Radiant floor heating is a heating system that is gaining popularity among homeowners due to its numerous benefits.

It provides a comfortable and consistent warmth throughout the home, without the need for bulky radiators or ductwork.

In this article, we will discuss how radiant floor heating works, the different types of systems available, installation procedures, and maintenance tips.

Radiant floor heating being installed

The History of Radiant floor heating

Radiant floor heating has been used for centuries, with the first known system dating back to ancient Korea, where hot air was circulated under a floor using flues.

However, the modern concept of radiant floor heating can be traced back to the Roman Empire, where underfloor heating was used in public baths and private villas.

During the Middle Ages, radiant floor heating fell out of favor, and it was not until the 1930s that it began to gain popularity again in Europe.

The first modern radiant floor heating system was installed in a church in Switzerland in 1937, and by the 1950s, radiant floor heating had become a popular heating solution in Europe.

In the United States, radiant floor heating did not become popular until the 1980s, when advancements in technology made it a more practical and efficient heating solution for homes and businesses.

How Radiant Floor Heating Works

Radiant heating is a heating method that relies on the transfer of heat through electromagnetic waves, without the need for a physical medium. In radiant floor heating, heat is transferred from the floor to the surrounding objects and air through infrared radiation.

In radiant floor heating, a heating element is installed beneath the flooring surface, either through electric cables or hydronic piping. When the heating element is turned on, it radiates heat through infrared radiation, which warms up the objects and air in the room.

Unlike forced-air heating systems, which heat the air and then distribute it through ductwork, radiant floor heating provides a more comfortable and consistent warmth throughout the room. The heat is evenly distributed, without any cold spots or drafts, which makes it a popular choice for those who suffer from allergies or respiratory issues.

Heat Transfer Mechanisms

There are three main heat transfer mechanisms involved in radiant floor heating: conduction, convection, and radiation.

Conduction involves the transfer of heat through physical contact. In radiant floor heating, heat is conducted from the heating element to the flooring material, and then to the air and objects in the room.

Convection involves the transfer of heat through the movement of air. In radiant floor heating, the warm air rises from the heated flooring surface, creating a natural convection current that circulates the warm air throughout the room.

Radiation involves the transfer of heat through electromagnetic waves. In radiant floor heating, the heating element radiates heat through infrared radiation, which is absorbed by the surrounding objects and air in the room.

Types of Radiant Floor Heating Systems

There are several types of radiant floor heating systems, each with its own unique benefits and installation requirements.

#1 Hydronic Radiant Floor Heating Systems

Hydronic radiant floor heating systems use hot water or a mixture of water and antifreeze as the heat transfer medium. A boiler heats the water and pumps it through a series of pipes installed beneath the flooring surface, which then radiates heat into the room. This type of system is more commonly used for larger areas, and it can be connected to a variety of heat sources including geothermal, solar, and traditional boilers.

#2 Electric Radiant Floor Heating Systems

Electric radiant floor heating systems use electric cables or mats as the heating element. The cables or mats are installed beneath the flooring surface and are connected to a thermostat, which regulates the temperature of the floor. This type of system is a popular choice for small areas such as bathrooms or kitchens.

#3 Air-Heated Radiant Floors

Air-Heated Radiant Floors use a system of ductwork installed beneath the flooring surface to distribute heated air throughout the room. This type of system is less common than hydronic or electric systems and can be less efficient due to heat loss through ductwork.

#4 Outdoor Radiant Heating

Outdoor Radiant Heating systems can be used to melt snow and ice on walkways, driveways, and other outdoor surfaces. These systems typically use a combination of hydronic and electric systems to heat the surface and prevent ice buildup.

#5 Solar Radiant Floors

Solar Radiant Floors use solar energy to provide heat. Solar panels installed on the roof or in a nearby location collect sunlight, which is then used to heat a fluid that circulates through pipes installed beneath the flooring surface. This type of system is a renewable energy solution that can reduce energy costs and environmental impact.

Benefits of Radiant Floor Heating

Radiant floor heating offers numerous benefits over traditional heating systems, making it an attractive choice for homeowners seeking an efficient and comfortable heating solution.

A. Invisible Heating System

Radiant floor heating is installed beneath the flooring surface, making it an invisible heating system that does not take up valuable wall or floor space. This allows for more design freedom and eliminates the need for bulky radiators or ductwork.

B. Energy Efficiency and Cost Effectiveness

Radiant floor heating is more energy-efficient than traditional heating systems, as it does not rely on forced air to distribute heat. This can result in lower energy bills and cost savings over time.

C. Smart Thermostat Compatibility

Radiant floor heating is compatible with smart thermostats, allowing for easy temperature control and automation. This can further increase energy efficiency and cost savings.

