Hydronic Underfloor Heating

Hydronic heating keeps running costs down by allowing a choice of energy sources, since the water can be heated by a range of energy efficient and environmentally friendly heat sources. Gas boilers are typically used, with other options including high efficiency electric heat pumps, geothermal heat pumps and solar energy.

High efficiency condensing boilers are also available and recommended as they have a higher efficiency than gas boilers and have far lower emissions. A condensing boiler recycles the heat that is typically lost in the exhaust of a non-condensing gas boiler. Additionally, much of the exhaust emissions are condensed and discharged into the sewer system. Condensing boilers typically have efficiencies of 95% or more compared with non-condensing gas boilers at around 70-80%.

In Slab Hydronic Under Floor heating

In slab Hydronic floor heating is a storage heating system. The slab is heated by pumping hot water through pipes laid in the concrete slab. This process can take one to two days at the beginning of the winter season, depending on the thickness of the slab and the amount of floor insulation used. Once the slab is heated through, it radiates heat up into the room creating a comfortable environment with no draughts, no dust and no noise.

The pipes used are cross linked polyethylene (PEX) pipes developed in Europe specifically for under floor heating. PEX pipes are extremely tough. They are connected with leak-proof compression sleeve fittings and there is an oxygen barrier applied to the outside of the pipes. We use German made Rehau® pipes that come with a 25 year warranty.

The heating is controlled using floor and air sensing thermostats that adjust the flow rate of hot water through the pipe circuits.

We recommend extruded polystyrene insulation beneath the slab and on exposed slab edges to minimise system heat losses.

In screed Hydronic floor heating is a storage heating system, similar to the in slab system. The screed is heated by pumping hot water through pipes laid in the topping screed. This process can take one to two days at the beginning of the winter season, depending on the thickness of the screed and slab, and the amount of floor insulation used. Once the screed is heated through, it radiates heat up into the room creating a comfortable environment with no draughts, no dust and no noise.

There are two advantages of this system over in slab. The first is that it eliminates possible delays with the concrete pour of slabs, which can often be on the critical path for a building's construction program. The second is that in screed systems can be more responsive with the use of under screed insulation, as this reduces the thermal mass of the system. That means a shorter warm up and cool down period. We recommend 25mm polystyrene insulation beneath the screed.

The pipes used are cross linked polyethylene (PEX) pipes developed in Europe specifically for under floor heating. PEX pipes are extremely tough. They are connected with leak-proof compression sleeve fittings and there is an oxygen barrier applied to the outside of the pipes. We use German made Rehau® pipes that come with a 25 year warranty.

The heating is controlled using floor and air sensing thermostats that adjust the flow rate of hot water through the pipe circuits.

Hydronic heating can be used under battened timber floors. The pipes are laid over insulation panels and sit directly beneath the floor boards. The pipes run in between the battens, which are typically laid at 450mm centres, and pass through small grooves in the battens to cover the entire floor area.

The pipes used are cross linked polyethylene (PEX) pipes developed in Europe specifically for under floor heating. PEX pipes are extremely tough. They are connected with leak-proof compression sleeve fittings and there is an oxygen barrier applied to the outside of the pipes. We use German made Rehau® pipes that come with a 25 year warranty.

The heating is controlled using floor and air sensing thermostats that adjust the flow rate of hot water through the pipe circuits. The thermostats are typically set to a maximum of 27°C to ensure the timber is not over-heated.

We recommend using diffusion plates in addition to 25mm polystyrene insulation beneath the pipes. The diffusion plate system consists of aluminium plates with preformed grooves to take the pipe. The aluminium plates transfer the heat away from the pipes giving a uniform heat distribution beneath the timber floor and enabling a more efficient heat transfer to the timber floor.