Ever wondered what a wet or water underfloor heating system would bring to your property over and above radiator heating? If so, this guide is for you. We look at every aspect of how underfloor heating works, the efficiencies and comfort that it brings, measuring it against a radiator heating system.
What is Underfloor Heating?
Underfloor heating is, as the name suggests, a means of heating a home, business premises, single or multiple rooms, warehouses etc. by heat radiating through the floor.
It is not a new system, with today’s wet underfloor heating systems being modern versions of the system used by Romans and ancient Greeks. Hypocaust, or ‘fire under the floor’, was a clean, safe and relatively easy way of heating the room above.
A wet underfloor heating system uses similar principles to that of water circulating through a radiator system in a property: hot water circulates through plastic piping laid in the subfloor (the section beneath the top layer of floor surface). The heat from the water radiates through the flooring material, making for a warm surface beneath your feet.
The Boiler
Like a radiator system, the efficiency of the system lays in how you use it but also in the efficiency of the boiler pumping the hot water through the system. The more modern and efficient this boiler, the cheaper the heating system will be to run.
There are many kinds of boilers; currently, the most efficient with a rating of 90% or more is a condensing combi boiler. They use heat in the exhaust flue gas to preheat cold water going into the boiler, and this means a higher level of efficiency for any heating system, but especially with a wet underfloor heating system.
Lower Temperature
Efficient and effective, the underfloor heating system runs at a lower temperature for longer. This means that you save money on your heating bill, as you use less energy to heat your property. Typically, floor thermostats are set at 21°C but you can, of course, set it to suit you. Underfloor heating has a lower maximum running a temperature than radiators, and there are pros to this: as well as lower heating bills, and the heat in your home is at a much more comfortable level.
Efficient
You can save even more money by controlling your underfloor heating system. The idea behind any heating system is that you have control over it, hour-by-hour if necessary. With a responsive thermostat, preferably a smart thermostat, you can control the temperature in your home to within half a degree. With a multi-zone underfloor heating system, you can control the heat in different areas of your home, or even room by room if that is the system you opt for.
For example, you may want more heat in the bathroom for the evening or first thing in the morning but want a lower temperature in the bedroom during the day and so on. Thinking of your heating system in zones means you control the heat far more efficiently and that means two things: a home that is comfortable and warm but without a massive heating bill!
But what else do you need to know about underfloor heating?
The Pros
There are many advantages and benefits to investing in a wet underfloor heating, no matter how large or small your property. It is a versatile heating system and one that will provide a comfortable level of heat.
#1 Out of Sight
A central heating system, complete with boiler and radiators, is the usual form of heating system in the home. From the 1930s onwards, it became the accepted norm of keeping a home warm – clean and safe; it provided a high level of heat across the home, something that was very welcome in homes that hitherto had been difficult to heat from room to room.
Over the years, technologies and heating systems have improved, mainly regarding the boiler. The modern, condenser combi-boiler for example, is now much smaller than the original boiler from the 1930s central heating system.
Radiators were once large, bulky items and although the modern version is more slimline, they are still noticeable in a room. But their location is not always the best – under window sills, for example, can make dressing the window more problematic, or they are located in the centre of a wall, making furniture placement in the room more difficult than it needs to be.
But with underfloor heating, you have the distinct advantage of everything being hidden away. The boiler can be hidden away in a cupboard, the manifold hidden from view and the piping is laid sub-floor, and so nothing of the heating system is on show.
#2 Even Distribution of Heat
There is another problem with radiators – uneven heat distribution. Radiators heat the air in the room which, as it warms, rises to the ceiling and then falls back to the floor as it cools. This happens throughout the room, but the radiator concentrates heat in one spot. As the motion of hot air cooling is a circular one, it happens most effectively at the source of the heat, in this case, the radiator.
And neither is it very good at going round corners, and so any awkward ‘nooks and crannies’ in a room can feel quite cool compared to the rest of the room,
Underfloor heating doesn’t head the air, known as convection, but by heating solid objects, such as the floor and your feet. This is a form of radiated heat. Materials with a high conductivity can grab and hold onto the heat much better, and this means your room or rooms are heated well.
But, as the sub-floor piping is laid in loops throughout the floor, there are no cold spots and no hot spots. Better still, in rooms such as the kitchen, the piping is laid in places where it will be of use such as the main floor area and not wasting heat under cupboards.
Likewise, in high heat loss areas, such as in front of the patio doors, piping can be ‘doubled up’ so that there is more heat output in that area.
#3 Efficient Way to Heat a Room
Wet underfloor heating is a system that runs all the time. But this doesn’t mean that your heating bill will skyrocket;
- Firstly, the heat from the heat from the hot water circulates through the piping, heating the screed or insulated boards around it.
- Secondly, floor insulation beneath the system stops heat being lost to the ground and this means all the heat makes it into the room above.
- Thirdly, because it can be controlled, you can turn the system down to provide a low-level maintenance heat when you don’t need a high level of heat. When you do ask for more heat, it won’t take too long for the room to reach the desired temperature.
