Heat recovery ventilation in Luxembourg: prices, Klimabonus grants and installation in 2026
In a well-insulated home, heat recovery ventilation (HRV / MVHR) is no longer optional — it is a technical necessity. By recovering up to 90% of the heat from extracted air, it maintains optimal indoor air quality without losing any energy. In Luxembourg in 2026, installation as part of a Klimabonus-eligible energy renovation can benefit from grants from the Environment Administration (AEV), stackable with Enoprimes and the reduced 3% VAT rate. The total installed cost ranges from €6,000 to €18,000 depending on floor area and the type of system chosen — an investment recouped in 8 to 15 years through heating bill savings.
How does heat recovery ventilation work?
An MVHR system (Mechanical Ventilation with Heat Recovery) simultaneously performs two functions that single-flow ventilation cannot combine: it extracts stale air from wet rooms (kitchen, bathroom, WC) and supplies fresh filtered air to living areas (bedrooms, living room, study), via a separate duct network.
The technical innovation lies in the heat exchanger integrated into the unit: the two air streams cross without ever mixing. The heat from the extracted air is transferred to the incoming air, pre-heating the fresh air in winter (and cooling it in summer for reversible models). Modern systems achieve a heat recovery rate of 85 to 95%, mechanically reducing the heating energy required for air renewal.
Integrated filters (minimum F7 class recommended for Luxembourg, or HEPA for allergy sufferers) trap fine particles, pollen and dust. The indoor air, continuously renewed, has CO₂ and volatile organic compound (VOC) concentrations significantly lower than those of a naturally ventilated home.
Is your home compatible? Use our simulator to estimate your grants and get an initial cost estimate for your MVHR project in Luxembourg.
Simulate my grants →Why MVHR is essential in Luxembourg
The Grand Duchy applies insulation standards among the most demanding in Europe. Luxembourg’s energy passport and the BBB (low-energy house) and AAA (passive house) standards require increasingly airtight building envelopes. The more airtight a building is, the less natural ventilation occurs through infiltration — and the more mechanical ventilation becomes indispensable.
In houses built before the 1990s, air leaks through the envelope provided minimal but uncontrolled air renewal, at the cost of significant heat losses. After external thermal insulation (ETI) or triple glazing installation, this natural renewal drops dramatically. Without MVHR, the consequences are:
Condensation and mould
Moisture produced by occupants (cooking, showering, breathing — around 10 litres of water per day for a household of 4) can no longer escape. It condenses on cold surfaces, promoting the growth of mould and fungi, which are particularly harmful to health and to the building fabric.
Accumulation of indoor pollutants
CO₂, VOCs from paints and furniture, fine particles, radon (present in certain geological zones of Luxembourg): without sufficient air renewal, these pollutants accumulate at levels harmful to quality of life and health, particularly for children and asthma sufferers.
Degradation of insulation performance
Stagnant moisture progressively degrades insulation materials. Saturated mineral wool loses a large part of its thermal properties. MVHR protects the insulated envelope by maintaining a stable relative humidity level of 40 to 60%.
Regulatory obligation during major renovation works
In Luxembourg, any renovation targeting an energy class BBB or AAA (eligible for Klimabonus grants with an energy audit) must include a high-performance mechanical ventilation solution. The accredited energy advisor systematically checks this point when drawing up the advisory report.
The Enoprimes programme (from energy suppliers Enovos/Creos) includes a specific grant for installing heat recovery ventilation in a well-insulated home. This grant is stackable with the AEV Klimabonus grants. Check your eligibility at enoprimes.lu.
Centralised vs decentralised systems: which to choose?
There are two main families of MVHR systems, with very different installation approaches. The choice depends primarily on the building’s configuration, its airtightness level and the available budget.
Centralised MVHR
This is the reference solution for new builds and major renovations. A single central unit (generally installed in the loft, boiler room or plant room) serves the entire home via a network of rigid or semi-rigid ducts. The heat exchanger is integrated into the unit, with recovery rates of 80 to 95%.
