Central vs. Decentralized Ventilation: Which Is Better?
Are you planning a ventilation system with heat recovery and wondering whether to choose a central or decentralized system? Both systems reliably provide fresh air, remove moisture, and recover most of the heat from the exhaust air. Nevertheless, they differ significantly in terms of installation effort, costs, and comfort – and these differences determine which system is right for your building.
The decision primarily depends on the building type, budget, and scope of renovation: what is easily feasible in new construction can quickly turn into a major construction site in an occupied old building. This comparison shows you the costs, efficiencies, and funding opportunities for both systems – as a clear decision-making aid for new construction and renovation.
Central vs. Decentralized Ventilation: The Difference
With a central controlled residential ventilation (CRV) system, a single ventilation unit handles the supply and exhaust ventilation for the entire building. The unit is typically located in the utility room, basement, or attic and is connected to all rooms via a duct network. Fresh supply air flows into living rooms and bedrooms, while stale exhaust air is extracted from the kitchen, bathroom, and toilet. Inside the unit, a heat exchanger transfers the energy from the warm exhaust air to the cold fresh air – without the air streams mixing.
Decentralized ventilation completely eliminates the need for a duct network. Instead, each room to be ventilated has its own compact ventilation unit installed directly in the outer wall. Many decentralized units operate in alternating mode: they exhaust air outdoors for a period, charging a heat accumulator, then reverse direction, and the incoming fresh air picks up the stored heat. Usually, two units operate in pairs in opposing directions to ensure balanced air exchange in the building.
The most important features of both systems at a glance:
Central CRV
- One ventilation unit serves all rooms
- Air distribution via ventilation ducts
- Heat recovery 80–95%
- Examples: Nilan Compact P, S&P CAD-HE
- Standard in new construction
Decentralized CRV
- One fan per room
- Direct installation through the outer wall
- Heat recovery 70–90%
- Example: Blauberg Vento Expert
- Standard for renovation
Direct Comparison: Costs, Efficiency, and Maintenance
When comparing both systems, one should not only look at the purchase price. Over the entire service life, maintenance requirements, noise levels, and the quality of air filtration also play a major role. A central system incurs higher initial investments, but all the technology is concentrated in a single, easily accessible location.
Decentralized units are cheaper to buy and quicker to install, but they distribute maintenance across multiple installation sites. There is also a structural difference regarding noise: the central unit operates spatially separated from the living area, while decentralized fans are located directly in the room and can be audible there – depending on the model and ventilation level. The following table summarizes the most important criteria:
| Criterion | Central CRV | Decentralized CRV |
|---|---|---|
| Total System Investment | €5,000–€15,000 | €3,000–€8,000 |
| Heat Recovery Efficiency | 85–95% | 70–90% |
| Noise | Very quiet (away from living space) | Audible (in room) |
| Filtration | Central, all rooms | Decentralized, per room |
| Ducting | Complex | No ducts |
| Maintenance | Central, easy | Multiple devices |
| Lifespan | 20–25 years | 15–20 years |
| Suitability New Construction | Standard | Possible |
| Suitability Old Building Renovation | Complex | Optimal |
For the central variant, ducting is necessary – appropriate ventilation pipes and fittings are therefore part of the planning. Filtration in central systems is handled by the central unit; suitable air filters for ventilation systems ensure permanently clean supply air – an advantage especially for allergy sufferers, as pollen and dust are captured before entering the living space.
Advantages and Disadvantages of Both Systems
No system is inherently "better" – each has its typical strengths and weaknesses, which weigh differently depending on the living situation. Central CRV primarily demonstrates its advantages when construction or extensive renovation is already underway: the ducts disappear invisibly into ceilings and walls, the technology operates practically unnoticed in the background, and maintenance is limited to a single service point.
Decentralized ventilation, on the other hand, is the pragmatic solution for existing buildings. A core drilling through the outer wall, power connection, done – without torn-up ceilings and weeks of construction work. However, you must accept that the devices are visible and audible in the room and that multiple individual devices also mean multiple maintenance points. Carefully weigh the following points against each other:
Advantages of Centralized Ventilation
- Highest heat recovery efficiency
- One service point for maintenance
- Very quiet operation
- High-quality filtration possible
- Control from one location
Disadvantages of Centralized Ventilation
- Duct installation is complex
- Often only feasible with renovation in old buildings
- Higher investment
- In case of a defect, the entire system fails
Advantages of Decentralized Ventilation
- Easy installation without tearing open walls
- Individually adjustable per room
- If defective, only one room is affected
- Lower investment
- Also possible in rented apartments
Disadvantages of Decentralized Ventilation
- Multiple devices mean more maintenance
- Sound dampening needed in the room
- Slightly lower efficiency
- Visually visible in the room
Pro Tip: Always plan a central CRV for new constructions. The ducts can be easily integrated during the shell construction – retrofitting becomes expensive.