- Fourthly, each underfloor heating system is designed for the property to consider door areas, the layout of fitted furniture and components. This prevents heat being wasted heating places that it doesn’t need to.
- Fifthly, it uses less energy to deliver a lower-level but comfortable level of heat.
#4 Works at a Lower Temperature
Over the years, there have been various pieces of advice regarding the ‘right’ temperature for in the home. Being cold is not good for health and so a home that is warm is essential. But some homes hold onto heat better than others.
Central heating provides a fantastic level of heat but with energy prices rising on an annual basis, it is hard to see how you can maintain heat your home on a budget.
Underfloor heating provides a healthier heat as it doesn’t dry out the air but alongside other components within the system, its lower working temperature doesn’t place you at a disadvantage;
- Insulation – underfloor heating should be installed in a property with the best insulation measures possible, including floor insulation. This stops heat being lost.
- Flooring material – flooring that has a high conductivity means that it holds onto heat for longer and this too contributes to a more efficient heating system.
Combine these two points and you have a heating system that doesn’t need to run at a high temperature because your home stays warmer, for longer. It consumes less energy too and thus, running at a lower temperature for longer is one reason why people invest in underfloor heating.
#5 You Can Install It Yourself
You can save yourself even more money by installing your own wet underfloor system. It really isn’t that complicated;
STEP 1 – Choose the right heating system for you
From single zones (one room or across the whole of the downstairs for examples) or a multi-zone system, choose the pack that is the right size for the floor space you are covering. Most manufacturers and suppliers offer complete kits by the square metre of floor space the piping will cover. There are also ultra-slim, low-profile kits that make retrofitting the system in a property super-easy.
STEP 2 – Strip back the floors
Once you are confident you have the right kit, strip back the top layer of flooring to the sub-floor. Make sure this floor is clean and free from debris.
STEP 3 – Lay the floor insulation
The type of floor insulation will depend on the kit you are using. Some kits, for example, come complete with insulation boards and pre-routed sections for you to lay the piping loops.
STEP 4 – Lay the piping
Once you have the correct insulation in place, you can start to run the plastic piping in loops from one end of the room to the other. Our kits come complete with comprehensive instructions so you get this section of the installation correct. Always start from the manifold, running the pipe away and then looping it back. Check TWICE before you cut the pipe! Tack the pipe in place.
STEP 5 – Lay the screed
Fill the pipes with water so that they stand firm once the screed has been applied (and this is also a great way of checking for leaks). Again, different kits will come with different instructions and some will not use screed, a thin layer of concrete, but boards. Keep the water in the pipe whilst the screed dries.
STEP 6 – Call in a professional
All you need now is a Gas Safe registered to connect your underfloor heating to the boiler and an electrician to deal with the thermostat (although some engineers can do this too!) and that’s it! Your underfloor heating system is ready for action.
Not laying on a concrete sub-floor? Want to install underfloor heating in upstairs rooms with suspended floors? Not a problem – underfloor heating can be fitted to most flooring types.
#7 Cheaper to Run
We talked a lot about efficiency but it is worth looking at this again. As a heating system, there is no doubt that a wet underfloor heating system is cheaper to run than a radiator system;
- Controllable heat – by opting for a smart thermostat, you can be in control of the heat in your home every minute of the day and night, if you wish.
- Lower heat, for longer – as it runs at a lower heat, it doesn’t consume large amounts of energy at key times. For example, as you return home, you simply ask the system for a little more heat. With radiators, it may be heating your home from cold and it will take not only time to do so but consume a large amount of energy as it heats your home too.
- Insulation – suppliers and installers of wet underfloor heating systems will tell you how important it is to insulate your home so that it holds onto as much of the heat as possible. This includes loft insulation, wall insulation as well as floor insulation, and double-glazed windows and doors.
#8 Use Less Energy
Radiators, although you think deliver a great source of heat, deliver it inefficiently. They heat the air which rises and then falls and they heat one part of the room. But, more importantly, it uses a lot of energy to do so.
Underfloor heating, by contrast, uses very little energy overall to deliver a stable and constant level of heat. As it delivers the heat evenly throughout the room, it uses less energy. Match this with the right flooring solution and you have a room that holds onto heat for longer.
Your home will not become cold or chilly. Even running at a low-level ‘maintenance’ temperature, your home will not become cold, leaving your boiler to consume a lot of energy to heat the home when you need it most.
#9 Allergies and Hygiene
You may not think of your current system as adding to allergies and hygiene issues within the home, but it does. Underfloor heating, however, has many advantages when it comes to allergies and hygiene;
- Hard flooring – the best flooring solution for an underfloor heating system is a hard floor. This is because these materials are better at conducting heat, although some are better than others. For you, it means a flooring choice that simple, easy and no fuss to keep clean. And we mean really clean: no dust, not dust mites, hair and so on to become ingrained in carpets, great news if you or family members are asthmatic etc.
- Radiated heat – convection, the process of heating air, causes the air to move. This means that microscopic pieces of dust and other detritus is airborne causing coughs and sneezes. Radiators cause air to swirl around but underfloor heating heats objects, such as the floor, and not the air. Thus, as well as keeping the floor hygienically clean, there is no swirling warm air to contend with either.
