Heat pumps: energy from the deep


In Switzerland, heat pumps are considered to be an important part of the energy revolution. This is because lots of renewable, environmentally-friendly energy is in the ground, in the water or in the air. Modern heat pumps make use of this energy. Here are our tips for heat pumps – for new builds and for retrofits.

Jürg Zulliger

Without thinking too much about it, would you be able to explain to a friend how heat pumps work? In their day-to-day life, many people are used to dealing with water or air pumps – but heat pumps? Let’s make it a little simpler: heat pumps work similarly to the cooling system in your fridge at home. Electrically-powered compressors raise the temperature and in doing so, they supply heating energy for buildings.

Types of heat pumps

Geothermal probes are used to make use of the heat that is present under the surface of the earth. Even on the coldest winter days there is often 5 to 10 degrees of heat at a depth of 250 to 300 metres (depending on the region and geology present). Depending on the model, heat pumps draw heat from the soil, from the surrounding rocks or from the groundwater. The energy is then conducted to the surface or into the heating system via a medium.

  • Brine-water heat pump: A probe positioned at a depth of 50 to 300 metres draws the heat from the ground.
  • Water-water heat pumps: make use of heat from groundwater or surface water.
  • Air heat pumps: these pumps draw heat from the surrounding air and do not require any drilling
Heat pumps: energy from the deep
Heat pumps create energy from the earth, from groundwater or seawater or simply from the surrounding air, as can be seen here. (Image source: FWS)

Heat pumps “What do I need to know?”

Heat pumps that create energy from the subsoil (brine-water) are particularly sustainable and efficient.  As is always the case when dealing with building, energy or modern facility engineering, it pays to have planned well. Ask yourself: what can be done at the site in question?

Andreas Baumgartner, senior consultant at the engineering company Amstein + Walthert had the following to say on the topic: “In densely built-up areas especially, you need to carefully consider what needs to be in place to permit a building to be retrofitted with a heat pump.”

One of the things you need to consider is the small amount of space that might be available. If you opt for the more expensive but more sustainable brine-water variant then you’ll need to consider whether probe drilling can be carried out on that property. Will the installer and the drilling company be easily able to use all their equipment and install everything that they need on-site?

You also need to consider your budget before you enter the planning stage. These days, many builders get their initial information from the internet or from catalogues. The expert Baumgartner said: “It is possible to buy a heat pump for a price of perhaps 12,000 Francs.

But with all the adaptations, building measures, connections and possible special drilling that may be needed, the final bill tends to be much more expensive than was thought. As a rule of thumb, the price for a detached house tends to be between 30,000 to 55,000 Francs for the planning, installation, heat pump and geothermal probe drilling. For larger buildings and apartment blocks or where particular geological problems are present, it can be more expensive.

Heat pumps: energy from the deep

Heat pumps: The most important tips for you

  • Permit: If you have a heat pump with a geothermal pump, it generally must be registered with the cantonal authorities and needs a permit. Air-to-water heat pumps set up outside require a building permit with proof of soundproofing.
  • FWS (Professional Heat Pump Association Switzerland) seal of approval: There is a seal of approval for inspected heat pumps, but also for drilling companies. We do not recommend buying products online, as the service and guarantee level leaves much to be desired. fws.ch
  • Recognised partners: You will find a list of several hundred fitters, suppliers and planners on our website. Fachverband Schweiz
  • Consultation: Please seek out the local energy advisory centre in your commune or your canton. In most cantons, there are financial incentives for converting to renewable energy and possible tax deductions. –Ask at your cantonal office or visit the website: energiefranken.ch
  • Planning: Planning, construction and assembly require a considerable amount of work. Be careful not to cause too many unnecessary expenses for the building (replacement of facade and windows, etc.) Ideally, the building insulation, inlet temperature of the heating and the heat pump all function well together. Ask your energy consultant or fitter!
  • System module: The FWS industry association, Energie Schweiz and other partners have created the heat pump system module. The certification guarantees quality and correct combined function of individual components, particularly for small systems in private homes. See: System module
  • Photovoltaics (PV) Check whether you can combine your heat pump with self-produced solar heating. In general, self-produced solar energy from can be stored in batteries on the roof. This saves costs on grid power and is an important step in the direction of sustainability.
Heat pumps: energy from the deep
Heat pumps are very efficient and sustainable: They deliver 100% usable heat from a third of operating energy, e.g. electricity. (Image source: FWS)

Switzerland at the cutting edge

By the way– Did you know that Switzerland is a world leader in heat pumps? No other nation has installed as many heat pumps per square metre as us! Switzerland also leads in the number of new constructions of heat pumps. Stephan Peterhans from the Professional Association for Heat Pumps (FWS) has the following to say on the topic: “Newly installed heat pump heating systems have a market share of roughly 90 percent.” In international comparison, this is an astounding figure. According to FWS statistics, 19,995 heat pumps were sold in Switzerland in 2017.