Out of the energy price trap, into independence via help of REPLACE
The EU-funded heating system replacement project REPLACE has developed tools that provide simple and competent assistance in the conversion to renewable systems.
Choose the right solutions for your renewable heat supply In the current situation, it is firstly particularly important that one or two technically applicable and suitable solutions for renewable heat supply are chosen when replacing the existing heating system. For this purpose, an easy-to-understand matrix in traffic light mode shows which renewable heating systems are well suited for which building type.
Take care of energy efficiency first
In the second step, even before sizing and installing the appropriate climate-friendly solution, take cost-effective energy consumption reduction measures that will significantly reduce both
- long-term energy consumption
- and the initial investment (as a smaller new system can meet the reduced demand) .
Such consumption reduction measures, regardless of the climate-friendly technology chosen, include
- thermal insulation of the top ceiling of the house. This saves 15-20% of the annual heating energy consumption of a single-family house and pays for itself in a few years.
- hydraulic balancing of the house’s internal heat distribution and radiator system. This involves adjusting the water mass flow in such a way that the heat (water) transport to each room is optimised and the temperature rise throughout the house is harmonised. This takes the installer half a day or a whole day and saves 5-15 % of the annual heating energy consumption.
- a window replacement, especially if the air tightness or thermal insulation is poor. The intervention is not excessive and can reduce heating energy demand by 20-25% and increase living comfort substantially.
Together with the two measures mentioned above, heating energy consumption can be more than halved. This is considerable – also in relation to the initial investment for the new climate-friendly system – regardless of the technology chosen.
Especially if a modern heat pump (HP) is desired, no district heating is available or no biomass combustion/storage or delivery is possible – should be considered:
- Make sure that the flow temperature of the in-house distribution system is below 45°C – so that the HP can sufficiently exploit the possible efficiency gains due to the technology. If you are lucky enough to have underfloor, wall or ceiling heating, you will also be able to get by with 35°C or less.
- If your house has radiators (often with 50-70°C flow temperature), a prerequisite for meeting the 45°C criterion is that the house’s heating energy consumption is sufficiently reduced by the measures described above so that the existing radiators can keep the house warm enough even with a significantly lower flow temperature. Please consider also: Every single degree of flow temperature below 45°C saves another 2% of the annual electricity demand of the HP. You can reduce heating energy consumption even further either by further thermal refurbishment of further parts of the building envelope (façade, cellar, exterior doors etc.) or by fitting fans to radiators or installing larger radiators.
- The domestic hot water heat demand (this requires a flow temperature of at least 55°C) of a heat pump heating system can be covered more efficiently with the support of a PV system (and an electric heating rod in a sufficiently dimensioned hot water tank). Alternatively, a solar thermal system with an even larger hot water tank can be an appropriate solution.
- Another measure of particular interest to HP is the installation of a small peak-load (hybrid) heating system (e.g. a wood tile stove or designed pellet stove in the living room) as a backup for very cold days. Typically, the maximum heating load only occurs on about 6 out of (depending on climate) 180 to over 200 heating days and 80% of the heating load only occurs on about 20 days. It is most efficient if 20% of the upper heating load is contributed by a back-up system on the less than 30 coldest days of the heating season. This allows the HP to be sized even smaller and becomes both cheaper and more efficient (as the operation of the HP is most inefficient on the coldest days).
Select a climate-friendly, financially attractive, and economic resilient solution
If you want to economically assess your own heating replacement project, you can use the REPLACE calculator. In three steps, users get directly to the result based on their own heating demand, the type of system installed, and after selecting locally available/possible fuel/energy supply options. The result shows only climate-friendly heating systems. Their annual heating costs as well as the cost and CO2 savings compared to the existing heating system are displayed. The tool runs without prior knowledge on the basis of economic default values and available investment subsidies of the selected region. Users also have the option of entering their own real or project-specific investment and subsidy data and running costs (e.g. existing and future fuel prices as well as maintenance and repair costs) for each technology considered. This also allows you to compare concrete offers from installer companies.
If you have paid attention to the principle of “energy efficiency first” and selected a competent installer with experience in sizing and implementing high-quality heating equipment, you should have realised a project that will make your home independent and price resilient even in uncertain times. In addition, combined heating with logs and pellets in two separate combustion chambers in one heating system is also conceivable. This makes you flexible in case of price changes, if you opt for biomass and like to handle logs. A PV system is a perfect match for a reversible HP system that also cools your house in summer.
You can find more information about your options in our heating exchange handbooks. Two handbooks are aimed at end customers on the one hand and professionals on the other, and guide them through the process of heating replacement each time. There you will also find some useful recommendations on how to reduce your overall heat consumption. For example, every single degree lower in room temperature (e.g. 22°C instead of 23°C) saves 6% of fuel consumption during the period of lowered room temperature. If the thermostat is set to 21°C instead of 24°C over the heating period, you will save 18% fuel over the heating period. In times of high fuel prices, it may be worthwhile to wear a long-sleeved shirt in winter instead of always just a T-shirt.
Finally, Best Practice Examples are available, showing realised examples from eight European countries, ranging from Western, to Central, and South-Eastern European examples.
About REPLACE
REPLACE is a research and innovation project. It’s online tools are used together with regional campaigns such as the establishment of information points, support for community actions such as the procurement of insulation material or excursions to good practice examples. The project has one main goal, which is to motivate and support people in eight different countries to replace their old systems with greener alternatives based on informed decisions. Simple renovation measures that reduce overall energy consumption are also part of the programme. After five years of implementation of the campaign, 144,000 tonnes of greenhouse gas are expected to be saved annually. The Austrian Energy Agency is leading the programme, which is funded by the EU under the Horizon 2020 programme. In total, 11 project partners in eight countries are joining forces to make heating and cooling in Europe cleaner and more efficient. The countries where REPLACE is in operation are Austria, Bosnia and Herzegovina, Bulgaria, Croatia, Germany, North Macedonia, Slovenia and Spain.