D. Fewer Design Limitations

Radiant floor heating allows for more design freedom, as it does not have the same limitations as traditional heating systems. This can result in more creative and personalized interior design options.

E. Low Maintenance

Radiant floor heating requires minimal maintenance, as there are no moving parts or filters to clean. This can result in fewer repair costs and a longer lifespan for the heating system.

F. Compatible with All Flooring Types

Radiant floor heating is compatible with all types of flooring, including tile, hardwood, and carpet. This allows for more flexibility in flooring options and design choices.

A radiant floor heating system being installed in backyard.

G. Easy Installation

Radiant floor heating can be easily installed in both new and existing homes. While the installation process may vary depending on the type of system chosen, it generally requires minimal disruption to the home.

H. Improved Air Quality

Radiant floor heating does not rely on forced air to distribute heat, which can lead to improved air quality as there is less dust and allergens circulating in the air.

Disadvantages of Under-Floor Heating

While radiant floor heating offers numerous benefits, there are also some potential disadvantages to consider.

Replacing Old Flooring

Installing radiant floor heating often requires the removal of the existing flooring, which can be a costly and time-consuming process. This may not be feasible for homeowners who want to keep their current flooring or for those with limited time and budget for renovation.

Installation Time

Installing radiant floor heating can be a time-consuming process, especially for larger areas or for hydronic systems that require a network of pipes to be installed. This may not be ideal for homeowners who want a quick and easy heating solution.

Floor Height Issues

Installing radiant floor heating can add height to the flooring surface, which may cause issues with doors, trim, and other architectural elements. This may require additional renovations or adjustments to accommodate the increased floor height.

Incompatibility with Some Flooring Types

While radiant floor heating is generally compatible with all types of flooring, there are some materials that may not be suitable, such as certain types of vinyl or laminate. Homeowners should consult with their flooring and heating contractors to ensure that the chosen flooring material is compatible with the radiant floor heating system.

Difficulty in Locating Leaks or Damages

In hydronic radiant floor heating systems, locating leaks or damages in the piping can be difficult and require extensive troubleshooting. This may result in increased repair costs and disruption to the home.

Uneven Heating in Multi-Story Homes

radiant floor heating may not provide even heating in multi-story homes, as heat may rise to the upper levels and leave the lower levels cooler. Additional heating solutions may be necessary to ensure consistent warmth throughout the home.

While these potential disadvantages should be considered when choosing a heating solution, they do not necessarily outweigh the benefits of radiant floor heating. Homeowners should carefully weigh the pros and cons of radiant floor heating and consult with their heating and flooring contractors to determine the best radiant heating solution for their home.

Best Areas to Install Radiant Heating

AreaBenefits
BathroomsComfortable and warm surface to step on after a shower or bath
KitchensProvides a comfortable workspace and eliminates the need for bulky radiators or space heaters
BedroomsOffers a comfortable sleeping environment and eliminates the need for additional heating
GaragesProvides efficient heating for workspaces or storage areas
Home OfficesOffers a comfortable and productive work environment
BasementsHelps to eliminate dampness and provides consistent warmth
Sun RoomsOffers a comfortable space to enjoy the outdoors year-round
DrivewaysMelts snow and ice, providing safe and easy access to the home
Tiny Homes and Mobile HomesProvides an efficient heating solution in small spaces
Tree HousesOffers a unique and cozy heating solution for outdoor spaces

Comparing Radiant Heating With Other Systems

When it comes to choosing a heating system for your home, there are several options to consider. Here, we will compare electric radiant heating to other heating alternatives:

Furnaces and Forced Air

Furnaces and forced air systems are a popular choice for heating homes, as they can provide quick and powerful heat. However, they can also be noisy and result in uneven heating, as warm air rises to the upper levels of a home and leaves lower levels cooler. They also require regular filter changes and maintenance to ensure efficiency, and can be costly to repair or replace.

Boilers and Water-Based Systems

Boilers and water-based heating systems use hot water or steam to heat a home. These systems are often used in conjunction with radiators or baseboards to distribute heat. While they can provide even heating throughout a home, they can be expensive to install and maintain. They also require regular maintenance to prevent leaks and ensure efficiency, and can be costly to repair or replace.

Electric Baseboards

Electric baseboards use electric heating elements to warm a room, making them a cost-effective heating solution for smaller spaces. However, they can be expensive to run for larger areas and can be unsightly, taking up valuable wall space. They also do not provide even heating throughout a room, as heat tends to rise towards the ceiling.

Hybrid Heating

Hybrid heating systems combine two or more types of heating systems, such as a furnace and a heat pump. These systems can be more energy-efficient than single-system options, but can be costly to install and maintain. They also require regular maintenance and can be complex to operate.

