Having a good, energy efficient heating system is one of the most important elements to this renovation for us. We want to be able to have a home that in the future is able to be completely self-sufficient on energy and heating, whilst still keeping greenhouse gases to a minimum (or eliminating them completely). Insulation is a really important part of this system because once you generate heat you want to keep it in the building! Our overall plan is to create a heating system that could be run off mains electricity initially. Then easily converted to our own sustainable energy down the line when we are able to afford that next investment.
Choosing our heating system
When we first got the keys to our home it didn’t have an existing heating system other than two open fireplaces. Although we will restore these and put in log burners for a back-up heating source, we didn’t want to go down this route for daily use. We are conscious of the amount of wood, and therefore trees, that would need to be cut down to be able to keep the house heated in the winter.
Instead we decided to install an underfloor heating system with an air source heat pump supplying the warmth. We chose underfloor heating as it could heat the entirety of the home evenly without the need of installing radiators on the walls or similar. We loved the idea of an air source heat pump since they are so easy to install. They also produce a lot of heat output.
The heat pump takes the heat from the air around it and heats up the water in the underfloor heating pipes. It only takes 2.3kW of energy (electricity) to produce 10kW of heat. As it doesn’t burn anything, and only uses electricity, it is easy to make it a completely clean heating system (no emissions into the air) once the electricity needed is generated from a renewable source. In the future we plan to switch to our own renewable energy production. We will only need to produce 2.3kW of electricity ourselves to be able to have a 10kW heating system.
Insulation, insulation, insulation…
Before installing this new heating system, it was time to invest in insulation. You can have the most powerful heating system in the world but if your home has no insulation the heat will quickly disappear outside. We first focused on the loft insulation. The previous owners had started the loft insulation, insulating about half. They even had some existing rolls of mineral wool insulation left for us to use. We utilised the materials left for us before buying more in order to completely insulate the loft. The mineral wool we felt was a great choice because of the balance between it’s effectiveness, the financial cost and also the ease of fitting.
As we were having an underfloor heating system, it was really important that we fully insulated the floor so the ground underneath did not absorb the heat instead of heating up the house. After a lot of research, we decided to opt for expanded polystyrene insulation. Despite this being a form of plastic, we felt it was a brilliant option for us, for the following reasons:
1. It doesn’t have a high carbon footprint to be made compared to other insulations.
2. It’s made locally (to us) and also lightweight, so the carbon footprint of transportation is low.
3. It’s very durable, so it doesn’t lose its insulation properties over time. This makes it more efficient in years to come.
The only material that matched up for us was cork, but sadly the price of it made it completely unattainable for the amount we needed, but in a perfect world we would have gone for cork.
As our house is made of stone we wanted to enjoy some of the stone whilst still having a well insulated home, so we have decided to keep some stone walls exposed whilst insulating the rest. We feel this is a good balance of getting to enjoy the character of our old home, but still having that heating efficiency that is so important to us. We chose a combination of the expanded polystyrene insulation and rock wool insulation depending on the size of insulation needed.
Installing the underfloor heating system
The next step was to lay all the pipes. This was very simple to do and only took one day for the whole downstairs area of the house (75 m2, 807 sqft). We had a family friend who is an expert come and help us do this. He made sure the system was done in a way that heating could be turned on/off in certain areas. These pipes have a guarantee of at least 50 years, but could easily last 100 years. Having a system that we know will be durable and last is so important to us. If we had to replace it, it would be so energy intensive and wasteful.
We laid the pipes and attached them to the manifold, which we used an old wooden pallet to mount. We then we hired in professionals to lay the screed over the top of the pipes. It was important to hire professionals for this job as we needed the floor to be completely level and flat. This is a type of cement, and although not the most eco-friendly material choice, it is very durable and effective at transferring heat. We hope that the amount of energy we will save by installing this type of system will outweigh the carbon footprint of installing it.
The last step after the screed had fully dried is to lay our flooring. We chose tiles over other flooring options because they are fantastic conductors of heat. This will really maximise the amount of heat we were able to get into the room.