Heat pump installation in Sierre: A practical guide for homeowners

The city of Sierre, situated at an altitude of 524 meters, experiences 72 days of frost annually and a winter design temperature of -10 °C. These conditions require careful sizing of your future heat pump to ensure optimal comfort during the coldest periods.

With 2988 heating degree-days per year, replacing fossil fuel systems is a priority for reducing your carbon footprint while adapting your building to the Valais climate.

The ideal time to plan is before your current boiler reaches the end of its life or during a comprehensive thermal renovation. It is essential to check the schedule for the CAD Sierre network, managed by OIKEN, which utilizes industrial waste heat and sewage heat.

Before making a decision, verify if your neighborhood is eligible for connection, as this could be a more relevant alternative than an individual heat pump.

The technological choice for your heat pump depends primarily on your property and the power required to offset the local design temperature of -10 °C. Air-to-water heat pumps remain the most common, but their performance is directly correlated with your building's thermal insulation.

Proper sizing ensures the pump doesn't frequently rely on electric backup, which helps manage your annual electricity consumption.

Furthermore, integrating photovoltaic panels, favored by a global irradiation of 1451 kWh/m²/an in Sierre, can optimize your heat pump's operation. The estimated yield of 1277 kWh/kWc/an allows you to consume your own energy for heating.

Note that outdoor air-to-water heat pumps must strictly respect noise limits towards neighbors, a crucial point when placing the outdoor unit in dense residential areas of the Sierre region.

In Sierre, the building stock is heterogeneous, ranging from old stone Valais houses to buildings from the 1970s and 1980s. For houses built before 1990, an asbestos assessment is mandatory before starting any dismantling of old pipes or boilers.

Vested heating networks may also need to be upgraded to support the lower operating temperatures of a heat pump compared to gas or oil boilers.

Buildings from the real estate boom era often require reinforced insulation before installing a heat pump to ensure optimal efficiency. Without adequate insulation, the required pump power could be excessive, unnecessarily increasing investment and operating costs.

Always check the state of your internal heating circuit, as high-temperature radiators may need to be replaced with low-temperature emitters or underfloor heating to improve the seasonal performance factor (SPF) of your installation.

The municipality of Sierre is known for its energy commitment, having obtained the Energy City Gold label in 2019, renewed in 2023. This dynamic translates into strict energy planning guidelines.

Before beginning your procedures, contact the municipal urban planning department to learn about specific regulations for your area, particularly regarding the visual aspect of the outdoor unit if your building is listed or located in a heritage protection zone.

Local rules may impose minimum distances from property boundaries, especially for air-to-water heat pumps due to potential noise issues. It is recommended to consult municipal services to check if a permit process is required.

Compliance with the 2024–2027 energy planning is a priority in Sierre; therefore, any installation must align with the decarbonization goals of the municipal action plan to avoid administrative blocks.

Valais actively supports the transition to renewable energy. You can apply for flat-rate contributions per kW or per installation through the Building Program, which combines federal and cantonal aid. These grants are essential for reducing the total cost of your project.

The golden rule is to submit your subsidy application mandatorily before the start of the work. Any application submitted after the work has begun will be systematically rejected.

Consult the Building Program website for specific details on eligible technologies. In addition to this direct aid, remember that investments aimed at saving energy can be deducted from your tax return, according to the current cantonal provisions. It is advisable to keep all payment vouchers and detailed invoices.

Also, remember to check with the municipality of Sierre for any additional local incentives, within the framework of the 2024–2027 energy policy program, to strengthen the financial support for your thermal transition.

The flow of a heat pump project follows several structured stages. It all starts with a thorough technical assessment of your home, including an energy needs study. Once validated, you proceed to apply for municipal permits and then for subsidies.

It is imperative to wait for the written confirmation of subsidies before signing the final quotes. Electrical and hydraulic connection works are then planned.

The actual construction phase involves dismantling the old system, installing the outdoor unit, connecting to the existing distribution network, and commissioning.

Although there is no mandatory season, it is often wise to avoid winter cold peaks in Sierre, where the 72 annual frost days could complicate the switch between the old and new systems if the home is occupied.

Early planning allows for adjusting the pump during moderate temperatures, ensuring optimal thermal comfort as soon as winter conditions harden.

Avoid the classic mistake of not checking for connection to the district heating network before choosing an individual solution. Also, ensure you do not underestimate your house's insulation, as a heat pump does not replace an efficient thermal renovation.

Never sign a contract before receiving official approval for your financial aid. Finally, do not overlook the acoustic study for the location of the outdoor unit, to avoid unnecessary neighborhood conflicts.

Checklist before requesting quotes : check if the neighborhood is eligible for the CAD Sierre district heating connection; have a complete thermal calculation carried out by a specialist; examine the state of the internal heating distribution network; verify that the winter design temperature of -10 °C has been taken into account; ensure the location of the outdoor unit complies with distance and noise standards; list accessible cantonal and federal aid; request several detailed comparative quotes including commissioning and maintenance.