EU ERP Ecodesign Lot 6: Heat Recovery Requirements for Residential Ventilation
The European Union’s Ecodesign Regulation (EU) No 1253/2014 — commonly referred to as Lot 6 for ventilation units — sets mandatory energy-performance requirements for residential and non-residential ventilation units placed on the European market. For specifiers of air-to-air heat exchangers, Lot 6 is the single most important compliance threshold because it directly governs whether a recuperator may be sold at all, and at what efficiency.
What Lot 6 covers
Lot 6 applies to ventilation units with a flow rate up to 2,000 m³/h, including both residential units and smaller commercial units. It defines two equipment classes:
- Class A (residential) — units intended for dwellings.
- Class B (non-residential) — units for other buildings within the flow limit.
For units with heat recovery, the regulation sets a minimum thermal efficiency of the heat exchanger and a maximum specific power input (electrical energy per unit of air moved).
Minimum heat recovery efficiency
For residential ventilation units with heat recovery, Lot 6 requires a thermal efficiency of at least 73% (measured according to EN 308 / EN 13141-7). For non-residential units the threshold is at least 68%. These are not aspirational targets — they are the legal floor. A plate or rotary recuperator that cannot demonstrate the required effectiveness on a certified test cannot carry the CE mark for the EU market.
| Parameter | Residential (Class A) | Non-residential (Class B) |
|---|---|---|
| Max airflow covered | ≤ 2,000 m³/h | ≤ 2,000 m³/h |
| Min. heat recovery efficiency | 73% | 68% |
| Max. specific power input | 0.45 Wh/m³ | 0.85 Wh/m³ |
| Bypass requirement | Required for free cooling | Required for free cooling |
Why the efficiency floor matters for specifiers
Before Lot 6, the European market was flooded with low-cost ventilation units whose “heat recovery” recuperators delivered 40–50% effectiveness — barely better than an open window. The 73% floor forced a generational upgrade: aluminium and polymer plate cores, and enthalpy wheels, had to be engineered to a real performance bar. For an OEM or importer, this means the recuperator is now a designed component, not an afterthought.
Interaction with EPBD and energy labels
Lot 6 sits inside the broader EU framework: the Energy Performance of Buildings Directive (EPBD) requires nearly-zero-energy buildings, and ventilation heat recovery is a primary lever. A unit that meets Lot 6 also tends to score well on the EU energy label for ventilation, which ranges from A+ to G. Specifiers chasing EPBD compliance should treat the Lot 6 percentages as the starting point, not the goal.
Practical compliance checklist
1. Confirm the unit is tested to EN 308 (or EN 13141-7 for residential) by an accredited lab.
2. Verify the reported efficiency is the sensible effectiveness at the declared reference conditions, not a best-case marketing number.
3. Check the specific power input — a high-efficiency core with a greedy fan fails Lot 6.
4. Ensure a bypass is present for summer free cooling.
5. Keep the Declaration of Conformity and test report on file for market surveillance.
Bottom line
ERP Ecodesign Lot 6 turned heat recovery from an optional extra into a regulated performance feature. For any residential or small commercial ventilation unit sold in the EU, a certified plate or wheel recuperator at ≥73% (residential) / ≥68% (non-residential) sensible effectiveness, with a low specific fan power and a bypass, is the baseline. Specifying below it is simply not an option in the European market.