In-slab hydronic heating systems can eliminate several of the unpleasant aspects of winter. Embedded in a concrete slab or overlay, these systems take advantage of concrete's heat transfer capabilities, turning the entire slab surface into a radiant heat source. A network of closed-loop, insulated tubing circulates hot water or water-glycol solutions throughout the slab. The heating liquid for both indoor and outdoor systems can be supplied by almost any heat plant that produces low to moderate water temperatures. Used in concrete floors, hydronic systems heat rooms evenly and consistently. Used in outdoor slabs on grade, hydronic systems melt snow and ice, keeping pavement surfaces dry and safe. They also eliminate potential damage to concrete caused by snow removal equipment and corrosive deicers.
About 5 years ago, hydronic heating systems using elastomeric tubing were introduced in the United States. Elastomeric tubes bend easily to conform to almost any layout pattern, which speeds installation by minimizing the need for joints. They resist chemicals and corrosion and do not become soft at high operating temperatures or brittle at low outdoor temperatures. Because of their resiliency, elastomeric tubes also withstand impact. Elastomeric tubes are made of polybutylene, polyethylene, or other polymers and have a minimum service life of 30 to 50 years. Material costs for hydronic heating systems vary widely, ranging from one dollar to 14 dollars per square foot of floor area.