Underfloor Heating

Underfloor heating is a very clean and simple form of heating, ideally suited to today’s well-insulated, low-energy and airtight buildings. An underfloor heating system takes advantage of one of the most basic laws of physics – which is that heat rises. Underfloor heating is the oldest form of central heating, the Romans used a form of underfloor heating called hypocausts, which heated buildings and baths. 

Why would you choose underfloor heating?

Comfort: The most compelling reason to choose underfloor heating is comfort. Radiation, like the heat we get from the sun, is the most natural and comfortable form of heating. Research has shown that people feel more comfortable when they experience warm feet and a cold head. An underfloor heating system produces these conditions naturally, there are no localised hotspots, just a gentle feeling of warmth throughout your home.

Energy-Efficient & Cost-Effective: Because an underfloor heating system uses radiant heat most people find they are comfortable at temperature settings several degrees lower than with other conventional heating systems. You can actually lower your thermostat setting while enjoying the same level of comfort and reducing your heating bills by anything up to 30%. This means that underfloor heating is energy efficient and cost-effective.

underfloor heating

How Underfloor Heating Works

Water (25-40°C) is circulated through a series of polyethylene pipe installed and integrated within the floor make-up. The pipe is then connected to a centrally located manifold. The temperature of each room can be individually controlled as required via room thermostat. Each room thermostat can be set at 2°C lower than a room heated by radiators. This is because underfloor heating delivers 70% radiant heat and 30% convection heat as opposed to radiators, which emit 30% radiant heat and 70% convection heat. This means that an underfloor heating system is a more efficient way of heating your home. Each room can be controlled by a programmable room thermostat allowing each room to have time and temperature control, when any one of these thermostats call for heat they open an electronically operated valve (actuator) that is fitted to the top body of the manifold, this would then turn your pump on and fire up your heat source. Each loop on the manifold is capable of having its own control typically one loop per room.

Radiators distribute heat by convection currents, which can result in draughts and hot spots. Radiators transfer heat into a room largely by convection from a hot metal surface. Because the surface of the radiator is small, in comparison to the volume of the room, it needs a high heat input and doesn’t spread the heat evenly. Convection currents circulate allergens, dust particles, fumes and germs which are then distributed around the building, contributing to an unhealthy atmosphere.

Underfloor Heating is easy to install, requires low maintenance and is very cost effective to run. The room is heated mostly by radiation, like the heat we get from the sun, the most natural and comfortable form of heating. An underfloor heating system creates an even temperature, comfortable environment with no hot or cold draughts, just a gentle feeling of warmth throughout your home. Rooms with high ceilings such as churches, sports halls or industrial units gain even greater benefits. With radiator systems, some of the heat is immediately wasted as it rises to the ceiling. With an underfloor heating system, the heat is concentrated at floor level where it is most needed. In rooms with large areas, underfloor heating is the only way to heat the centre of the floor area effectively.

Underfloor Heating systems goes hand in hand with heat pump installations

An underfloor system heating circulates low temperature water. Most conventional heating systems circulate warm water, usually between 50ºC to 80ºC whereas an underfloor heating system circulates water between 25ºC to 40ºC. A heat pump is most efficient when heating water at lower temperatures, the heat pump efficiency goes up bringing your running cost down.
Underfloor Heating Ballybunion

Main features & benefits

Underfloor Heating also referred to as geothermal heating have become a firm favourite for those undertaking new build projects and the benefits are clear:

Underfloor Heating Controls

Deciding on whether to have underfloor heating installed is one thing, but deciding on the underfloor heating controls and thermostats is another. The control system, like in any heating system, is the key to success. It should be designed to match the application and individual areas should have independent control. Let’s think for a moment how it would be to have a single light switch for the entire house – it really doesn’t make sense does it? However, until recently, a single heating control would have been accepted. Heatmiser is the leading manufacturer of heating control systems. Energywise Ireland stock different types of Heatmiser underfloor heating thermostats from dial and button type to state of the art touch screens. See our heating controls page for more information on this.


According to Part L of the building regulations the recommended U-Value for the floor where under floor heating is being fitted is 0.15W/m2K. This equates to about 150mm of polyiso type insulation board.
Under floor heating is usually installed with a thermostat in each of the main rooms (bedrooms, living rooms etc), but not in the likes of bathrooms and en-suites. Having a thermostat in each room allows for a different temperature to be set in each room. The thermostat control can be just temperature only or they can control the time and temperature for each of the rooms.
The pipes are typically spaced at 150mm (6 inches) apart for most applications. Where there is areas of high heat loss they may be spaced closer together.
The pipes are made from different types of plastic depending on the manufacturer. The best quality pipes are plastic on the outside with a layer of aluminium within that and then lined again on the inside with another plastic layer. The reason for the aluminium layer is to prevent oxygen from diffusing into the heating water which could cause problems with corrosion in the metal parts of the system such as a boiler.
The screed that is used with under floor heating for a ground floor is typically between 75mm and 100mm and is made of a sand and cement mix. It often has polymer fibres mixed in with it for greater strength and to help prevent cracking. Where under floor heating is being installed upstairs a liquid screed is often used and this can be as thin as 35mm.
It is often done to combine under floor heating on the ground floor with radiators on the first floor. This can be done with either a boiler system or a heat pump system.
There is very little chance of a leak occurring in an under floor heating pipe. The only cases (which are very rare) that we have dealt with relating to a leak in an under floor heating pipe is where a trades person drills or cuts down into a floor that has under floor heating pipes in it and this would typically only happen in the construction phase of the house. If this happens the pipe can be repaired with a special type of fitting.


Enquire about Underfloor Heating

Did you know?

Underfloor heating is the oldest form of central heating – the Romans used a form of underfloor heating called hypocausts, which heated buildings and baths.

Radiator V Underfloor


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Energywise Ireland were competitively priced at 15-20% lower than other suppliers offering similar services. They took the time to take us through the new systems being installed and the benefits and cost efficiencies of same. Darren and Berth and the team were extremely professional and knowledgeable. We are blown away by the perfect fresh air and heat balance that the combination of systems has achieved. The house temperature remains at 20 degrees which is a blissful living environment for an Irish winter. Thanks lads for making our self-build easy!
Sonia Towler
Energywise Ireland installed the electrical,led lighting, geothermal heating, HRV and central vacuum in our new home. We found Berth and his team to be very pleasant, focused and committed to their work. Their work was of a very high standard and Berth was always available to discuss any issues that arose during the project and provided invaluable advice. It was a pleasure to have to deal with just one company to cover so many services. I would highly recommend Energywise Ireland.
David Gaynor, Tralee, Co.Kerry