When it comes to heating and thawing large outdoor areas, there are usually three or four methods to choose from. Gas (propane), Hydronic (glycol), Chemical (salts), or my personal favorite – Electric Heat (RapidTHAW & CureMAX Concrete Thermal Blankets and Powerblanket). Although all four methods may seem reasonable solutions for heating and thawing, closer examination concludes that the heated ground thaw and curing blankets are a superior technology for delivering a barrier of heat to large areas of frozen ground and ice. Let’s take a closer look by examining the other 3 first-
Propane Ground Heaters are simple infrared or “open flame” systems that that direct heat to frozen soil and ice.
While propane heaters have limitations, they are fully portable and best suited for smaller footprint projects. They are specifically designed for grave plots, fence posts, concentrated square-footage utility projects, and construction footings.
Unlike other ground thawing equipment meant for larger surface areas, propane ground heaters can be easily transported and set-up for operation by 2 people. They require no more than one 20# propane cylinder for 24 hours of operation; no electricity, coolant, generators, or extensive manpower needed.
Two of the more popular systems are the “Bubba Burner” and the “Thaw Dawg” http://www.groundspecialties.com
Portable hydronic heaters were originally introduced about 12 years ago to the construction market as ground thawing equipment. They were designed to help contractors stay busy through the frozen winter months by taking the frost out of the ground. But industrious contractors soon learned that hydronic heaters could be used to allow concrete pouring through winter as well. As concrete cures, it puts out heat. The warmer the concrete, the faster it cures. When it’s frozen or very cold, concrete can stop curing altogether.
Park the trailer close to the area you want heated and start up the boiler to begin heating the glycol solution. The boiler uses propane or diesel to eat the glycol and stores it in an insulated holding tank. Lay out the hoses in a snake-like pattern with rows two to four fet apart depending on the amount of heat desired. Attach both ends of the hose to the distribution manifold on the trailer to form a continuous loop. Cover the area with insulating blankets to maximize the heating effect and avoid heat loss. Open the valve and let the heated glycol solution start to flow.
When you add salt to water, you introduce dissolved foreign particles into the water. The freezing point of water becomes lower as more particles are added until the point where the salt stops dissolving. For a solution of table salt (sodium chloride, NaCl) in water, this temperature is -21°C (-6°F) under controlled lab conditions. In the real world, on a real sidewalk, sodium chloride can melt ice only down to about -9°C (15°F). Also take into consideration what happens when you add all those chemicals into the water table, and you soon start to realize how ineffective and harmful salts can be.
Our favorites for this category of thawing and curing go to Powerblanket. Their technology uses an internal heat spreading matrix to transfer heat to large areas of frozen ground and curing concrete. Their designs allow low amounts of electric energy to be transferred into heat energy which is transferred to these heat spreading materials. When applied to frozen ground or curing concrete, the results are phenomenal. Roll it out, plug it in, and these heated pads thaw on contact – delivering a barrier of warmth to any surface. Water & snow resistant and welded seams for water tight winter operation. Powerblanket offers their products in both 120V & 220V and come in sizes up to 25 feet in length (the largest heated blankets in the industry). Honorable mention goes to RapidTHAW for their low cost options for tight budgets.
Cold Weather States with the greatest demand for ground thawing: