Retrofit heat pump: advantages, requirements and costs

Retrofitting a heat pump brings numerous benefits for the environment as well as for residents and owners of the house:

1. ENVIRONMENTALLY FRIENDLY HEATING

Heat pumps use renewable energies as a heat source (e.g. your own photovoltaic system on the roof) instead of fossil fuels. This means that no CO₂ emissions are generated on site, and switching to a heat pump also makes a valuable contribution to climate protection.

2. LOW OPERATING COSTS

Compared to conventional heating systems such as oil or gas heating, heat pumps offer high energy efficiency, which is directly reflected in your monthly operating costs. An air source heat pump uses one kilowatt hour of electricity to generate a total of four parts of heat for the house from the ambient air. In the long term, this means significant cost savings, which quickly offset the initial purchase and installation costs.

3. FUTURE-PROOF INVESTING

In view of rising CO₂ taxes on fossil fuel heating systems, a heat pump is a safe bet in the long term. Switching is already recommended.

4. INCREASE IN VALUE

Installing a heat pump can significantly increase the value of your property, especially in older buildings, as modern heating systems are increasingly in demand when selling or renting.

HEATING COMPARISON: HEAT PUMP VS. GAS/OIL HEATING

If you want to retrofit a heat pump in your home, several structural and technical factors need to be taken into account. The flow temperature, the condition of the building insulation and the space available for installation are particularly important. The existing heating system, for example classic radiators or underfloor heating, is also relevant.

THE RIGHT INSULATION

The quality of the building's thermal insulation plays a key role in ensuring that the heat pump's performance can be utilised with maximum efficiency. This allows you to protect the environment and save on heating costs.

You should bear this in mind:

• A flow temperature below 55 °C is ideal – this allows the heat pump to operate particularly efficiently.
  
• Well-insulated buildings require less heating power.
  
• Retrofitting is also possible in older, uninsulated houses – for example, through hybrid solutions.
  
• An individual renovation roadmap (iSFP) provides information about insulation quality and potential subsidies.

Our advice: Our powerful air source heat pumps with the environmentally friendly refrigerant R290 are an excellent choice for retrofitting a heat pump, as they have sufficient power to efficiently heat conventional radiators with flow temperatures of up to 78 degrees.

YOUR CURRENT HEATING SYSTEM

The existing heating system has a significant influence on whether and how a heat pump can be retrofitted.

• Underfloor heating systems are ideal for efficient use of a heat pump.
  
• Large, modern radiators are usually also suitable.
  
• Traditional ribbed radiators can work if they are sufficiently dimensioned.
  
• Hydraulic balancing improves efficiency and is usually a prerequisite for subsidies.

SPACE REQUIREMENTS INSIDE AND OUTSIDE

• Inside: space for hydraulic module, buffer storage tank, hot water storage tank if required
  
• Outside: installation area for the outdoor unit (for air-to-water heat pumps) with sufficient distance to the property boundary
  
• For geothermal heat pumps: space for ground collectors or approval for ground probe drilling
  
• Plan for noise protection, especially in close-knit neighbourhoods or terraced housing estates

Our advice: When retrofitting a heat pump, it is important to seek professional advice. Our alpha innotec experts will be happy to assist you.

Check building insulation

• The roof, walls and windows are (partially) insulated
• Heat loss should be kept to a minimum
  
• A renovation schedule is in place or planned

Estimate the flow temperature

• Ideal: below 55 °C for efficient operation
  
• Higher temperatures possible when using powerful models (e.g. with R290)
  
• Existing heating system already provides clues (underfloor heating or large radiators?)
  

Assess heating system

• Underfloor heating available? → ideal
• Old ribbed radiators? → possible with large dimensions
  
• Hydraulic balancing carried out or planned?
• Panel or surface radiators? → well suited
  

Clarify space requirements

• Inside: Space for hydraulic module, storage tank, buffer storage tank if necessary.
• Outside: Free space for outdoor unit (at a distance from the property boundary).
• Geothermal energy planned? → Space required for collectors or drilling.
  
• Consider noise protection (e.g. terraced house location)?
  

Seek expert advice

• Individual planning increases funding opportunities and system efficiency
  
• alpha innotec partners assist with selection, planning and installation

Basically, you can retrofit all types of heat pumps. The decisive factors when making your choice are the advantages and disadvantages of each system for you in terms of installation, the existing installation situation, the investment costs and, of course, the scope of the conversion work.

RETROFITTING A GROUND SOURCE HEAT PUMP

Ground source heat pumps, also known as brine-water heat pumps, use the heat stored in the ground. They are particularly efficient, but require ground probes or ground collectors and a suitable area. In densely built-up areas or in old buildings, retrofitting can be difficult.

Retrofitting an air source heat pump

Air source heat pumps, also known as air-to-water heat pumps, extract heat from the ambient air, even at temperatures as low as -20 °C. They can be installed almost anywhere and are particularly popular for retrofitting in older buildings. Although they are slightly less efficient, they are significantly cheaper to purchase and install.

THE SUITABILITY CHECK AT A GLANCE

The total cost of retrofitting a heat pump depends heavily on the type of heat pump installed, the structural conditions of your home and any additional measures that may be required. In addition to the device itself, there are also costs for accessories, installation, commissioning and, if necessary, adjustments to the existing heating system.

Compared to conventional heating systems, heat pumps are more expensive to purchase. However, they are significantly more efficient in operation and are supported by attractive government subsidy programmes. Retrofitting a heat pump is particularly worthwhile in energy-efficient modernised old buildings that are already insulated or have large heating surfaces, for example.

COST SCENARIO 1: HEAT PUMP IN AN OLD BUILDING (MODERNISED)

COST SCENARIO 2: HEAT PUMP IN a NEW BUILDING

Please note: The scenarios shown here are greatly simplified and are only intended to simulate an approximate cost framework. The exact costs depend on your property, the heat pump you choose and other circumstances, and may therefore differ significantly from the scenario shown here.

Retrofitting a heat pump is worthwhile for many homeowners. This is particularly true if the building already has solid insulation or is due to be modernised anyway.