Advantages: optimal performance, centralised maintenance (a single unit to maintain), near-silent operation in living areas, intelligent management possible (CO₂ regulation, humidity detection).
Disadvantages: requires ductwork throughout the home — ideal for new builds or major renovations with loft and partition access. In an existing building without simultaneous major works, installation is more complex and costly.
Decentralised MVHR (room-by-room units)
Autonomous units (generally in pairs to ensure cross-recovery) are installed directly in the walls of each main room. They require no ductwork.
Advantages: fast and minimally invasive installation in an occupied existing home, no ductwork required, ideal for partial renovations or apartments where major works are impossible.
Disadvantages: generally lower recovery rate (60 to 80%), maintenance of multiple units, overall cost comparable to a centralised system for large areas.
| Criterion | Centralised | Decentralised |
|---|---|---|
| Heat recovery | ● 85 – 95% | ◐ 60 – 80% |
| Installation works | ◐ Ductwork required (invasive) | ● Simple wall penetrations |
| Ideal for new build or major renovation | ● Yes | ◐ Possible but sub-optimal |
| Ideal in occupied home | ✗ Complex | ● Yes |
| Noise level in living areas | ● Very quiet | ◐ Variable by unit |
| Maintenance | ● Single central unit | ◐ Multiple units |
| Klimabonus eligibility | ● Yes (in global renovation) | ● Yes (subject to conditions) |
Comparison based on manufacturer technical data and Klimabonus 2026 eligibility conditions — klima-agence.lu
A centralised MVHR system only works efficiently in a sufficiently airtight building. If your home has significant air leaks (n50 > 3 h⁻¹), a proportion of the fresh air escapes before reaching the living areas, considerably reducing system performance. A Blower Door airtightness test is essential before choosing your system.
2026 installed prices for MVHR in Luxembourg
The total cost of an MVHR system in Luxembourg includes equipment (central unit or decentralised units), filters, ductwork (for a centralised system), supply and extract grilles, commissioning and labour. The prices below are indicative and reflect the price levels charged by certified installers in the Grand Duchy in 2026.
| Configuration | Equipment only | Supplied + installed | Note |
|---|---|---|---|
| Centralised MVHR — house 80–120 m² | €4,000 – 7,000 | €6,000 – 11,000 | Renovation with loft access |
| Centralised MVHR — house 120–200 m² | €6,000 – 10,000 | €9,000 – 16,000 | More extensive ductwork |
| Centralised MVHR — house > 200 m² | €8,000 – 12,000 | €12,000 – 18,000 | Premium system possible |
| Decentralised MVHR — apartment 60–90 m² | €2,500 – 5,000 | €4,000 – 8,000 | 4 to 6 units depending on area |
| Decentralised MVHR — house 90–150 m² | €4,000 – 7,000 | €6,000 – 11,000 | 6 to 10 units depending on configuration |
Indicative price ranges — Luxembourg market 2026. Actual amounts vary depending on ductwork complexity, floor level, accessibility and chosen finishes.
The main price variation factors in Luxembourg are: floor area and number of rooms, ductwork complexity (accessible loft or not, presence of concrete slabs), central unit performance level (recovery rate, filtration, intelligent control), possible need for preparatory airtightness works, and finally installer hourly rates, which are higher in Luxembourg than in neighbouring countries.
High-efficiency heat recovery unit (95%): €7,500
Ductwork (accessible loft) + grilles: €2,800
Installation labour + commissioning: €2,200
Gross total: €12,500 incl. VAT (17%)
With reduced 3% VAT (property over 10 years old): ≈ €10,800
After estimated Klimabonus + Enoprimes grants: indicative out-of-pocket ≈ €7,000 – 9,000
Grants and subsidies for MVHR in Luxembourg in 2026
MVHR is eligible for several grant schemes in Luxembourg, depending on the renovation context. The golden rule is always the same: the agreement in principle must be obtained from the housing grants single window before works begin, otherwise the right to subsidies is forfeited.
