Radiant heat is becoming increasingly popular in the United States, although some people are worried about how much it will cost them to install radiant heat in their homes. The cost does vary, depending upon the type of radiant heat system you install, and the number of rooms you install radiant heat devices in. Installing a radiant heat unit on an already-built concrete floor has a number of disadvantages, and one of them is the expense of this installation.
Installing on Concrete
Concrete is exceedingly good at conducting heat. In fact, it is often used when installing radiant heat flooring, as it both supports and protects the tubes or piping used in radiant heat. However, because of this conductivity, when you place your heating panels on a concrete floor, the heat can actually be diverted downwards, perhaps heating up a basement, or the room below. This by itself is very costly, as it can inhibit the energy savings that most customers consider to be the main advantage of radiant heat systems. Another important question is whether you can install your radiant heat system onto an already-existing floor, or whether you will need to dig now, shore up the sub-floor, and then add more concrete to create the right thermal layer for your need.
The best solution to the problem of concrete conductivity is to lay some insulation over the top of your base concrete floor, and use this as the subflooring for your radiant heat. Insulation does not always cost a lot, but getting enough of it to cover a large floor, plus the backerboard and mortar needed to secure it all, and it can become quite expensive. Colder states will need a thicker insulation material than in warmer areas, so costs of insulation can vary. The price of installing a basic hydronic radiant heat floor is around $6 per square foot, but of course this can assume a much greater expense once additional layers of insulation and protection are included.
If you are installing your radiant heat tubing on top of a concrete surface, you will need to add some insulation in order to prevent the heat from traveling downwards. Tubing should be no less than 2 inches from the surface of the floor you intend to heat, so if your subflooring is deeper than this, you will need to add a thick layer of insulation in order to protect your floor. You will also need to add protection to the bottom of any metal furniture, as this can absorb all of the heat from the floor, making the rest of the room cold and the metal surface very hot.
One of the best things about using radiant heating with concrete floors is that, assuming the concrete is thick enough, you can heat the floor during times when the electricity costs less. These off-peak times usually fall between 9pm and 6am, and the heat stored in the floors during this time is gradually released over the next few hours. This means that you can heat the room for a good portion of the day without having to pay peak heating costs.