Hydronic in-floor radiant heat systems are known in the prior art. Such radiant heating systems utilize tubing within a floor structure to carry and disburse heat through the floor without any visible radiators or heating grills. They generally do so by embedding tubing in a single continuous horizontal concrete slab poured below the finished flooring. Warm water is then circulated through the tubing and the heat in the circulated fluid flowing through the tubing is transferred to the concrete slab by conduction. The concrete stores and radiates the heat, thereby warming objects in the room, rather than the air in the room, which can be more cost effective and can reduce heat loss.
It is known that such systems can be formed by providing a subfloor, running tubing over the subfloor, and then pouring a single continuous concrete or gypsum slab, such as Maxxon Corporation's THERMA-FLOOR®, around and over the tubing. A synthetic material is generally used for the tubing, such as polyethylene or polybutylene, which has the advantage of not expanding and contracting with fluxuations in temperature. When the concrete or gypsum hardens, it acts as the thermal mass for the system. The concrete or gypsum underlayment or slab is poured in liquid form across the entire surface area and cures to encase the tubing.
However, such systems have a number of drawbacks. First, the equipment required to pour the concrete slab is extensive and the process for installing the slab involves pumping the concrete through an elaborate delivery system, often at great effort and expense. Second, delays in construction are necessary to allow the concrete slab to set-up or cure. Third, the choice of materials that may be used as the thermal slab are limited. Fourth, the conditions in which the concrete slab cures or is formed varies from job site to job site and is dependent in large part on weather conditions. This can result in variations in the strength and characteristics of the slab. Fifth, because the underlayment is a continuous planar slab, if there is leakage in the piping or problems with the subfloor, the entire slab must be removed and replaced. Sixth, it is often difficult to properly align and then maintain the alignment of the piping when the slab is being poured and is curing.
Hence, it would be useful to provide a radiant heat system which allows for quick and easy installation, uniform characteristics and strength in the underlayment, uniform fabrication, options in the characteristics of the underlayment, greater standardization, and easy repair.