Underfloor heating systems (UFH) are the ultimate choice of heating to work in combination with an air source heat pump.
But there’s more to underfloor heating than just pipes in the ground. Precise planning and design are essential for a comfortable home and energy efficiency.
Underfloor heating is around 55% radiant and 45% convection, creating a far more comfortable environment at much lower temperatures compared to a traditional radiator system.
7 Factors to think about with UFH
If you are considering underfloor heating, here are 7 important factors to consider before installation:
- The heat loss of your home (how much energy your home loses and how efficient it is)
- Flow temperature (how hot your system will operate at)
- Insulation in the floor build up
- The length of pipe in the floor
- The pattern of which the pipe is laid
- Floor coverings and their effects on efficiency
- Manifold locations (where the pipes will enter and exit in your home)
The heat loss survey
A full heat loss survey of your property will allow us to work out exactly how much pipework and what flow temperature is needed to maximise energy efficiency. We take into consideration all of the different room areas. This includes what each room is used for and the existing wall and floor coverings. This allows us to accurately calculate how much energy each property needs.
The goal is to operate your underfloor heating at the lowest possible flow temperature to achieve a comfortable indoor temperature whilst at the same time providing high energy efficiency. Underfloor heating systems can be installed throughout the entire house. When paired with a heat pump they provide even more efficiency.
Floor Insulation
Underfloor heating on a ground floor ideally needs to be insulated underneath. This stops any downward losses through the building fabric and any wasted energy. Current UK building regulations require downward losses to not exceed 10 watt per meter. A perimeter edging strip of 25mm is required to allow the screed or concrete to expand and contract during heat up and cooling down periods. This also stops any thermal bridging from the screed to the external walls.
What is the right underfloor heating system to work with a heat pump?
There are many different systems on the market, but many are not suitable for use with a heat pump.
With an air source heat pump system, a flow rate 4 times faster than a gas boiler is required. This means the correct sizing of pipework is essential to overcome the pressure loss at these much higher flow rates.
Smaller pipe sizing systems would require additional buffers, separation and potentially a larger heat pump to overcome. These are all important factors that affect the energy efficiency and usage. They also impact the costs to install and operate.
Careful considerations
It’s important to consider what output your underfloor system will have and if it can overcome the heat loss of your home.
Let’s take for instance a 16mm MLCP system in a concrete floor screed running at 45 degrees, the output per m2 will be 141.3 watts of energy.
If we take the same 16mm MLCP pipe but add in a reflective aluminium foil lined insulation and run at the same temperature of 45 degrees, the energy output is only 45 watt per m2. This is a huge difference.
Floor covering choices
The floor coverings you chose also have a massive impact on underfloor heating. This is often overlooked.
The choice of floor tiles, hard wood flooring or carpet has a significant impact on the efficiency of your underfloor heating system.
If you take the same 16mm MLCP system as above in screed at 45 degrees and based on floor tiles would provide 141 watts of energy per m2.
But if you swap those floor tiles for hardwood flooring, the output of that floor will decrease to 84.1 watts per m2.
Lastly, if a 1.5 tog carpet or maybe an engineered 22mm flooring, the same system will now only achieve 70 watts per m2. This is half the output originally achievable with floor tiles. It is therefore important to get this correct before any underfloor heating system is installed.
Get in touch
If you are considering underfloor heating or a heat pump, contact us today to ensure you get the best system possible.
* All energy and performance claims are based on our own energy assessments and live monitoring of energy consumption.
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