Recommendation by Application Case
The system choice can in most cases be reduced to a simple basic rule: where construction or core renovation is already underway, central CRV is worthwhile – where the existing structure should remain as untouched as possible, the decentralized solution has the advantage. In between, there are special cases such as individual windowless bathrooms or commercial applications that deserve separate consideration.
Building size also plays a role: in multi-family homes, either each residential unit can have its own central unit, or a common central system can serve all units. For commercial properties with high air volumes and special hygiene requirements, a professional design is indispensable anyway. The following overview classifies typical situations:
| Situation | Recommendation |
|---|---|
| New single-family home | Central CRV (Nilan Compact P) |
| New multi-family home | Central CRV per residential unit or central house system |
| Old building renovation with insulation | Central CRV (renovation packages) |
| Old building without renovation | Decentralized CRV (Blauberg Vento Expert) |
| Single windowless bathroom | Bathroom fan with heat recovery |
| Clinic / large kitchen / commercial | Central CRV with professional design |
For a single windowless bathroom, you will find all details in the guide Ventilating a Bathroom Without Windows. Our article on CRV Planning with Heat Recovery explains how to correctly design a complete comfort ventilation system.
Central units from our range
- Nilan Compact P (single-family homes up to 200 m²)
- Nilan Combi 302/400 (with active heat pump)
- Nilan VPM 1200/1500 (multi-family homes)
- S&P CAD-HE (standard ventilation)
- S&P CAIT (premium commercial)
Decentralized units from our range
- Blauberg Vento Expert (with heat recovery)
- Blauberg Quattro 150 (premium)
- S&P SILENT series (standard)
- S&P TD series (inline fans)
All central units can be found bundled in the Ventilation Systems category.
Funding 2026 for Ventilation Systems
The good news for those still undecided: the state subsidizes both systems. Ventilation systems with heat recovery are considered an efficiency measure for the building envelope and are therefore eligible for subsidies via the Federal Funding for Efficient Buildings (BEG) – regardless of whether you choose the central or decentralized variant.
It becomes particularly interesting if the ventilation also heats: combined units with an active heat pump are treated as heat pumps for funding purposes and thus achieve the highest subsidy rates. If you are planning to purchase, you should definitely apply for funding before commissioning – the subsidy cannot be secured retroactively.
- Up to 70% maximum BEG funding
- Both systems are eligible for funding
- 20% Bonus for CRV heating
Both systems are eligible for subsidies through BEG funding. With central CRV with an active heat pump (Nilan Compact P), up to 70% is even possible. All details can be found in the guide to Heat Pump Funding 2026.
Frequently Asked Questions about Central and Decentralized Ventilation
Which ventilation is better?
For new construction, central CRV (efficiency, comfort). For old building renovation, decentralized CRV (easier installation).
Can I combine both?
Yes – for example, central CRV for living areas plus a decentralized bathroom fan with heat recovery. However, this is rarely done because a well-planned central system usually also covers the bathroom.
How long does the installation take?
Central CRV: 1–3 days complete. Decentralized: 2–3 hours per fan.
What applies in a rented apartment?
Decentralized CRV is simpler (smaller bore). Ask the landlord for approval – preferably in writing before hiring a craftsman.
How are heat pumps and ventilation funded?
The Nilan Compact P (ventilation with active heat pump) counts entirely as a heat pump – up to 70% funding.
Conclusion
In new construction, central CRV is the first choice thanks to its highest efficiency and quiet operation – the ducts can be integrated into the shell construction without additional effort, and the finished system works inconspicuously in the background for decades. In renovation, decentralized ventilation scores with easy installation without ducts: it brings controlled fresh air and heat recovery even where a central system is not structurally feasible. Both systems are eligible for BEG funding, so the investment in many cases turns out to be significantly cheaper than expected. If you are unsure, you should base your decision on the building condition, budget, and planned scope of renovation – and consult a specialist planner if necessary.
You can find suitable central and decentralized units in the ventilation range of wohnungstechnik.de.
