Hydronic Underfloor Heating
Hydronic under floor heating is a gentle ambient heating system and a luxurious way to heat your home if you’re building on a concrete slab. It’s like stepping from Winter into a warm Spring afternoon, providing the most evenly distributed and relaxed form of heating.
Hydronic In Slab Heating
In slab heating is a hydronic heating system installed using pipework attached to an internal wire mesh in the top part of a concrete slab. The pipes run in a continuous loop, so there are no joins, from a manifold location (a metal framework holding all the circuits of pipework and is connected to the heat source outside). It acts as the centralised point of the slab heating system and distributes the heated water slowly throughout the system when it’s running, creating q gentle all round heat. As the in-slab heating is a “closed loop system” it doesn’t require the use of fresh water instead recycling the same water around and around again.
The water running through a slab heating floor coils is never heated over 50°C so as not to damage the slab in any way which makes it compatible with many different flooring types. Polished concrete, tiles, laminate, natural stone and carpet are all perfect.
With in-slab heating, you never have to worry about placement of your furniture as there is no visible equipment apart from the thermostat and the manifold (which is hidden out of view in a cupboard). You also have the added advantage of being able to heat large areas without sacrificing wall space for radiator panels under windows. If you have floor to ceiling windows, then in-slab heating may be the best option for you.
Underfloor slab heating can also be “zoned” at the time of installation, so please discuss this with the sales representative designing your system in the early stages of design. For example, zoning means you can zone your large open living space as one zone and all of your bedrooms as a separate zone. These two zones will then have two different controllers and can be run independently or in co-ordination with each other.
Hydronic In Screed Heating
In Screed Heating works in the same basic way that In Slab heating works but has a couple of marked differences that make it superior.
In screed heating is installed under a second thinner layer of concrete on top of the structural concrete slab. Once the structural slab has been poured and the framework for the building has been built the in-screed foam matting can be put into place over the existing slab and the hydronic pipework circuits laid out.
When this is finished the concreters come back and do a thin screed pour of concrete over all the pipe and insulating mats. This needs to be discussed with the architect and builders at the time of design as you can’t retrofit a screed pour after the framework is in place because it lifts the height of the floor throwing out the window and door frame heights inside the building. So preplanning is essential!
The advantage of this matting is that it gives an insulated layer against the mass of the concrete slab. So when you turn the heating on, the heating only heats from the insulation layer up to the top of the concrete floor. This smaller volume of concrete being heated means a much faster reaction time and less heat loss, making it the most efficient way to heat your house as you aren’t heating the whole concrete slab.
What Are The Differences Between In Slab and In Screed Hydronic Heating?
Reaction Times - In slab heating will take longer to heat up but also longer to cool down as the hydronic pipe work coils are in the structural slab. In screed heating has faster reaction times as the hydronic pipe work is in the top (screed) layer only, which is insulated against the rest of the slab. So the difference is due to the amount of concrete that needs to be heated.
Energy Usage - Whilst both types of underfloor heating will use gas or electricity to generate the heat for the hydronic pipework, the long-term energy usage will be lower for in screed heating because it is only heating the thinner insulated layer of concrete rather than the whole structural slab.
Installation Costs - In slab heating will take longer to heat up but also longer to cool down as the hydronic pipe work coils are in the structural slab. In screed heating has faster reaction times as the hydronic pipe work is in the top (screed) layer only, which is insulated against the rest of the slab. So the difference is due to the amount of concrete that needs to be heated.
Retrofitting Underfloor Heating
The Minitec Hydronic systems are designed for renovations, helping to retrofit underfloor heating into existing structures.
With quick and easy installation, a rigid plastic sheet (11mm) is placed on top of the existing floor structure with pipe work (9mm) run between the raised knuckles, easily customised to fit around obstacles if necessary. With self adhesive backing and flexible Pex-A Pipe the job is done in no time, adding the renowned radiant heat of underfloor heating systems without significant increases to floor height or disruptive construction.
Once the system has been installed, there’s no need for any other layers or materials. Your installer can simply lay your desired floor finish on top and then your installation is complete! And the best part? Being such a thin layer under your floor means heat up times are up to 50-60% quicker than traditional underfloor heating systems, providing a comfortable warmth in just minutes.
What Are The Benefits of Underfloor Hydronic heating?
Allergy Friendly - Underfloor heating is allergy friendly with no dust created or forced by air movement. Hydronic heating uses hot water to heat your floor rather than recycling heated air throughout the house. This ensures that there are less allergens being circulated through your home, perfect for allergy and asthma sufferers.
Silent – Due to the fact that there are no moving parts inside the house (apart from the circulating water), underfloor heating is silent.
Versatility (zero profile) – The versatile nature of having the heating equipment inside the concrete slab means you can utilise all the floorspace in your home. This means you’ll never have to factor heating equipment into decorating and designing your dream home, placing furniture or interior wherever you like in your beautifully heated home.
