When using a radiator system the heat output is a function of the surface area of the radiator and the mean water temperature flowing through the circuit.
The principal is the same for floor heating, but as the floor area is considerably greater than that of a radiator the mean water temperature can be reduced well below that of a radiator circuit.
The heat output from the floor is a function of the following factors:
• Mean water temperature
• Spacing between the pipes
• Floor structure
• Floor finish
A Begetube floor heating system consists of circuits of pipe embedded in the floor; each of these circuits is connected to a distribution manifold onto individual pairs of valves. Room thermostats and actuators can then easily control the separate circuits.
The Begetube floor-heating pipe is cross-linked polyethylene with an EVOH oxygen barrier built into the pipe wall. Pex is an incredibly durable material and accounts for about 60% of all UK floor heating installations. Actual life of this material is unknown but mechanical testing at elevated pressures and temperatures have indicated an absolute minimum life of fifty years with a safety factor of 2.5.
Control of the water temperature is important; water at boiler temperature should not be allowed to enter the floor structure. This control is achieved by either a manually operated three port blending valve with a remote sensing control head, or by using a weather compensating control system.
The source of heated water is generally a standard boiler, either oil or gas. It is possible to use alternatives such as ground source heat pumps or solar devices, however care should be taken to ensure that the control systems match the requirements of the floor heating.
A more detailed technical breakdown of all aspects of floor heating is provided in the following pages.