Space Heaters

Space heaters are a portable and affordable option for heating small areas, such as bedrooms or offices. However, they can be a safety hazard if not used properly and can be expensive to run over the long term. They also do not provide even heating throughout a room and can be unsightly, taking up valuable floor space.

Performance

When it comes to the performance of radiant floor heating, there are several factors to consider. Here, we will discuss insulation recommendations and the performance of radiant floor heating in different climates:

Insulation Recommendations

Proper insulation is crucial for the performance of radiant floor heating.

Without adequate insulation, heat may escape through the flooring and subfloor, resulting in higher energy bills and decreased efficiency.

The insulation requirements for radiant floor heating will vary depending on the type of system and the climate in which it is installed. In general, it is recommended that a minimum of R-11 insulation be used for hydronic systems, while electric systems may require up to R-19 insulation.

Performance in Different Climates

Radiant floor heating can provide efficient and comfortable heating in a variety of climates. However, the performance of the system may be affected by the climate in which it is installed.

In colder climates, radiant floor heating may need to work harder to maintain a consistent temperature, which can result in higher energy bills. In warmer climates, radiant floor heating may not be as necessary, as natural heat from the sun and other sources may provide sufficient warmth.

However, radiant floor heating can still be a valuable addition to homes in warmer climates, as it provides even heating and eliminates the need for bulky radiators or ductwork.

How to Install Radiant Floor Heating?

Installing radiant floor heating can provide efficient and comfortable heating for your home. Here, we will discuss how to install radiant floor heating, including electric and hydronic systems, as well as tips and considerations for specific installation scenarios:

Electric Heated Floor Systems

Electric heated floor systems are a popular choice for radiant floor heating, as they are easy to install and require minimal maintenance. To install an electric system, a heating mat or cable is installed on top of the subfloor, and then covered with a layer of thinset mortar and tile or other flooring material.

Hydronic Heated Floor Systems

Hydronic heated floor systems use hot water or a mixture of water and antifreeze to heat the flooring. To install a hydronic system, pipes are installed in the subfloor or on top of it, and then connected to a boiler or hot water heater.

Electric System Installation Tips

When installing an electric system, there are several tips to keep in mind to ensure a successful installation. These tips include properly measuring the floor space, using the correct size heating mat or cable, properly spacing the heating elements, using a compatible thermostat, and following manufacturer instructions carefully.

Tile Installation Same Day

In some cases, it is possible to install tile or other flooring material on top of a newly installed radiant floor heating system on the same day. This can save time and simplify the installation process, but it is important to follow manufacturer instructions carefully to ensure a proper installation.

Radiant Heat Subfloor

Installing radiant heat directly into the subfloor can provide efficient and consistent heating throughout a room. However, this installation method can be more difficult and time-consuming than other options, and may require additional insulation to prevent heat loss.

Radiant Heating in Concrete

Radiant heating can also be installed in concrete floors, providing efficient and even heating throughout the home. This method may require additional time and effort during installation, but can provide long-term benefits in terms of energy efficiency and comfort.

In-Joist Radiant Floor Heating

In-joist radiant floor heating involves installing heating elements in the joist bays beneath the subfloor. This method can be a good option for retrofitting an existing home, but may require access to the subfloor from below.

Floating Floor Over Radiant Heat

A floating floor can be installed over radiant heat, providing an efficient and comfortable heating solution. This installation method involves using a special underlayment to insulate the flooring from the heating elements.

Retrofit Radiant Floor Heating

Retrofitting an existing home with radiant floor heating can be a cost-effective and energy-efficient solution. However, it is important to consider the existing flooring and subfloor when planning the installation, as retrofitting may require additional insulation or modifications to the existing structure.

Installing Heated Floors Under Tile

Installing radiant floor heating under tile can provide a comfortable and efficient heating solution in bathrooms, kitchens, and other tiled areas. This installation method involves installing a heating mat or cable directly beneath the tile, and can be done using a variety of materials and techniques.

Things To Consider Before Buying a Radiant Floor Heating System

When shopping for a radiant floor heating system, there are several factors to consider. Here, we will discuss the most important considerations when selecting a radiant floor heating system:

Room Size: The size of the room you wish to heat is an important consideration when selecting a radiant floor heating system. Larger rooms may require more heating elements or a more powerful heating system to maintain a consistent temperature. It is important to carefully measure the room and consult with a professional installer to ensure that the heating system you select is the right size for your needs.

Heat Controllers: Heat controllers are an essential component of a radiant floor heating system, allowing you to adjust the temperature of the flooring as needed. There are several types of heat controllers available, including basic manual thermostats and more advanced digital thermostats that can be controlled remotely using a smartphone or other device. When selecting a heat controller, it is important to consider your specific needs and preferences, as well as the compatibility of the controller with your heating system.

