Installation of a new domestic hot water (DHW) production system

Changing your domestic hot water system

The use of domestic hot water varies from company to company. In some cases, it is used for sanitary installations and cooking, while in others, hot water is used for manufacturing or to assist in the production of materials or services. As a result, it is important to put in place the right solution, tailored to the specific situation.

Below is an approach that shows the stages and benefits of changing your domestic hot water (DHW) production system.

Definition of requirements for the domestic hot water system

Analysis of the current situation

• Determine the parameters of the installation, e.g. age, general condition, temperature level, consumption, and associated costs, etc.

• Define current domestic hot water consumption. The following elements provide a reliable assessment of the situation:
  • meter readings
  • monthly drinking water bill
  • consumer inventory (flow rate, temperature, schedule, etc.)

Identifying the domestic hot water system best suited to requirements

Decentralised or centralised system

• If consumption is low, check whether using cold water is not sufficient or encourage the installation of electric water heaters – e.g. for hand-washing facilities in an office building.
• Where consumption is high, a centralised solution is preferable. In this case, you need to define the power of the system (flow rate, temperature, schedule, etc.)

Definition of the solution

• Based on the requirements analysis, the solution is defined in collaboration with a qualified professional (heating installer) or a consulting engineering office.
• Take account of the existing heating system.
• It is important not to overlook the potential energy savings that can be made by recovering waste heat and combining the main heat production unit with solar thermal collectors.
• See the “Installation of a new heat production unit” measure.

Note: a permanent circulation pump must be incorporated into sanitary networks above a certain size.

Verification of the project with regard to operating permits

• When adapting existing facilities, and particularly when setting up new facilities, check the nomenclature for classified establishments.

Drafting specifications and requests for tenders

Subsidy application

Government subsidies

Temporary environmental impact aid

Extended “SME Packages Sustainability” aid scheme, to give companies greater incentives to invest in measures that significantly improve their environmental impact. Investments under this climate protection measure amount to 70 % for small businesses, 60 % for medium-sized businesses and 50 % for large businesses for projects costing more than €7 500, with a maximum aid amount of €100 000.

• Verification of company eligibility and costs: Ministry of the Economy (Department for Support to SMEs)
• Application deadline: 30 June 2025
• For questions:
  • Chamber of Commerce
  • Chambre des Métiers (Chamber of Skilled Trades and Crafts)

Fit 4 Sustainability” programme

• The “Fit 4 Sustainability” programme provides co-financing for an environmental audit and action plan on one or more topics chosen by the company (energy, greenhouse gases, waste, water, etc.)
• Subsidies of up to 50 %, 60 % and 70 % of the fees for carrying out an environmental study (energy audit and/or carbon footprint) + detailed, costed action plan to reduce consumption/GHGs (greenhouse gases) (medium- and long-term investment, ROI, etc.) – open to SMEs and large companies (except those required to carry out a statutory audit)
• Any questions? Luxinnovation

SME Packages – Sustainability

• Flat-rate aid of €5,000 for small and medium-sized businesses for projects to reduce their environmental impact, costing between €6,650 and €25,000 excluding VAT
• Any questions?
  • Chambre des Métiers for craftsmen (Chamber of Skilled Trades and Crafts)
  • Chamber of Commerce for companies in the non-craft sectors

Environmental protection scheme – Investment aid for the protection of the environment

• Verification of company eligibility and costs: General Directorate for Industry, new Technology and Research
• Assistance with the drafting of the aid application file prior to submission to the Ministry of the Economy
• Any questions? Luxinnovation
• More information and recommendations for companies on investing in the environment are available in the Guide simplifié pour les entreprises (Simplified Guide for Companies)

SME aid scheme – Aid for miscellaneous investments

Subsidies for small and medium-sized businesses , up to 10 % or 20 % of the amount of miscellaneous investments aimed at promoting the modernisation and competitiveness of the Luxembourg economy.

• Verification of company eligibility and costs: Ministry of the Economy (Department for Support to SMEs)
• Any questions?
  • House of Entrepreneurship of the Chamber of Commerce
  • Chambre des Métiers (Chamber of Trade)

N.B. State subsidies cannot be combined for the same project.

Application for subsidies from electricity and natural gas suppliers

Since 2015, natural gas and electricity suppliers have been required to make energy savings for consumers under the obligation scheme. Since then, energy suppliers have been offering support and advice, as well as subsidy programmes for consumers to implement energy efficiency measures.

The following suppliers offer this service for companies:

• Enoprimes Enovos + SUDenergie
• SUDenergie
• Sudstroum

N.B. Energy supplier subsidies can be combined with any state subsidy for the same project.

After completion of the works

If the heat production unit is changed, the installation must be inspected by an official from the Chambre des Métiers

Inspection of all new heating installations running on diesel, solid fuel or gas by the Department for the Inspection and Approval of Buildings (SCRB) of the Chambre des Métiers.

Planning maintenance and periodic inspection of the installation