Electric vs. Hydronic Radiant Heat Systems The Family Handyman

Electric vs. Hydronic Radiant Heat Systems The Family Handyman

Electric vs. Hydronic Radiant Heat Systems

Heated floors are luxurious and affordable. Well tell you how to select the best floor-warming system for your home.

The benefits of infloor heat

Once you shed your fuzzy slippers and discover the comfort of warm floors, youll be sold. Heated floors, often called radiant floors, offer benefits beyond foot comfort. They keep entry and bathroom floors dry and provide space heating in cold rooms. You can even turn down the thermostat for your central heating system and still keep some rooms warmer.

In this article, well walk you through the types of radiant floor systems you can install in your home. Well tell you the pros and cons, and show you key installation techniques. This will help you decide whether to take on the project yourself or hire a professional. These heating systems are most often installed under ceramic tile in bathrooms, but keep in mind that you can add heat under any type of flooring material (see Floor Coverings and Heated Floors, below). All floor heating systems warm the floor with either electricity or hot water.

Electric systems are simple and affordable

Electric floor systems work just like an electric blanket: Electricity runs through resistance cable and creates heat. Because electricity is fairly expensive, relatively few homes are entirely heated by in-floor electric systems. However, these systems are great for making especially cold floors foot-friendly. They also boost the temperature in an otherwise chilly room by a few degrees. The warm floor in a bathroom makes getting out of the shower a cozier prospect on a cold day. Thats the payoff.

Electric systems have three components: heat cable, a thermostat and a temperature sensor (Figure A below). The thermostat is connected to the homes power supply and turns the heat on and off according to the floors (not the rooms) temperature. A sensor installed in the floor along with the cable tells the thermostat how warm the floor is. (Most people prefer a floor temperature of 80 to 90 degrees F.) The thermostat and sensor are packaged together; cable is usually sold separately. Dont use a thermostat from one manufacturer with cable from another.

The electrical connections require only basic wiring know-how, and laying the floor cable is a DIY-friendly project. Because of this easy installationand the lower cost of materialsan electric system is usually the best choice for small-scale projects like heating a kitchen floor or warming up a cold bathroom. Adding electric heat to a typical bathroom when you install a new floor adds only $200 to $300 to the cost of the project. Operating costs are typically about a half cent per square foot per day.

Often the biggest challenge is fishing electrical cable through finished walls to the thermostat and cable. Since these systems generally draw only 10 to 15 watts per sq. ft. you can usually connect them to an existing circuit to heat a typical bathroom. For a larger room, you may have to run a new cable to the main panel and pay an electrician about $120 to connect the new circuit there.

If youre installing heat over a wood-framed floor, place fiberglass insulation between the joists to drive the heat upward. The system will work fine without insulation but will be more efficient with it. Before you install an electric system over a concrete floor, check the manufacturers instructions they may require a layer of foam insulation over the concrete before the heat cable is installed.

Tip: When you estimate the square footage of a room, include only the areas where you can walk; it makes no sense to heat the floor under appliances or behind the toilet.

Figure A: Electric floor heat details

Electric vs. Hydronic Radiant Heat Systems

Heated floors are luxurious and affordable. Well tell you how to select the best floor-warming system for your home.

The benefits of infloor heat

Once you shed your fuzzy slippers and discover the comfort of warm floors, youll be sold. Heated floors, often called radiant floors, offer benefits beyond foot comfort. They keep entry and bathroom floors dry and provide space heating in cold rooms. You can even turn down the thermostat for your central heating system and still keep some rooms warmer.

Electric vs. Hydronic Radiant Heat Systems The Family Handyman

In this article, well walk you through the types of radiant floor systems you can install in your home. Well tell you the pros and cons, and show you key installation techniques. This will help you decide whether to take on the project yourself or hire a professional. These heating systems are most often installed under ceramic tile in bathrooms, but keep in mind that you can add heat under any type of flooring material (see Floor Coverings and Heated Floors, below). All floor heating systems warm the floor with either electricity or hot water.

Electric systems are simple and affordable

Electric floor systems work just like an electric blanket: Electricity runs through resistance cable and creates heat. Because electricity is fairly expensive, relatively few homes are entirely heated by in-floor electric systems. However, these systems are great for making especially cold floors foot-friendly. They also boost the temperature in an otherwise chilly room by a few degrees. The warm floor in a bathroom makes getting out of the shower a cozier prospect on a cold day. Thats the payoff.

Electric systems have three components: heat cable, a thermostat and a temperature sensor (Figure A below). The thermostat is connected to the homes power supply and turns the heat on and off according to the floors (not the rooms) temperature. A sensor installed in the floor along with the cable tells the thermostat how warm the floor is. (Most people prefer a floor temperature of 80 to 90 degrees F.) The thermostat and sensor are packaged together; cable is usually sold separately. Dont use a thermostat from one manufacturer with cable from another.

The electrical connections require only basic wiring know-how, and laying the floor cable is a DIY-friendly project. Because of this easy installationand the lower cost of materialsan electric system is usually the best choice for small-scale projects like heating a kitchen floor or warming up a cold bathroom. Adding electric heat to a typical bathroom when you install a new floor adds only $200 to $300 to the cost of the project. Operating costs are typically about a half cent per square foot per day.

Often the biggest challenge is fishing electrical cable through finished walls to the thermostat and cable. Since these systems generally draw only 10 to 15 watts per sq. ft. you can usually connect them to an existing circuit to heat a typical bathroom. For a larger room, you may have to run a new cable to the main panel and pay an electrician about $120 to connect the new circuit there.

If youre installing heat over a wood-framed floor, place fiberglass insulation between the joists to drive the heat upward. The system will work fine without insulation but will be more efficient with it. Before you install an electric system over a concrete floor, check the manufacturers instructions they may require a layer of foam insulation over the concrete before the heat cable is installed.

Tip: When you estimate the square footage of a room, include only the areas where you can walk; it makes no sense to heat the floor under appliances or behind the toilet.

Figure A: Electric floor heat details


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