Warranty: The warranty provided by the manufacturer of your radiant floor heating system is an important consideration, as it can provide protection and peace of mind in case of any issues or malfunctions with the system. When selecting a radiant floor heating system, be sure to carefully review the warranty terms and conditions, including the length of the warranty, any exclusions or limitations, and the process for filing a claim in case of any issues.

Cost of Radiant Floor Heating

Here, we will discuss the cost of radiant floor heating, including a cost comparison to other heating alternatives and the factors that can affect the overall cost of installation:

Cost Comparison to Other Heating Alternatives –  When considering the cost of radiant floor heating, it is important to compare it to other heating alternatives. While radiant floor heating may have a higher upfront cost, it can provide long-term energy savings and improved comfort compared to other heating options. For example, compared to a forced-air heating system, radiant floor heating can be up to 30% more efficient and can provide a more consistent and comfortable heating experience.

Factors that Affect Cost – The overall cost of installing a radiant floor heating system can vary based on several factors. These factors may include the size of the room or area being heated, the type of heating system being installed, and the cost of labor and materials in your area. Other factors that can affect the cost may include the complexity of the installation, the type of flooring being installed, and any additional modifications or insulation that may be required.

To get an accurate estimate of the cost of installing a radiant floor heating system, it is important to consult with a professional installer and obtain multiple quotes. This can help you compare the cost and features of different systems and ensure that you select a system that meets your needs and budget.

Radiant Heating in Commercial Buildings

Radiant heating is not only suitable for residential buildings but also has applications in commercial buildings. Here, we will discuss the advantages and disadvantages of radiant heating in commercial buildings and its potential applications:

Advantages and Disadvantages

Radiant heating can provide several advantages for commercial buildings, including improved comfort, energy efficiency, and space-saving design. Radiant heating can also provide a more uniform heating experience compared to traditional forced-air heating systems. However, there are also some potential disadvantages, such as higher upfront costs and the need for professional installation and maintenance.

Application of Radiant Heating in Commercial Buildings

Radiant heating can be applied in various commercial building types, including offices, retail spaces, and industrial buildings. In offices and retail spaces, radiant heating can provide a comfortable and efficient heating solution without taking up valuable floor space. In industrial buildings, radiant heating can be used for process heating or to provide a comfortable working environment for employees.

Some common applications of radiant heating in commercial buildings include using underfloor heating systems or radiant panels mounted on walls or ceilings. The type of system used will depend on the specific needs and characteristics of the building, as well as the desired heating performance and efficiency.

Choosing Hydronic Radiant Floor Heating Pipes

One of the critical aspects of designing a radiant floor heating system is selecting the right pipes. Here are some factors to consider when choosing radiant floor heating pipes.

Material

Radiant floor heating pipes come in various materials. The most common ones are cross-linked polyethylene (PEX), PEX-Al-PEX, polybutylene (PB), and copper. Each material has its unique properties, advantages, and disadvantages.

PEX is the most popular material for radiant floor heating pipes. It is affordable, durable, and easy to install. PEX pipes come in different colors to identify the hot and cold water lines. However, PEX is susceptible to damage from sunlight exposure and may leach chemicals into the water supply.

PEX-Al-PEX is an upgraded version of PEX pipes with a layer of aluminum in between the PEX layers. This design makes it more durable and better at retaining heat. However, it is more expensive than PEX pipes.

Polybutylene (PB) pipes are cheaper than PEX pipes, but they are not as durable. PB pipes are prone to cracking, which may cause water damage. Additionally, PB pipes may deteriorate when exposed to chemicals in the water supply.

Copper pipes are the most durable but are also the most expensive. They are less prone to damage and can handle high water temperatures. However, copper pipes are challenging to install and may require specialized tools.

Pipe Diameter

The diameter of the radiant floor heating pipes plays a crucial role in the efficiency of the system. The larger the diameter of the pipes, the more water the system can circulate, which translates to higher heat output. The diameter of the pipes also affects the system’s response time and the amount of heat stored in the flooring.

The factors influencing the pipe diameter choice include the type of flooring, the insulation, and the heating load of the building. It is essential to consult with a professional to determine the optimal pipe diameter for your specific application.

Pipe Spacing

The spacing of the radiant floor heating pipes is another crucial factor to consider. The optimal spacing ensures even heat distribution across the flooring, eliminating cold spots.

The ideal pipe spacing depends on several factors, including the heating load, the water temperature, and the floor covering. The standard pipe spacing ranges from 6 to 12 inches apart, but the spacing may be closer together in areas that require more heating, such as bathrooms or entryways.

News About Radiant Heating

28-Mar-2023 Radiant heating and cooling systems market to grow at a CAGR of 7.32% from 2021 to 2026: Use of PEX tubing will drive market growth – Technavio