1. Klimabonus Wunnen 2026 (Environment Administration)
Since 1 January 2026, the Klimabonus Wunnen has been reformed. The 2026 scheme is undergoing legislative procedure (publication in the Official Gazette pending) but is applicable from 1 January 2026 with retroactive effect. Heat recovery mechanical ventilation is eligible for grants in two contexts:
- Global renovation with energy audit: the MVHR system is integrated into the overall grant calculation, whose amount is determined by the final energy performance achieved (class improvement on the energy passport). This is the route that maximises total grants.
- Single-measure renovation (without energy audit): if MVHR is the only work carried out, a simplified grant can be requested. Works must be performed by an accredited company or accompanied by an energy advisor (additional grant of €400 for advisory services and €100 for offer compliance verification).
The specific flat-rate amounts for MVHR under the 2026 Klimabonus scheme had not yet been published in the Official Gazette at the time this page was last updated. For the exact amounts applicable to your project, use the official simulator at klimabonus.lu or consult a certified Klima-Agence advisor.
2. Enoprimes (Enovos / Creos)
The Enoprimes programme from Luxembourg’s electricity and gas suppliers includes a grant for installing heat recovery ventilation in a well-insulated home. This grant is stackable with the AEV Klimabonus. Applications must be submitted before signing the quote — check the exact conditions at enoprimes.lu.
3. Super-reduced 3% VAT
The 3% VAT rate (instead of 17%) applies to renovation works in properties over 10 years old (age calculated from the building permit date). Since the 2026 Klimabonus reform, this threshold was lowered from 20 to 10 years, significantly broadening access. On a €12,500 installation, the VAT saving reaches approximately €1,750.
4. Klimabonus Social Topup
Low-income households benefiting from Klimabonus Wunnen grants can apply to the Ministry of Housing for a Social Topup, which can double the base Klimabonus grant. This scheme must be applied for separately through the housing grants single window.
5. Municipal grants
Some Luxembourg municipalities offer supplementary grants for energy renovation works. Amounts generally range from €1,500 to €3,000 depending on the municipality. Contact your municipal administration or Klima-Agence directly to find out what grants are available in your area.
To maximise your grants, integrate MVHR into a global renovation project including insulation and/or heating replacement, and have an energy audit carried out by a certified Klima-Agence advisor before submitting your application. The « global renovation with energy audit » route systematically generates higher total grants than the « single measure » route.
Calculate your grants in a few minutes. Our simulator integrates Klimabonus, Enoprimes and reduced VAT to give you an estimate of your real out-of-pocket cost.
Estimate my grants →The Blower Door airtightness test: an essential prerequisite
In Luxembourg, the airtightness test (commonly called the Blower Door test) must be carried out according to DIN ISO 9972 method A. It is performed by FLIB-certified offices (Organisation for Airtightness in Construction).
This test is mandatory to obtain the grants relating to mechanical controlled ventilation in existing homes undergoing energy renovation in Luxembourg. It qualifies the building envelope’s airtightness via the n50 value (air change rate under a 50 Pa pressure difference).
| Building category | Required n50 value | MVHR |
|---|---|---|
| House with MVHR — standard | n50 < 1.5 h⁻¹ | ● Compatible centralised |
| Low-energy house (BBB) | n50 < 1.0 h⁻¹ | ● Recommended |
| Passive house (AAA) | n50 < 0.5 h⁻¹ | ● Mandatory |
| EnerPHit renovation (passive renovation) | n50 < 1.0 h⁻¹ | ● Mandatory |
n50 values per Luxembourg regulations and Klimabonus requirements — sources: 1nergie.lu, ADEFI Luxembourg
If your home does not yet meet the required n50 threshold, it is possible to carry out a pre-test during construction (before finishes), identify leaks via thermal camera and smoke, and correct them before the official measurement. This approach, recommended by Luxembourg engineering firms, avoids costly remediation work after finishes are in place.
Good airtightness also improves the result of your home’s energy passport (CPE). By integrating the actual n50 measurement into the calculation (rather than the very penalising default value), you can improve your property’s energy class by one level — which increases the property’s value and raises the amount of Klimabonus grants.
