1. Is it true that UFH will take a lot of energy and time to heat up my house?
The amount of time and energy it takes to heat a house using underfloor heating depends on the construction build-up and the temperature that heating system runs at. If you have insufficient floor insulation at ground floor then underfloor heating would take a long time and cost a lot to heat your house.
You also need to consider the thermal mass of your floor construction, and where you put the underfloor heating pipes within it. Thermal mass describes a material’s capacity to absorb and store heat. A material’s thermal mass is affected by three factors: its specific heat capacity, its density and its thermal conductivity[i]. Materials like stone have a high thermal mass and can absorb and store large amounts of heat energy, whereas materials like timber have a low thermal mass and absorb and store low amounts of heat energy. Thermal mass can be a useful tool in regulating temperatures in buildings as they can absorb heat in the hottest parts of the day and release it in the cooler parts of the day, and many traditional forms of construction in warm climates take advantage of this. If you use thermal mass within the insulated envelope of a modern building it can help mitigate against internal temperature fluctuations in the same way, and can be a particularly effective tool to help manage summer overheating. This is important when thinking about underfloor heating, and the speed at which you want it to heat your house. If you place the underfloor heating pipes within a concrete screed then before the heating starts to heat your room, it will need to heat the concrete first. However once this concrete has been heated up it can store and release the heat energy over a period of time after the heating has been switched off. If you place the pipes in metal trays directly below the floor finish then the heating will heat the room quicker, but when you turn the heating off the underfloor heating will quickly stop radiating heat to the room.
The material you choose for your floor finish also has an effect on how quickly the heating will heat a room, with materials with high thermal conductivity (such as tiles) heating up faster than materials with low thermal conductivity (such as timber). It is important to understand these concepts when designing your underfloor heating system so that it meets your specific requirements.
Underfloor heating essentially turns your floor into a large radiator, so it works well with heating systems that run at lower temperatures, such as heat pumps.
2. Are there any smart home technologies that can help optimize energy usage and reduce waste?
Smart technologies are widely available and include heating systems, lighting, appliances and sockets. They can be used to control technology remotely, set timers and programme when technology turns off and on. Smart meters and smart sockets can be used to monitor energy consumption, so you can see which appliances use the most energy and adapt how you use them to reduce your energy consumption.
3. What are some eco-friendly lighting options that can be implemented in a home?
Firstly, use daylighting where possible – maximise the use of daylighting to internal spaces through window placement and rooflights. You can increase the effectiveness of this approach with light coloured and reflective surfaces.
Secondly, replace old lightbulbs with LEDs, which use up to 90% less energy than halogen bulbs[ii].
Finally, consider the number of light fittings you need and how you would like to control them. Being able to control fittings separately allows you to use more or fewer fittings depending on what the space is being used for and how much light is needed at any one time.
4. What are the most energy-efficient appliances and devices for a home?
Many household electrical appliances have an energy efficiency rating of A – G (this labelling system replaced the old labelling system in 2020), with A being the most energy efficient and G being the least energy efficient. Bear in mind that the ratings are based on the size of the appliance so a large appliance may have a better rating than a smaller one but still use more energy.
5. What are some sustainable heating and cooling solutions for homes that can save energy?
- Heating:
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- Heat pumps, ground source or air source, are a sustainable and efficient form of heating. They run on electricity which can be generated by renewable sources, and if you have renewable generation on site you can use this to help power your hot water or heating. Heat pumps are 300%-400% efficient which means that for each unit of electricity used to power the heat pump 3-4 units of heat energy are produced. Some heat pumps can also be used for cooling in the summer.
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- A Mechanical Ventilation with Heat Recovery (MVHR) system is an efficient way to help to keep your house warm. Modern buildings are designed to be more airtight than historic buildings. This is so they lose less heat through uncontrolled ventilation, but without adequate ventilation moisture, C02 and pollutants can build up in the air. Therefore, in airtight buildings, to have a good supply of fresh air mechanical background ventilation is required. MVHR systems, like standard mechanical ventilation systems, remove stale air and provide fresh air to buildings. However, in an MVHR system, the outgoing and incoming air is passed through a heat exchanger, which uses the heat energy from the exhaust air to heat the incoming air, which reduces heat loss through ventilation. The same process works in reverse in the summer when it is hotter outside than inside the house.
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- Passive solar gain is a useful tool in the winter in well insulated houses. Energy from sunlight enters the building through the windows, is absorbed by surfaces within the building, and is re-radiated as heat energy. If a building is well insulated it will retain this heat and it can contribute towards keeping the building warm. Buildings and extensions can be designed to capitalise on solar gain in winter (and to avoid excessive solar gain to stop overheating in summer).
- Cooling:
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- Designing for passive ventilation can help buildings stay cool in summer. This means designing windows with large enough opening lights, and designing buildings with openings on opposite sides to allow cross ventilation. Ventilation chimneys take advantage of the stack effect to draw stale air out and fresh air into buildings.
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- Solar shading can help to control unwanted solar gain in summer. Louvres and brise soleil are designed to allow low level winter sun into buildings and provide shading from high level summer sun. Installing external shutters can allow occupants to control solar gain in the summer whilst allowing useful solar gain in the winter.
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- Heat pumps can run in reverse and provide cooling in the summer months if the system is designed for this.
At Keystone Architecture and Design we are passionate about improving the sustainability of the built environment. We have the knowledge and skills to take a holistic approach to designing your new building or extension, ensuring you get a high-performance building with the spaces you need and the finish quality you want. If you are considering a high-performance new build, a Passive House project or retrofitting an existing property please contact us to see how we can help by email, phone or by using the contact form on our website.
07752 979244
[i] https://www.greenspec.co.uk/building-design/thermal-mass/
[ii] https://www.evergreenenergy.co.uk/led-lights/why-you-should-make-the-switch-to-led/#:~:text=LED%20technology%20is%20the%20next,dramatically%20reducing%20your%20lighting%20bills.
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