- No dust mites and bugs – bugs and mites love a centrally heated home. The damp in the carpet fibres combined with the heat of the home all make for great places for dust mites and bugs to live. If you suffer from allergies, this is great news because you will reduce the numbers of bugs and mites in your home dramatically.
With so much going for it, you can be forgiven for thinking that underfloor heating is simply perfect. It is in many ways, but there are a few ‘downsides’ you need to be aware of.
#10 Increased Comfort
There is a principle called Passive House, a German concept that addresses how comfortable a property is. Essentially, this principle relates to heat in the home.
Radiators are hot, they heat the air drying it out and can make a home feel stuffy. Hence, you may open a window to ‘change the air’, effectively defeating the object by letting hot air out and cold air in.
Underfloor heating, much like the principle of a Passive House, is all about comfort. It doesn’t dry the air out but rather gently heats the room by radiating out from the floor beneath your feet.
There is also something luxurious and decadent about underfloor heating. Imagine stepping out the shower or bath onto a warm floor, or waking in a morning with a gently warm floor making sure your home is never cold, but not roasting hot either.
#11 You can zone your heat
It is true that you can switch heating off and on with radiators. However, the efficiency of this system is poor when compared to the zoning control you enjoy with underfloor heating. You can not only choose to heat a room, or not, you can also set a time for that heating to come at a point needed.
Imagine, you need your bedroom to be cool through the night to promote a good night of sleep, but you want your bedroom floor to be warmed for when you wake. You can time your underfloor heating to come on at exactly the right time – without the heating for whole house to need to strike up.
The significant benefit is your control over the cost of your heating. You only need to heat the parts of the house that you use at the time when you use it. if there is a guest bedroom, there is no need to heat this space until your family come to stay. If you want to heat the bathroom just for when you get out the shower – you have this control too.
#12 Decorate your home your way
Imagine being able to put your sofa anywhere. You do not need to worry about covering the radiator, as there is no radiator.
That bulky piece of metal and piping can never be satisfactorily managed. It is one of those burdens faced by an interior designer – where practicality gets in the way of the aesthetic. You can build a cover with some flourish, but this means you lose even more floor space and break into the clean lines you hoped to create.
Underfloor heating is your invisible friend – it is discreet and so allows you to be stylish. It heats your home from beneath and so you have the freedom to decorate your home your way.
The Cons
Speed & Reactiveness
We are impatient. And in some ways, with central heating we have been ‘spoilt’ – simply ask the boiler for more heat and it delivers, instantly.
Underfloor heating is not quite the same. It takes longer to distribute an increase in temperature as it does to cool down. A radiator can heat a room in 20 to 30 minutes whereas an underfloor heating can take one to two hours to heat a room from cold.
This is why a smart thermostat helps you to be savvy about the level of heat in your home. Rather than switching off the underfloor heating system drop the temperature down to a maintenance temperature, such as 16°. And when you arrive home, asking it to reach a temp of 21° means it won’t take as long.
With a smart thermostat, you could also ask the system to start delivering more heat via an app on your phone.
Initial Installation Costs
One off-putting factor for many people is the initial outlay for installing the underfloor heating and its components.
Just like investing in a completely new central heating system, the initial outlay consumes a large slice of your budget BUT, with the savings you will make on heating your home, you will make this money back over time.
It is also worth considering that underfloor heating adds both value and desirability to your property too. This means that because your home is energy-efficient, it is cheaper to heat and for any potential buyer in the future, this is a plus.
How Much Does Underfloor Heating Cost?
It is the big question: how much can you expect to invest in a new, wet underfloor heating system?
Wet underfloor heating system costs will vary depending on;
- The heating system type and components you choose to use – some components are very expensive. As new technologies come to the market, the cost of various components decrease and this is why costs can be variable.
- Smart thermostat adds more to the overall cost – it may be more expensive than a run of the mill thermostat but a smart thermostat will give you more control over the heating system.
- Self-installation – installing the basics yourself (see Pro point 5!) will see you reduce cost significantly. Professional installation can be much more but worth it if you are unsure what to do. Our kits come with comprehensive instructions too, making installation easier.
- Cost per m² – complete kits often come costing a per m² and this makes it easier to work out which kit you need but also how much the system will cost.
- Start small… – the beauty of underfloor heating is that you could start with one room, and then lay the piping in the next room and so on, staggering both the cost of the installation and the work done on your home.
A single zone wet underfloor heating kit, enough to cover the floor area of a small bathroom can be as little as £285. Install-it-yourself multi-zone kits over large areas can be less than a £1,000. Just add the cost of professional installation if you are using a contractor.
And don’t forget, you will be saving money on your heating bill and this offsets any expenditure too.
In Summary
Underfloor heating is a tried and tested technology. Romans used it in their bathhouses and today, more and more people are increasingly investing in this kind of system to heat their homes and businesses.
It provides a gentle heat that stops your home being too chilly and too hot. It is also a simple system that can be installed in the major part by anyone with a smattering of basic DIY skills.
It is an affordable heating system both to install and run. Why not look at what wet underfloor heating can offer your home?