Typical installation process in Luxembourg
Installing a centralised MVHR system in an existing home follows several well-defined steps that determine grant eligibility and the final performance of the system.
Energy audit and application for agreement in principle
Before any commitment, have an energy audit carried out by a certified Klima-Agence advisor. This audit produces a report with recommendations and allows an application for agreement in principle to be submitted on MyGuichet.lu. No quote should be signed before this agreement is obtained for works eligible for the Klimabonus with energy audit.
Feasibility assessment and preliminary Blower Door test
The certified installer carries out a technical visit to assess the home’s configuration: loft accessibility, floor type, positioning of wet rooms and living areas. A Blower Door test is performed to determine the current airtightness level and identify any airtightness works required before or during installation.
Sizing and duct network design
Ventilation flow rates are calculated based on floor area, number of occupants and Luxembourg regulatory flow rates. The ductwork route is defined to minimise pressure losses while limiting impact on living space. The choice of central unit model (self-regulating, humidity-regulated, with summer bypass) is finalised at this stage.
Airtightness works (if required)
If the current n50 is too high, air leak sealing works are carried out: sealing of joinery, sealing of duct and cable penetrations, treatment of junctions between materials. These works directly determine the final MVHR performance.
Central unit and ductwork installation
The central unit is installed in the plant room, loft or boiler room. The rigid duct network (or semi-rigid for difficult access areas) is installed, with insulation on ducts passing through unheated spaces. Supply grilles (living rooms) and extract grilles (wet rooms) are fitted and adjusted.
Commissioning, balancing and final test
The installer balances flow rates room by room according to the ventilation plan. Actual flow rate measurements are taken at each grille. A final Blower Door test certifies the n50 value achieved, which is required for the Klimabonus grant application.
Application for Klimabonus grant payment
After work completion and issue of the final invoice, the payment application is submitted on MyGuichet.lu within 4 years following 31 December of the invoicing year. Grants are paid directly into your bank account after the AEV validates the application.
MVHR ducts passing through unheated spaces (cold loft, crawlspace, garage) must be thermally insulated. Overlooking this can reduce the effective heat recovery rate by 10 to 20%, making the investment less cost-effective and potentially invalidating eligibility for Klimabonus grants at the compliance check.
MVHR maintenance: what you need to know
The lifespan of a quality MVHR system is 15 to 20 years. Regular maintenance is therefore the key to preserving performance over time and avoiding premature failures.
Operations to carry out
Every 3 to 6 months: visual inspection of filters and cleaning or replacement if necessary. G4/F7 filters clog progressively depending on outdoor air quality. In Luxembourg, proximity to busy roads or agricultural areas can accelerate this clogging. A blocked filter increases fan electricity consumption and reduces flow rates — and therefore system efficiency.
Every 12 months: cleaning of the heat exchanger and condensate tray, flow rate check at each grille, ductwork airtightness check, central unit casing inspection.
Every 3 to 5 years: complete professional cleaning of the duct network, check of duct fixings and insulation, general electrical inspection.
The estimated annual cost of routine maintenance for a centralised MVHR system is between €100 and €250 per year, including replacement filters and potentially a maintenance contract. Some Luxembourg installers offer annual maintenance contracts covering filters, inspection and labour.
Set an annual reminder for your MVHR maintenance. Under Luxembourg regulations, the owner of a rented property is responsible for filter replacement and major repairs. As an owner-occupier, there is no formal legal obligation, but regular maintenance is the guarantee of preserving initial performance — and avoiding invisible electricity overconsumption.
5 mistakes to avoid for your MVHR project in Luxembourg
Starting works before the Klimabonus agreement in principle
This is the elimination error. Any project that starts — even by signing the quote in some cases — before obtaining the agreement in principle from the housing grants single window permanently loses its right to Klimabonus grants. The rule is absolute: agreement in principle first, works second.
