Air Source Heat Pump and Underfloor Heating
Compared to traditional gas boilers, heat pumps are a more sustainable source of heat for home heating systems and are ideal for use with underfloor heating. In this expert guide, we'll explore the energy efficiency of heat pumps and find out which underfloor heating systems are best suited for use with heat pumps. You will find:
1. Why does underfloor heating work with an air source heat pump?
2. Install underfloor heating in your property
3. Different heat distribution systems for different rooms
4. Add floor heating to the air source heat pump
5. What are the overall benefits of installing underfloor heating for your air source heat pump?
Why does underfloor heating work with an air source heat pump?
Underfloor heating systems have a larger area for heat dissipation, so underfloor heating has a very large heat exchange surface compared to traditional radiators that may occupy a square meter or two on the wall.
Let's take a more detailed look at how thermal emitters work...
A thermal emitter is about the temperature difference between the emitter itself and the desired room temperature. So if your radiator is running at 60 degrees and you want to keep the room at 20 degrees, a small radiator will do the job, albeit inefficiently. In this case, the system will work very hard to keep the temperature so high.
If you install larger heat radiators (underfloor heating or oversized radiators), the system can run as low as 30 degrees and you still get the desired 20 degrees in the room. Since the system operates at lower temperatures, it is inherently more efficient.
Install underfloor heating in your property
Is it wise to install underfloor heating throughout the hotel, on all floors and in all rooms, given the increased efficiency? Well, it depends on the structure of the building itself. It also depends on the nature of the project. Let's explore in more detail...
In general, installing underfloor heating on the ground floor is straightforward for new builds and large-scale renovations. It becomes more challenging for higher floors, and it's not always the best solution for small-scale remodeling projects - I'll get to that later.
In new build properties, the ground floor is usually built on an insulated concrete slab, ideal for installing underfloor heating, which is then covered with a screed. However, installing underfloor heating with suspended wood floors becomes more challenging. The screed system adds a lot of weight, so the joists need to be upgraded to handle the extra load, adding to the cost.
Lighter underfloor heating systems are an option, although they tend to be less efficient than screed systems (more on that later). They don't add any significant weight, but the cover system will add up to 50mm of floor height.
Low profile mulch systems are available, but thinner pipes carry less water, which reduces heat output compared to screed systems. Also, you'll still need to add insulation because if you cover your underfloor heating system over a solid floor, heat will be lost.
These issues are easily resolved if we can reach out to the project's architects and other stakeholders early in the process. Every project is unique, so please contact us if you have any questions.
Different heat distribution systems for different rooms
Due to the challenges of installing underfloor heating on a suspended floor, a common solution is to install underfloor heating on the ground floor and oversized radiators on the upper levels of the property. As described in the introduction to this article, standard size heat sinks are not compatible because of the smaller surface area and the need for higher system flow temperatures.
In most cases, the heat needs of the bedrooms will be lower than the other rooms, so the radiator doesn't need to be oversized like the living room, and can be designed to run the ground floor heating on the first floor at the same temperature as the other rooms.
Adding floor heating to an air source heat pump
Underfloor heating retrofits to existing properties that have not undergone major renovations can be tricky; uninsulated solid subfloors cannot be heated because heat is lost into the ground, and joist size and ceiling heights can limit suspended floor options.
However, underfloor heating is not always required when installing an air source heat pump - if designed properly, an oversized radiator can do the job well.
It's impossible to cut corners and expect an underfloor heating system to work effectively - if someone tells you otherwise, you should be very cautious about their motivations. Since a radiator system can work just like underfloor heating if properly designed, there is no point in cramming underfloor heating into every project as the consequences can be expensive.
Conclusion: Floor Heating and Air Source Heat Pumps
What are the overall benefits of installing underfloor heating for your air source heat pump?
First, underfloor heating allows cooling, which helps the system remain efficient and not overworked. Additionally, the aesthetics of underfloor heating may be desirable as no radiator units are placed on the interior walls, allowing more wall space and flexibility for creative interior design and furniture placement.
For new builds and large-scale renovations, it often makes sense to install underfloor heating using an air source heat pump. This is often the best option when it comes to a more efficient and sustainable lifestyle for the future. However, it's not the only option.
Underfloor heating can be expensive if not done well. For example, let's say one room has a coverage system, while other rooms have screeds. Since you can't get as much heat through the cladding, the whole system needs to run very hot to keep a room warm. Therefore, you need to turn off other thermostats to balance the system. This affects the efficiency of your entire heating system and makes your heat pump less efficient.
If you would like to know more about whether your property and heat pump installation is suitable for underfloor heating, please contact us. Our renewable heat experts will give you the most professional advice.