Heat pump: Efficient heating for old buildings
Is a heat pump suitable for old buildings? This question is asked by many renovators who want a sustainable, efficient and cost-effective heat supply. The simple answer: yes. In principle, a Carrier heat pump can be used in old buildings. However, when it comes to efficiency and heating costs, there are a few points to bear in mind. We will show you what these are and how you can also heat your existing building cost-effectively with environmental heat.
Why the heat pump is suitable for old buildings
A heat pump from Carrier makes free environmental heat usable for heating. This is possible thanks to an electrically driven process in which a refrigerant is repeatedly evaporated, compressed and liquefied. In this way, it is possible to raise the temperature level of the environmental heat and supply the heating water with thermal energy. Whether this process takes place in a new or existing building is fundamentally irrelevant. This means that you don't have to freeze with an environmental heating system in an old building. Because you can achieve the desired room temperatures very comfortably even in the depths of winter.
Heat source and flow temperature determine consumption
How much electricity is consumed depends on the temperature range. This describes the difference between the temperature of the ambient heat source and the flow temperature in the house. The closer the two are to each other, the less electricity the heat pump consumes in the old building. To save costs, you should therefore ensure a small temperature range. Once the choice of heat source has been made, the best way to do this is via the flow temperature. In many cases, this can be lowered with simple measures. If the flow temperature is between 50 and 55 degrees Celsius, the technology can be considered from an economic perspective. If you lower the temperature further, you save around one to two percent of your heat pump heating costs for every degree Celsius.
Benefit from many advantages with a heat pump in an old building
Heat pumps and old buildings: not only do they work together, they also offer numerous advantages. You can heat more cheaply with optimal planning. You become independent of the CO₂ tax and no longer suffer from the fluctuating prices of fossil fuels. Electricity usually comes from your own country and increasingly from renewable energy sources. This makes the energy source more future-proof and climate-friendly than many others. Another advantage: the state reduces the cost of heat pump technology by offering attractive subsidies. There are currently subsidies of 30 to 70 percent, which you can combine with a low-cost supplementary loan. It is also possible to cool your home with a heat pump from Carrier. You have the option of using your own PV electricity for heating and cooling and can save even more this way. The following overview shows the most important advantages of a heat pump in an old building:
- Low heating costs with optimal planning
- Independent of fluctuating energy prices
- No CO₂ tax for heating with electricity
- Future-proof and climate-friendly energy source
- Subsidies reduce the costs of heat pumps in old buildings
- Heating and cooling with heating and panel heating system
- Greater independence through integration of a PV system
Your building should meet these requirements
If you opt for a Carrier heat pump for your old building, the building should meet a number of requirements. This will ensure that heating costs remain low and the system runs reliably. The following overview shows the requirements at a glance.
Correctly setting the heating characteristic curve of the heat pump in an old building
The most important requirement is not so much the house as the heating system itself. For efficient operation, it is important to set the heating characteristic optimally. This refers to the function of the control system, which assigns an individual flow temperature to each outside temperature. If the characteristic curve is too high, the heating consumes more electricity than necessary.
Tip: Read our guide to setting up your heat pump correctly to find out how to set up your system for particularly efficient operation.Hydraulischer Abgleich des Heizsystems für mehr Effizienz
Hydraulic balancing of the heating system for greater efficiency
Regardless of the type of heat transfer, hydronic balancing plays an important role for heat pumps in old buildings. This is because specialists adjust the heating network so that all heating surfaces are supplied with the required amount of heat. In an unbalanced heating system, the flow temperatures are often too high to compensate for the undersupply to remotely connected rooms. This in turn results in high electricity and heating costs.Zu kleine Heizflächen durch größere Heizkörper austauschen
Replace heating surfaces that are too small with larger radiators
A Carrier heat pump for old buildings also works without underfloor heating. However, it is important to replace unfavorable radiators with larger ones. These are often only a few and the flow temperature can be lowered significantly. Due to the comparatively low costs, the measure usually pays for itself quickly. Flächenheizung mit der Wärmepumpe im Altbau nachrüsten
Retrofitting panel heating with a heat pump in old buildings
You can achieve the optimum in terms of comfort and efficiency with panel heating. This transfers heat to the room over a large area and therefore requires a lower flow temperature. This lowers the required temperature range and reduces the costs of the heat pump in the old building. In addition, comfort is increased by the even heat radiation from the floor, wall or ceiling.Teile Ihres Gebäudes dämmen oder alte Fenster austauschen
Insulate parts of your building or replace old windows
To further reduce your heating costs, you can also consider an energy modernization. This is often not absolutely necessary, but is definitely beneficial for the efficiency of the heating. Measures such as loft insulation or basement ceiling insulation are particularly recommended. This is because they already provide measurable savings and are often easy to implement yourself.
By the way: The annual coefficient of performance (COP) can be used to determine whether a heat pump is working efficiently in an old building. This describes the ratio of the amount of heat emitted to the amount of electricity consumed and should be three or higher. If this is the case, the system provides three kilowatt hours of heat with one kilowatt hour of electricity.
Which heat pump for an old building: tips for choosing
The best heat pump for an old building is one that is individually planned and set up. This is because it allows you to cover the heating requirements in the house without having to accept excessive heating costs. Incorrect design, on the other hand, is often the reason for dissatisfaction and excessive expenditure. We therefore recommend that planning is carried out by specialist tradespeople or energy consultants.
Air-to-water heat pumps are easy and inexpensive to install
When it comes to the type of heating, air-to-water heat pumps are often recommended as they have the lowest purchase costs. Although they achieve a lower COP compared to brine or water-to-water heat pumps, they can be installed almost anywhere - regardless of whether they are split appliances or monobloc heat pumps for outdoor installation.
Cascades efficiently supply multi-family houses with heat
If you are looking for a heat pump for your old multi-family house, a combination of several appliances is often suitable. These can be connected to form a cascade and used together to generate heat. The ability to switch the appliances on and off flexibly results in a wide control range and the system works reliably and efficiently in all conditions.
A heat pump in an old building: costs and subsidies
It is not possible to make a general assessment of how much it will cost to retrofit a heat pump. This is because it depends on influencing factors such as the type and size, as well as the additional measures required. You can therefore only obtain binding information with an individually calculated quote from a specialist installer.
30 to 70 percent subsidy plus favorable supplementary loan
But remember to apply for subsidies. If you do this before you start work, you can hope for a grant of 30 to 70 percent. If you also apply for a low-cost supplementary loan, you can cover the costs of the heat pump in the old building in full and get your new eco-heating system without making large savings. Grants and loans are awarded by the Kreditanstalt für Wiederaufbau (KfW). While you can apply for a grant directly online from the development bank, you can contact your bank for a development loan. Important to know: To be able to apply for the loan, you absolutely need a heat pump subsidy approved by KfW.
