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- Renovation
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- Hydronic heating
5 essential steps for implementing low-temperature heating in renovations
1. Do proper heat load calculations
85% of the current EU building stock was built before 2000, and 75% of those buildings have poor energy performance.1 Yet, in some renovation projects it’s still assumed that the existing insulation and building envelope are sufficient for low-temperature heating systems. This oversight can severely impact system performance. After all, poor insulation and air leaks increase heat loss, which makes it difficult for low-temperature heating systems to maintain the desired room temperature efficiently.
You can easily avoid this by carrying out a thorough energy assessment of the building before planning the heating system. This will allow you to identify areas with insufficient insulation and air leaks and will provide information about possible heat generators and emitters. Once the building is insulated to modern standards and heat losses have been minimized, a low-temperature heating system can be planned to combine comfort and energy efficiency.
2. Consider system compatibility
When retrofitting a low-temperature heating system, you need to evaluate its compatibility with the existing radiators and pipework. Many existing heating systems were designed for high-temperature operation with traditional boilers. But, if these components are incompatible with a low-temperature system, their performance will suffer, leading to inefficiency and uneven heating.
To avoid this, you must evaluate the suitability of the existing infrastructure. You need to ensure, for example, that the radiators are appropriately sized to work with lower water temperatures and replace them with low-temperature-compatible options if necessary. The pipework also needs to be reviewed taking into account the emitters that will be used. A fan coil unit, for example, needs a water volume that is 2 to 4 times higher than a standard panel radiator. Consequently, the minimum required pipeline diameters are higher. If the pipes are undersized, the water flow to the units will be insufficient, causing the output to be lower than required.
Read about 3 features to keep in mind when installing a fan coil unit
3. Size the heat source and emitters correctly
Oversizing or undersizing the heat pump or boiler for the space that needs heating can lead to reduced efficiency and a shorter lifespan. The same goes for the emitters. An undersized system won’t be able to meet the building’s heat demand, while oversizing leads to energy waste. Moreover, both cases create an uncomfortable indoor climate.
A crucial factor is the design temperature of the heating system. In old systems, the flow temperature is often 70 °C or higher. However, with condensing boiler technology, and even more so with heat pumps, the system temperatures are much lower. This means that the old radiators, which were designed for high temperatures, may no longer be suitable.
Incorrect sizing can easily be avoided by performing precise heat demand calculations for every room. Specialists who perform these will consider factors such as insulation, window quality, and the local climate to choose the correct heat source and emitter size. This will ensure optimal performance and energy efficiency.
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4. Remember to adjust flow rates and balance the system
In some renovation projects, flow rate adjustments are overlooked when a low-temperature heating system is implemented and the system isn’t hydronically (re)balanced. Nevertheless, this is an important step as incorrect flow rates or imbalanced circuits can cause uneven heating, reduce efficiency, and lead to cold spots in the building.
With the help of thermostatic radiator valves or balancing valves, you can calibrate the system to ensure an optimal flow rate for each radiator. Hydronic balancing is always important to ensure that all radiators receive the required amount of water to transfer the required heat output. Compared to condensing boilers, heat pumps have a smaller delta T, which leads to a higher flow rate. This must be taken into account when calculating the pipework.
Read more about the role of hydronic balancing in energy-saving
5. Think about controls and user education
Finally, it’s important to not forget about the controls. You can install the best-fitting heat generator and emitters, but without intuitive controls to manage the low-temperature heating efficiently, you’ll end up with a system that consumes more energy than required and is unable to perform as planned. Moreover, when installing a new system, it’s vital to provide adequate user education. If this is overlooked, end users may struggle to understand and operate the system properly, which in turn can lead to frustrations and higher energy consumption.
By recommending user-friendly smart controls or thermostats that allow for easy programming and remote management, you create a fully connected system that can easily be tailored to the user’s needs and habits. If you then also provide clear instructions and training for the clients on how to use the system effectively, it will empower them to optimise system performance and energy savings.
Learn more about our Unisenza Plus controls
Conclusion
Low-temperature heating systems can certainly help to improve energy efficiency and reduce emissions in renovation projects, but only if they are implemented correctly. Following the steps discussed above is vital for ensuring a successful installation and proper operation. If you have any questions about our low-temperature heating solutions or would like our advice on how best to integrate them in your renovation project(s), please don’t hesitate to get in touch with our experts.