John Vastyan is president of Common Ground, Uncommon Communications, Manheim, Pa. He specializes in communications for the radiant heat, hydronics, plumbing and mechanical, and HVAC industries, serving regional, national, and international business-to-business manufacturers and trade associations. He can be reached at 717-664-0535.

What goes in the system makes a difference

If you find yourself at work on a snowmelting system without inhibited glycol in it, there are key steps to take to ensure that you aren't introducing good fluid into a bad system. Factors that cause excessive fluid degradation include operating temperature, the amount of air or dissolved oxygen exposed to the fluid, system age, the construction materials, and the quality of the heat transfer solution, including proper dilution and maintenance, to name a few.

Using a poor quality glycol fluid can lead to serious corrosion problems. Any glycol can provide freeze protection, but only a properly formulated glycol, at the right concentration level and with industrial strength corrosion inhibitors can keep corrosion in check. All glycols can introduce the potential to thermally degrade or oxidize even when left alone in their original sealed container. Degradation proceeds even more rapidly when glycols are operating in a system.

Many system owners learn the hard way that not all glycols are capable of providing long-term protection of system components from corrosion. The old adage "Do it right the first time" holds true because it always costs more to correct a serious corrosion problem than it is to prevent it from happening.

Plain glycol solutions, because they lack corrosion inhibitors, can increase the threat of corrosion in a hydronic snowmelting system. Moreover, putting them into your system cold will eventually cost you far more than the initial fluid price. Uninhibited glycols are less expensive, but become an ongoing threat to your system components.

Heat, oxygen, chlorides, sulfates, metallic impurities, and other contaminants can increase the rate of corrosion in the system. Combined, these are likely to create unscheduled system shutdowns, maintenance issues, and reduced system life. Glycols produce organic acids as they degrade, especially when heated. If left in solution, these acids lower the fluid's pH.

Specially formulated industrial inhibitor packages used in some glycol-based fluids help prevent corrosion in two ways. First, the corrosion inhibitors actively make the surface of the metal less susceptible to corrosion. Second, they buffer the organic acids formed as a result of glycol oxidation to keep the fluid from becoming acidic.

What's the ideal boiler for a snowmelting system?

A snowmelting system is the ultimate challenge for a boiler. Considering that a large volume of ice cold fluids will rush in on it at start—up, a boiler for this has to a be tough. New on the block is a condensing boiler.

The ultimate tool for low and super-low liquid temperatures at start-up. The boiler's secondary heat exchanger transfers exhaust heat to warm liquids before they reach the primary heat exchanger. At peak efficiency, water vapor produced in the combustion process condenses back into liquid form to release latent heat. Its sealed combustion, positive-pressure design assures that the boiler can be installed in many environments, even outdoors. Without the need of room air for combustion, the boiler is not affected by limited air from within the building, or by negative pressures created by other equipment. These units can also offer up to 96% efficiency.

Radiant heat in and outside a concrete home

If homeowners choose a concrete home, then radiant heat is the way to go. Slab on grade, combining massive concrete walls and large, glass-enclosed areas challenges the best of conventional forced air systems.

In this Springfield, Mo., home, abundant Frank Lloyd Wright-inspired concrete acts as an effective thermal storage system. Even the finished floors, concealing a half-mile of radiant heat tubing, are the actual scored and colored slab. It provides optimal comfort and an attractive, easy-to-maintain floor surface. Installer Bob Rohr says that, combined with a substantial under slab insulation to minimize heat loss, the high efficiency system will provide unsurpassed comfort and low operating cost for years to come.

Weather-responsive controls and multiple zones allow the home office and guest rooms to be controlled separately in this 2800-square-foot home that includes some walkway snowmelting, a radiantly-warmed, sunken concrete bath, and a cascade that spills from the back of the house where water accents the mature property's sloped features.