Radiant heating occurs when a hot surface heats other objects around it. Radiant heating has a long history of use in Roman and Korean buildings, and is much more efficient than standard ways of heating the air in a building. Underfloor radiant heating is the most common type of radiant heating used in buildings, but wall and ceiling radiant heating systems are also used. Radiant heating can also be used to heat outdoor areas.
History of radiant heating
The Romans were the first to use radiant floor heating systems. These systems were based on hypocausts and used hot air for heating. The floor was placed on top of many piles of bricks, leaving room for hot air and steam produced by a kiln to pass under the floor. The hot air rose through chimneys on the sides of the walls, so the hot air and steam never reached the living rooms. These systems were very expensive to build and maintain, so only the wealthy could afford them.
In Korea, radiant floor heating has been used for about 2,000 years. Ondol, meaning "hot stone," involves the use of stones and underground ducts to help transport hot air from the kitchen to the rooms of the house. Most houses and buildings in Korea still use ondol, although they now use hot water and electrical systems. American architect Frank Lloyd Wright discovered ondol at the turn of the century and used it in many of his building designs. Wright also invented underfloor hot water systems.[1].
Types of radiant heating
Underfloor heating
The most common type of radiant heating is underfloor heating. There are three types of underfloor heating: hot air systems, hot water systems and electric systems.
Hot air systems use hot air to heat the ground, similar to the Roman systems. However, air does not hold heat very well, and these systems are not recommended for residential use. [2].
Hot water systems are the most popular and cost-effective for cold climates. In this type of system, water is heated by a boiler and pumped through pipes placed beneath the ground. Hot water systems can also be combined with solar thermal energy to make them more environmentally friendly. Solar thermal energy uses sunlight to heat water, which can then be used in the underfloor heating system.
Wet underfloor heating system
Introduction
Radiant heating occurs when a hot surface heats other objects around it. Radiant heating has a long history of use in Roman and Korean buildings, and is much more efficient than standard ways of heating the air in a building. Underfloor radiant heating is the most common type of radiant heating used in buildings, but wall and ceiling radiant heating systems are also used. Radiant heating can also be used to heat outdoor areas.
History of radiant heating
The Romans were the first to use radiant floor heating systems. These systems were based on hypocausts and used hot air for heating. The floor was placed on top of many piles of bricks, leaving room for hot air and steam produced by a kiln to pass under the floor. The hot air rose through chimneys on the sides of the walls, so the hot air and steam never reached the living rooms. These systems were very expensive to build and maintain, so only the wealthy could afford them.
In Korea, radiant floor heating has been used for about 2,000 years. Ondol, meaning "hot stone," involves the use of stones and underground ducts to help transport hot air from the kitchen to the rooms of the house. Most houses and buildings in Korea still use ondol, although they now use hot water and electrical systems. American architect Frank Lloyd Wright discovered ondol at the turn of the century and used it in many of his building designs. Wright also invented underfloor hot water systems.[1].
Types of radiant heating
Underfloor heating
The most common type of radiant heating is underfloor heating. There are three types of underfloor heating: hot air systems, hot water systems and electric systems.
Hot air systems use hot air to heat the ground, similar to the Roman systems. However, air does not hold heat very well, and these systems are not recommended for residential use. [2].
Hot water systems can also work in reverse by running cold water through pipes to cool the building. However, this technology is difficult to use properly and can result in condensation on the floor, which can ruin hardwood or carpet floors and make people more likely to fall.
Electrical systems are made of electrical cables that are placed under the floor. Electricity is then used to heat the wires, and this type of system can be turned on or off much faster than a hot water system. However, these systems are often more expensive than hot water systems due to high electricity prices, especially if the hot water system includes the use of solar thermal energy. The high cost of an electric heating system can be reduced if the floor can be heated during non-peak hours, such as late at night, and left off during the day. Electrical systems are also less environmentally friendly because electricity is typically produced by burning fossil fuels, which increases carbon emissions.
Underfloor heating systems can be installed both dry and wet. Wet systems are placed and then concrete is poured over them. Concrete floors retain heat very well, but can take a long time to absorb it. Dry systems work in open air spaces between the foundation and the ground, but can be less efficient because they also have to heat the air. However, dry systems are much easier to reach if the system breaks or leaks.
Any type of underfloor heating can be used, but ceramic tiles are the most popular flooring material because they transfer and store heat well. Materials such as wood, carpet, or linoleum tile decrease heat transfer from the underfloor system and the system should be set at a higher temperature if any of these materials are used.
Wall and ceiling heating
Wall and ceiling radiant heating systems are typically made of aluminum panels hung on the walls or ceiling. Like underfloor heating, these panels can be heated with hot water or electricity. However, hot water heated panels often leak, so electric panels are the most common. These panels cannot heat as much surface area as a radiant floor system, but they can be turned on and off quickly when a person enters or leaves the room. Electrical panels can reduce energy costs if the panels are left turned off in empty rooms.[3].
Outdoor heating
Using outdoor radiant heating is much more practical than heating air because the air is always moving outside. Outdoor radiant heaters are almost always electrical devices and usually portable, although it is possible to install radiant underfloor heating under a patio.
Hot water systems are the most popular and cost-effective for cold climates. In this type of system, water is heated by a boiler and pumped through pipes placed beneath the ground. Hot water systems can also be combined with solar thermal energy to make them more environmentally friendly. Solar thermal energy uses sunlight to heat water, which can then be used in the underfloor heating system.
Hot water systems can also work in reverse by running cold water through pipes to cool the building. However, this technology is difficult to use properly and can result in condensation on the floor, which can ruin hardwood or carpet floors and make people more likely to fall.
Electrical systems are made of electrical cables that are placed under the floor. Electricity is then used to heat the wires, and this type of system can be turned on or off much faster than a hot water system. However, these systems are often more expensive than hot water systems due to high electricity prices, especially if the hot water system includes the use of solar thermal energy. The high cost of an electric heating system can be reduced if the floor can be heated during non-peak hours, such as late at night, and left off during the day. Electrical systems are also less environmentally friendly because electricity is typically produced by burning fossil fuels, which increases carbon emissions.
Underfloor heating systems can be installed both dry and wet. Wet systems are placed and then concrete is poured over them. Concrete floors retain heat very well, but can take a long time to absorb it. Dry systems work in open air spaces between the foundation and the ground, but can be less efficient because they also have to heat the air. However, dry systems are much easier to reach if the system breaks or leaks.
Any type of underfloor heating can be used, but ceramic tiles are the most popular flooring material because they transfer and store heat well. Materials such as wood, carpet, or linoleum tile decrease heat transfer from the underfloor system and the system should be set at a higher temperature if any of these materials are used.
Wall and ceiling heating
Wall and ceiling radiant heating systems are typically made of aluminum panels hung on the walls or ceiling. Like underfloor heating, these panels can be heated with hot water or electricity. However, hot water heated panels often leak, so electric panels are the most common. These panels cannot heat as much surface area as a radiant floor system, but they can be turned on and off quickly when a person enters or leaves the room. Electrical panels can reduce energy costs if the panels are left turned off in empty rooms.[3].
Outdoor heating
Using outdoor radiant heating is much more practical than heating air because the air is always moving outside. Outdoor radiant heaters are almost always electrical devices and usually portable, although it is possible to install radiant underfloor heating under a patio.