The most effective way of heating basement floors involves radiant heat. Embedded in the concrete or installed on the concrete. Traditional heating systems leave concrete floors cooler than the room because heat rises. Radiant heated floors warm the room from the bottom up.
What is Radiant Basement Floor Heating?
Radiant floor heating systems are installed in or on the concrete floor. The heat is provided by hot water running through Pex piping or electricity passing through heating elements. Radiant floor heat warms the floor and keeps the entire room warm without having forced air blowing.
Courtesy: Stack Exchange – Hydronic radiant basement floor heat hookup.
Heated concrete floors provide more benefits than just heat.
- Comfort. The entire floor is heated and distributes warmth evenly throughout the room. Cold and drafty floors are eliminated.
- Quiet. Silent operation.
- Energy Efficient. Usually requires lower thermostat settings. The heat stays in the lower half of the room.
- Air Quality. No dust, mold, or mildew blowing out of forced air heat vents.
- Maintenance. Can last for over 35 years with little or no maintenance.
Basement floor heating does have some disadvantages that should be considered before installation.
- Cost. More expensive than traditional heating systems or supplementary heat like baseboard heaters.
- Slow. Takes longer to heat rooms than traditional heating systems.
- Height. Could raise floor 1” – 2” when adding to an existing concrete floor. Will affect baseboards, casing, and door operation.
- Flooring Replacement. Existing floor covering will need to be removed before the heating system is installed and then replaced.
- Floor Coverings. Some floor coverings like heavy carpet and underlay act as insulation and will slow or prevent efficient heat distribution.
How Does Radiant Heat Work?
Radiant heated floors provide uniform warmth to an entire room. The floors are kept at a constant temperature. The warm air rises evenly throughout the room maintaining consistent warmth at each level. There are two types of basement floor heating systems.
1. Hydronic Radiant Heat
Hydronic radiant heat is a water-based system that heats the concrete subfloor which radiates heat into the room. Most heated concrete floors have Pex water lines installed during construction. Before the concrete floor is poured on two inches of extruded polystyrene insulation, the pipe is laid out in a 6” or 12” grid. Then a 4” concrete floor is poured.
Water lines can be installed in “zones” and then connected to a manifold. Each “zone” ideally heats an individual room or section of the basement floor–allowing regulation of temperatures. A pump moves hot water from a boiler or hot water tank through the pipes. Heat from the water is transferred into the concrete and returns to re-heated.
The same system can be used on top of existing concrete floors. Many existing basement floors do not have insulation under the concrete. Any new water lines installed over concrete should include insulation to prevent losing heat to the ground below. A 2” concrete screed can be poured over the pipes. Then the floor covering is installed.
Another option is to hammer out and remove the existing concrete floor. Then reinstall it with insulation, the in-floor heating system, and pour new concrete. This is a more effective heating option but can cost up to $50,000.00.
Installing in-floor hydronic heated basement floors is not a simple DIY project. In addition to laying out the piping properly, there are manifolds, supply lines, sensors, boiler–or hot water tank–and controls to be hooked up. Most of these systems are installed by professionals.
2. Electrical Radiant Heat
Most electric basement floor radiant heat systems are mats designed to roll out on top of concrete floors. They are ideal for individual rooms. Operating costs for electric heat are higher than for hydronic systems. The initial costs are usually lower.
Whole room mats are available online, from home building outlets, and directly from manufacturers. Some manufacturers will customize mats to fit the dimensions of each room. Insulation should be installed below the electrical mats to ensure the heat gets into the room and not the concrete and dirt below.
Depending on the type of floor covering being installed, most electric radiant floor heating systems are designed to have self-leveling concrete or thinset applied over them. Then the flooring.
Electrical radiant heat mats are also available as area mats and can be covered with a light rug. They will not heat an entire room but add comfort to bathroom floors and reading corners. All electrical mats are available with a thermostat to control the temperature.
Costs of Basement Floor Heating Systems
Basement floor heating has two costs associated with it–operation costs and installation costs.
Operation costs for both hydronic and electrical systems range from $1.00 to $5.00 per square foot for 24 hours of heating. Electrical heating is usually a little more expensive.
Hydronic system installation costs range from $6.00 to $20.00 per square foot of heated floor area. Some of the variables affecting cost include:
- Boiler or hot water tank.
- Installation during house construction or after the floor is in.
- Usually contractor installed.
- Types and quality of control systems.
Electrical system installation costs range from $8.00 to $15.00 per square foot of heated floor area. Some of the variables affecting cost include:
- Type of system – off the shelf or custom-made.
- Installed during construction or after–not in poured concrete.
- DIY or contractor installed.
- Types and quality of control systems.