Underfloor heating principles
The principle of under-floor heating was well-known to both the ancient Romans, and to the Koreans. Today, modern hydronic heating systems are the most efficient form of space heating available
Hydronic floor heating systems use pipes laid in the concrete floor slab to circulate heated water. The heat is then transferred to the surface of the slab, where it provides a comfortable, gentle warmth to the room.
We’ve all experienced the limitations of traditional heating systems. Sometimes you just can’t get warm. Sometimes the front of you bakes while the back of you freezes. The sound of fan-forced systems can be annoying. Fan-forced systems blow dust around the house creating extra work. Many systems produce polluting smoke.
More and more value-conscious Australians are choosing hydronic Under Floor Heating. Why?
- Because there is no fan-forced circulation of air, dust is minimised.
- Individual zones, can be set up to be turned on or off, or set at different temperatures.
- Programmable thermostats start up and shut down the system according to your individual needs.
- High efficiency solar arrays and heat pumps mean that running costs are Vastly reduced.
- Whole-of-life costs put you way in front, with a superior system.
Hydronic (liquid) floor heating are by far the most popular and competitive radiant heating system.
Common hydronic heating systems are based on hot water pumped from a hot water source through tubing underneath the floor; the hot water heats the slab, and the thermal mass of the slab holds the heat and drives it slowly into the house rooms.
Advantages of Hydronic Radiant Heating
Hydronic Radiant Heating offers top comfort, extremely quiet operation, improved air quality (no dust, no eventual toxic or chemical infiltrations…), significant energy savings and is particularly suitable to work with solar water heater systems or high efficiency air source heat pumps.
Most of all, hydronic radiant floor heating means enhanced comfort. The large radiant surface (the whole floor), the nature of the heating (radiation) and the fact that floor surface is itself warm (allowing people to walk around barefoot) explain that enhanced comfort.
The delivery of heat at floor level and the absence of significant airflow provide comfort at relatively low thermostat temperatures (20°C).
Unlike forced-air heating systems, radiant heating doesn’t increase the rate of air infiltration, which is also a source of energy savings.
The so-called “wet” radiant floor installation is based on tubing embedded in a thick concrete slab or in a layer of concrete, gypsum or other material installed on top of a sub-floor.
Concrete slab systems have an excellent heat capacity and can be powered by an evacuated tube solar powered water systems, or high efficiency air source heat pumps.
Radiant floor “dry” installations are relatively new approaches in which the tubing runs in an air space under the floor.
Some installations involve suspending the tubing under the sub-floor between the joists and require reflective insulation under the tubes (in order to direct the heat upward).
Tubing may also be installed between layers of sub-floor, with tubing fitted into aluminum diffusers (to spread the water’s heat across the floor).
Radiant floor design can be rather complex. The length of tubing per square meter of floor depends on many variables: climate, tubing diameter, type of boiler/heat source and controls…
Zoning the radiant floor heating system & controls
The temperature in each room of the house can be controlled by regulating the temperature of the flow of water through each tubing loop – which can be accomplished by valves, pumps and thermostats.
Zoning the system is important, since maintaining different temperatures in different parts of the house allows energy savings and can respond to different needs (spaces with and without solar gains, for instance).