Air Source Heat Pumps & Underfloor Heating: Your Guide

Underfloor heating is an excellent complement to an air source heat pump. As the needed flow temperature falls, the efficiency of an air source heat pump increases. Simply said, the colder you can run the system, the less it costs to operate. 

 Underfloor heating can operate at very low temperatures if correctly planned and installed. As a result, underfloor heating and air source heat pumps are an ideal match for UK homeowners. 

If you require an MCS Certified heat pump & underfloor heating installer in Portsmouth, Southampton or anywhere else in Hampshire or West Sussex, call Clean Heat Solutions at 07391473964.

Why do air source heat pumps work with underfloor heating? 

Underfloor heating systems have a greater heat emitter area, thus they have a far wider heat exchange surface than a standard radiator, which may take up one or two square metres on your wall.

Let's take a closer look at how heat emitters function... 

Heat emitters are concerned with the temperature difference between the emitter and the target room temperature. As a result, if your heat emitter is set to 60 degrees and you want to keep the room at 20 degrees, a tiny radiator will do the trick, albeit inefficiently. In this situation, the system will have to work overtime to keep the temperature so high. 

Installing a larger heat emitter (underfloor heating or oversized radiators) allows the system to be run at as low as 30 degrees while still maintaining the necessary 20 degrees in the room. Because the system operates at lower temperatures, it is intrinsically more efficient.

Installing underfloor heating in your property

Would it be wise, in light of the greater efficiency, to install underfloor heating throughout the entire property, on all floors and in all rooms? This is determined by the structure of the building. It also relies on the project's nature. Let's dig deeper into this...

In general, installing underfloor heating on ground floors is simple for new construction and substantial renovations. It becomes more difficult on upper floors, and it isn't necessarily the greatest answer for small-scale refit jobs — which I will discuss further later.

The ground floor of new construction residences is often built on an insulated concrete slab, which is perfect for installing underfloor heating and is then covered with a screed. Installing underfloor heating becomes more difficult with a suspended timber floor. Screeded systems add significant weight, therefore joists will need to be modified to support the added load, which will incur additional costs.

Underfloor heating systems with a lighter overlay are an alternative, but they are less efficient than a screeded system (more on this later). They don't add much weight, but overlay systems can raise the floor by up to 50mm.

There are low-profile overlay systems available, however, the thinner pipes transport less water volume, which affects heat production when compared to a screeded system. Furthermore, you will still need to add insulation because heat will be lost if an underfloor heating system is installed over a solid floor.

These challenges are simple to fix if we can communicate with the project's architect and other stakeholders early in the process. Because each project is unique, please contact us if you have any questions.

Different heat distribution systems in different rooms

Because installing underfloor heating on suspended floors is difficult, a frequent approach is to have underfloor heating on the ground floor and oversized radiators on the upper levels of the home. As stated at the beginning of this article, standard-sized radiators are incompatible due to the tiny surface area necessitating a hotter system flow temperature. 

As the heat requirements for a bedroom are typically lower than those for other rooms, radiators do not need to be expanded to the extent that they would for a living room, and can be built to run at the same temperature as the underfloor heating on the ground floor.

Retrofitting underfloor heating for an air source heat pump

Retrofitting underfloor heating to an existing building that isn't being renovated extensively can be difficult; un-insulated solid ground floors can't handle underfloor heating since heat will be lost into the ground, and joist size and ceiling heights may limit alternatives for suspended floors. 

However, when installing an air source heat pump, underfloor heating is not necessarily required; oversized radiators can perform the job very well if constructed properly. 

It is impossible to cut corners and expect an underfloor heating system to perform efficiently - if anyone tells you otherwise, be wary of their motives. Because a well-planned radiator system can perform just as well as underfloor heating, it does not make sense to force underfloor heating into every project, as the implications could be costly.

What are the overall advantages of incorporating underfloor heating into your air source heat pump?

For starters, underfloor heating can run cold, allowing the system to stay efficient and not overwork itself. Furthermore, because there are no radiator units positioned on internal walls, there is more wall space and flexibility for innovative interior design and furniture configurations with underfloor heating. 

Installing underfloor heating with an air source heat pump makes sense for new construction and large-scale renovations. This is frequently the best option for future-proofing for a more efficient and sustainable way of life. It is, however, not the only choice. 

Underfloor heating can be expensive if done incorrectly. Assume that one room has an overlay system and the others have screeding. Because you can't receive as much heat through an overlay, the entire system has to run very hot to keep one room warm. As a result, to balance the system, you must turn down the other thermostats. This would reduce the overall efficiency of the heating system and make your heat pump less efficient.

Contact Clean Heat Solutions today to learn more about whether your home and heat pump installation are appropriate for underfloor heating. Our impartial renewable energy experts across Portsmouth, Southampton, West Sussex and Hampshire are here to assist you.