow-belt, the energy required to melt snow and ice is approximately 150 btus per square-foot of slab.
If you’re trying to snow-melt 1,000 sq. ft. of slab, your boiler needs to produce 150,000 btus of heat-energy. Snow-melting a 300-feet driveway? Make room for a (pricey) commercial boiler — or hire a snow-plow.
Given the energy requirements required to melt snow, in most residential applications, snow-melting systems are usually practical for sidewalks and other small areas. Also, small areas can often be handled by the capacity of the existing boiler. Large areas may need a stand-alone boiler for the job.
In addition to a boiler, hydronic snow-melting systems require:
Control system: Controls can be operated manually (on/off), or automated, with outdoor temperature and precipitation-sensors. Viega makes a few different options that we’ve employed for nearly 10 years without a problem.
PEX Tubing: Cross-linked polyethylene (PEX) tubing is the most common medium to carry hot water through the slab. Flexible and durable, PEX is able to handle the expansion and contraction of a concrete or asphalt slab.
Heat-exchanger: To avoid freezing the tubing, snow-melting systems must be filled with an anti-freeze solution (typically a glycol-derivative). One must not allow this solution to enter the boiler. To keep the boiler-water and the snow-melt system from cross-contaminating, a heat-exchanger is required; either a plate-style or shell-and-tube model.
Maintaining snow-melting systems:
The boiler that powers a snow-melting system should be cleaned and tuned — annually for oil-fired boilers, every other year for gas and LP. On an annual basis, one must test the PH of the antifreeze solution and maintain much like one does to a car’s coolant system.
Cost:
Costs of installing a snow-melting system can vary widely, depending on whether a new boiler is needed, the sophistication of the controls, and the size of the area to be heated. That said, expect to pay a professional $1,500 – $3,000 to install a high quality heat-exchanger and control system, and $2.00-$4.00 per sq. ft. to install tubing.
For more information, visit: www.enhancedliving.net
About the Author
John Bishop is vice president of Enhanced Living (www.enhancedliving.net), heating, cooling and indoor air quality specialists based in the Albany, NY-area. Extensive experience in the field of building science and residential energy-management, John was formerly the state marketing coordinator for New York’s award-winning Home Performance with ENERGY STAR and New York ENERGY STAR Labeled Homes Program.
