Electric vs Wet Underfloor Heating

Before deciding, consider the differences between electric and wet underfooor heating.

It is not a new concept by any means, underfloor heating has existed in various guises throughout history, most notably when the Romans implemented their own system of heating walls and floors with a furnace.

However, today’s underfloor heating has developed rapidly since the failed and expensive products seen in this country in the 1960’s, and both wet and dry systems have become much more advanced.

It is essential to look at the merits of both types individually and to consider which suits the application best. The best system to be fitted into a new build house may vary greatly from the best type of heating for a renovation project, or a commercial building.

Electric underfloor heating

Electric underfloor heating involves the laying of high resistance cable or matting which heats the flooring directly; the heat is then radiated into the room. It is one of the most versatile types of heating system as it can be integrated into the design of a new property, or retrofitted without the expense of other heating systems.

The cable or matting can be cut to size to suit the shape of any room, making electric systems much more suitable for small and awkward shaped rooms. More sophisticated systems allow you to fit different rated cables in different rooms.

This gives full control over the heating and each room can have its own thermostat, rather than a single control that you would associate with traditional central heating.

It is considerably cheaper to fit than wet systems, particularly when refurbishing a property, as it doesn’t involve digging up floors or plumbing alterations.

It can actually be fitted quite easily by any DIY enthusiast; the only expertise required is that of a qualified electrician to connect to the mains supply.

There are very few restrictions on the type of floor it can be fitted to, and it is suitable with most materials. Some engineered laminate flooring does not have a great tolerance to temperature, so it may be necessary to source a ribbon cable system, which is capable of operating at lower temperatures around 30°C.

Wet underfloor heating

Water based underfloor heating is similar in principle to the electric

system, but utilises a network of pipes under the floor. Warm water, typically from a gas boiler, is circulated through the pipes to enable the heating of the flooring.

Although it is generally more expensive to install than electric systems, its running costs are cheaper, so it may be a more economical decision in the long term.

Is underfloor heating right for your property, and which type to buy Electric or a Wet system?

Wet systems are best suited to new buildings as the pipe work can be incorporated into the initial design and the system installed during construction.

Retrofitting is possible, but it is much more difficult and expensive. It would usually involve digging up the floor to lay pipes, and connection to the boiler and the plumbing alterations that go with it.

The cost of retrofitting makes wet systems undesirable for refurbishments, as it would take many years for savings on energy bills, to offset that initial outlay.

Underfloor systems very rarely have problems with leakage or failed valves, but any repairs to a wet system could be costly, as it is difficult to get to the piping to work on it.

Specification and installation

Both systems offer advantages over central heating; they are more energy efficient and provide a much better distribution of heat. Radiators tend to create excess heat in high areas near the ceiling, while leaving the floor cold.

Underfloor heating provides an even release of heat throughout the surface of the floor and maintains the right temperature from floor to ceiling.

But which is best for your specific property? Eectric systems are very well suited to renovation projects, as they can be fitted so cheaply. The profile of most systems is no more than 3mm, so the flooring would not need to be raised significantly.

This s often something that people overlook; if the floor is raised too much, it can mean expensive alterations to skirting and to doors within the property.

If the building already has a low ceiling, then raising the floor could exaggerate the problem. As electric cable and matting can be cut to suit, it will fit into any room no matter how small, and no matter what shape.

Electric systems are also one of the best types of heating available for buildings with no mains gas supply.

Wet systems are much better suited to new buildings as they can be part of the design process from the outset. The pipe work can be laid and the system fitted at ‘first fix’, which reduces the amount of time on site and the cost of installation.

The extra work required to retrofit a wet system is unlikely to be cost-effective when all things are taken into account.

Wet systems are specified much more often on new build projects because they are cheaper to run than electric underfloor heating, and are therefore more energy efficient over the long term.

There are some property types where underfloor heating may not be the best option at all. Underfloor systems may struggle to fully heat buildings with poor insulation, or witrh very large rooms.

If you are fitting underfloor heating in a conservatory, you may find that underfloor heating has a very slow heat up time, if the room has previously been allowed to get cold; bear in mind that you may need to have the heating on a timer  to ensure the conservatory is heated before you go in.

The Benefits of both

Both systems have advantages over conventional heating systems. They can provide warmth and comfort to stone or tiled floors, and are completely concealed under the floor.

They are silent systems and don’t make all the little noises we associate with radiators. When replacing radiators, they free up all of the wall space in the room, allowing a complete redesign if desired.

The costs

The cost of laying a system is around £18 per square metre for a wet system and £15 per square metre for an electric heating system; the difference of £3 can amount to a reasonable sum of money if it is a large property.

The cost of the connections to the plumbing and/or electric is approximately £180 per zone for an electric system, and £240 for a water based installation.

Running costs depend on the cost of gas and electricity, the efficiency of the boiler or heat source if a wet system is used, and how well the property is insulated.

Electricity is around 10-12p per KWh while gas is around the 4-6p per KWh mark; so a wet system could be up to three times more economical than a dry system.

Summary

Underfloor heating is a viable choice of heating system if you are building or renovating a house, but it is important to assess the suitability of wet and dry systems before making a decision.

Calculating the potential heat generation and the existing heat loss in a property will give some idea as to how effective underfloor heating might be.