Choosing a non-certified installer
In Luxembourg, works must be performed by an accredited company to be eligible for Klimabonus grants. An installer not registered in the Chamber of Trades register, or not certified for this type of installation, automatically invalidates the grant application. Always check your service provider’s certifications before signing the quote.
Installing MVHR in an insufficiently airtight building
An MVHR system in a building with n50 > 3 h⁻¹ will only deliver a fraction of its theoretical performance. The investment cost will be poorly recouped, energy consumption disappointing, and perceived comfort insufficient. Carry out the Blower Door test first and if necessary, combine MVHR with airtightness works.
Neglecting duct insulation
Uninsulated supply or return ducts passing through unheated spaces (cold loft, garage) create thermal losses that partially negate the exchanger’s heat recovery. Insist that the quote explicitly mentions thermal insulation of all ducts outside the heated volume.
Forgetting the summer bypass and filter maintenance
In summer, an MVHR system without a summer bypass can unnecessarily heat incoming air (the exchanger transfers heat from indoor air to the cooler outdoor air). Choose a model with automatic bypass. And once installed, make sure filters are replaced at recommended intervals — forgetting this simple operation is the leading cause of underperformance in real-world MVHR installations.
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Frequently asked questions about MVHR in Luxembourg
Can MVHR be installed in a co-ownership apartment in Luxembourg?
Yes, but the options depend on the building’s configuration. A decentralised system (room-by-room units with facade penetrations) is generally the most realistic solution, subject to co-ownership approval for facade penetrations. A centralised system is possible if the building undergoes a coordinated global renovation among co-owners. In both cases, Klimabonus grants are accessible on an individual basis for the apartment concerned.
Is MVHR noisy?
A properly sized and installed system is virtually inaudible in living areas. The noise level of supply grilles in a quality centralised MVHR system is typically below 25 dB(A) at nominal flow — well below the perception threshold in a normal living room. Decentralised systems are slightly more noticeable but remain below 30–35 dB(A) in most cases. Abnormal noise (whistling, vibration) generally indicates a balancing issue or a blocked filter.
How much can you save on your heating bill after installation?
In a well-insulated home in Luxembourg, ventilation represents a significant share of heat losses. With MVHR recovering 90% of the heat from extracted air, savings on the ventilation component can reach 15 to 25% of heating consumption. For a 150 m² heated home, this typically represents €300 to €1,200/year in savings, depending on energy tariffs and existing insulation level. These estimates are indicative and depend heavily on occupancy patterns and thermostat settings.
Does MVHR work well with a heat pump?
Yes, it is actually the optimal combination for high-performance energy renovation in Luxembourg. MVHR reduces the heating needs related to ventilation, which lowers the power required from the heat pump and improves its COP (coefficient of performance). The two systems complement each other: the heat pump covers residual heating needs and domestic hot water, while the MVHR ensures air renewal without thermal losses. This combination is at the heart of renovation projects targeting BBB or AAA class in Luxembourg.
How much does a Blower Door test cost in Luxembourg?
The price of a Blower Door test in Luxembourg varies depending on building size and the chosen firm. For a standard detached house, allow between €400 and €800 for an official test (according to DIN ISO 9972 method A), including the measurement report and leak identification. Some firms offer pre-test + final test packages. The cost of this test is eligible for grants as part of a global renovation with energy audit.
Can you install MVHR yourself to reduce costs?
Technically possible for simple decentralised systems, but inadvisable and incompatible with obtaining Klimabonus grants. In Luxembourg, grants are conditional on works being performed by an accredited company. An unprofessional installation risks failing to achieve required performance (flow rates, joint airtightness, duct insulation), invalidating equipment warranty and compromising the Blower Door test result. The immediate saving on labour is often cancelled out by the loss of grants and any remediation costs.
How to find a certified MVHR installer in Luxembourg?
Several resources are available: the list of certified Klima-Agence advisors and tradespeople at klima-agence.lu, the Luxembourg Chamber of Trades for accredited companies, and our own network of certified partners. By requesting multiple quotes through our form, you will be put in touch with installers qualified for Klimabonus installations, whose competencies and certifications have been verified.
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