Cost effective – Once installed the running costs of underfloor hydronic heating can be up to 35% more cost effective that other forms of heating. Because the concrete and water of the hydronic systems both hold the heat you will find that the heating lasts longer and doesn’t go instantly cold when turned off. The pipe work installed in the slab is also virtually maintenance free only requiring a regular general servicing on the boiler or Heat Pump.
Installing Hydronic Underfloor Heating
When it comes to installing Hydronic underfloor heating, don’t settle for second best. As one of Melbourne’s oldest and most experienced hydronic heating companies our professional team will co-ordinates with your builder to install the highest quality Hydronic pipe work prior to the final concrete pour. Once our pipe work is in place and pressure tested, the concrete is poured, and the rest of the building process proceeds.
As soon as the pipe work is laid down, we fill the pipework with water and leave it under pressure as to help support the pipework against the weight of the concrete. It also acts as a safety precaution in case there’s ever an accident and the pipework in punctured during the building process. The builder instantly knows that there’s a problem with the integrity of the hydronic pipe work if a wet patch appears on the slab. On the slim chance that happens our specialist service team can reattend and repair the pipework with a special clamping tool.
We then return at the very end of the build, to install the boiler or heat pump, plus to test and commission the system.
Frequently Asked Questions
Is it worth getting underfloor heating?
In our opinion the answer to that is a resounding ‘Yes”. The benefits of having a gentle, ambient, low energy, heating system, that is allergy friendly, low maintenance and also allows you to move your furniture around wherever you want to, speaks for itself.
How hot does the floor get?
The water that flows through the underfloor pipework never goes over 50°C because it can damage the slab. So whilst the floor will be comfortably warm it won’t be hot.
With under floor heating, it is not how warm the floor get it’s about the overall air temperature inside the house, with our systems designed to hold the temperature at a comfortable 21°C.
Do underfloor heating systems leak?
Once the pipework is covered with concrete it is very well protected. On the off chance one of the pipes get punctured during installation, the builder will know about it instantly as we fill and pressurise the pipes at the time of our installation. We have the ability to repair it using a special tool designed to clamp and fix the puncture.
All our pipe work is also covered by a 25-year warranty.
How much does it cost to run underfloor heating?
It is very difficult to answer this question as costs depends on how much you are paying for your gas/electricity supply, what temperature you have it programmed to run and the weather outside. If it is 4 degrees outside the heating will have to work harder to hold the temperature than if it’s 12 degrees outside.
Whilst hydronic is more expensive to install than a comparable sized ducted system it’s long-term running costs are less. It also stays warmer for longer because the heated water in the system holds the heat.
How long does in slab heating take to heat up?
If you have underfloor slab heating – Normally about 4 hours. It depends on how cold the slab is to start with and what the weather is doing outside.
If you have underfloor in screed heating – Normally about 1 hour. Due to the lesser amount of concrete the hydronic heating must heat.
How long does hydronic underfloor heating last?
Nissl Eichert only uses, what we consider to be the best equipment in the market. This ensures that our customers get the best value for money for their hydronic heating systems. The beauty of in slab heating is that once it’s installed, so long as it’s kept in use and maintained properly, the pipes inside the slab will last for multiple decades. Our current pipe work all comes with a 25-year warranty.
The boilers and heat pumps will need to be replaced and upgraded as the technology constantly evolves, improves and changes with the new models being so much more efficient than the older ones.
Can underfloor heating be zoned?
Yes, it can be. This needs to be discussed and designed early in the process of designing the system. A lot of our clients will have the main living area zoned independently to the bedrooms. Please be aware we normally cannot zone individual rooms. For each zone you need different controllers and a minimum surface area to be heated.
What flooring materials are compatible with hydronic underfloor heating?
Polished concrete, tiles, carpet and natural stones are all 100% compatible with underfloor hydronic heating with some engineered timbers also suitable. However natural wood is to be avoided due to the fact it stops the heat coming through and can split and crack due to the expansion and contraction.
Please discuss flooring options with the designer of your system, they will advise on what they would recommend and what to avoid.
Can I put natural wooden flooring over the underfloor hydronic heating?
No, that is the one type of floor covering you can’t put over slab heating for a couple of reasons. Wood is one of natures’ best insulators, so it works against the heat coming through from the slab. It also expands and contracts too much.
If you have your heart set on parquetry flooring, you may want to consider radiator panels as an alternative. If using an engineered timber floor please inform your flooring provider that the floor covering and it’s adhesive, will be on top of a hydronic heated slab.
What is a manifold?
A manifold is a metal framework that sits low to the ground on the concrete slab. It is the distribution point for the hot water coming into the house form the boiler/heat pump and it has all the flow and return pipes for the hydronic under floor heating centralised.
A manifold is usually located inside the bottom of a cupboard as we do need access to this in the future when servicing the equipment.