ErP 2026 fan compliance calculator
Check any fan against Regulation (EU) 2024/1834, which applies from 24 July 2026 and replaces ErP 327/2011. Enter the duty point at best efficiency and you get the measured efficiency, the required minimum, the N grade that was applied and a straight pass or fail — using the formulas from Annex II and Annex III.
What ErP 2026 actually requires
Regulation (EU) 2024/1834 replaced the twelve-year-old Regulation 327/2011 on 24 July 2026. It covers fans driven by motors with an electric input power between 125 W and 500 kW, measured at the best efficiency point, and it now includes jet fans, which the old regulation did not address at all.
The structure will look familiar to anyone who worked with 327/2011: you compare a measured wire-to-air efficiency against a minimum that depends on the input power and on an efficiency grade N assigned to your fan category. What changed is the steepness of the curve, the level of N, and the way categories are drawn.
The efficiency you measure
Annex III defines the efficiency as air power divided by electric input power, adjusted by three correction factors:
η = Cp · Cc · Cguard · Pu / Pe
Pu = qv · Δp air power, W (qv in m³/s, Δp in Pa)
Pe electric input power at BEP, W
Pe is taken at the motor terminals, or at the variable speed drive terminals when a VSD is part of the fan being assessed. Whether Δp is a static or a total pressure follows from the measurement category: A and C are static, B and D are total.
The minimum you have to reach
For all fans other than jet and cross flow types, Annex II point 1.1 gives the minimum as a percentage, with Pe expressed in kilowatts:
Pe < 10 kW ηmin = 4.56 · ln(Pe) − 10.5 + N [%]
Pe ≥ 10 kW ηmin = 1.10 · ln(Pe) − 2.6 + N [%]
The two branches meet exactly at 10 kW, where ηmin equals N. Cross flow fans sit outside this scheme entirely and simply have to reach 21 % total efficiency over the whole power range.
Efficiency grades — Annex II, Table 1
| Fan type | Measurement category | Efficiency | N |
|---|---|---|---|
| Axial | A, C | static | 50 |
| Axial | B, D | total | 64 |
| Forward curved < 5 kW and backward inclined centrifugal | A, C | static | 52 |
| Forward curved < 5 kW and backward inclined centrifugal | B, D | total | 57 |
| Other centrifugal fans | A, C | static | 64 |
| Other centrifugal fans | B, D | total | 67 |
| Mixed flow | A, C | static | 57 + 7(α − 45)/25 |
| Mixed flow | B, D | total | 67 |
| Jet fans ≥ 750 W | E | thrust | 50 |
Three optional characteristics reduce the grade rather than the requirement itself: a dual use fan multiplies N by 0.9, a reversible fan by 0.85, and a low noise fan by 0.9. The low noise factor is only available to axial fans of 10 kW and above with a characteristic noise value of 32 dB(A) or less at BEP.
The housing distinction is gone. Under 327/2011, backward curved centrifugal fans had separate grades with and without a housing. Regulation 2024/1834 drops that split completely — a backward curved impeller is judged the same way whether or not it comes in a scroll.
How much harder is it than 327/2011?
The single biggest structural change is that the steep curve — the one that used to apply only to backward curved centrifugal and mixed flow fans — now applies to every fan type. Axial and forward curved fans move off the shallow 2.74 / 0.78 curve onto the 4.56 / 1.10 curve and get a higher N. Because the curve is steeper, the penalty grows with power.
| Axial fan, category A/C, static | 327/2011 (N = 40) | 2024/1834 (N = 50) | Difference |
|---|---|---|---|
| 0.125 kW | 27.97 % | 30.02 % | +2.1 pp |
| 1 kW | 33.67 % | 39.50 % | +5.8 pp |
| 5 kW | 38.08 % | 46.84 % | +8.8 pp |
| 10 kW | 39.98 % | 50.00 % | +10.0 pp |
| 100 kW | 41.71 % | 52.47 % | +10.8 pp |
| 500 kW | 42.97 % | 54.24 % | +11.3 pp |
At 10 kW that is a 20 % reduction in permitted input power for the same air power. The harshest case is the forward curved centrifugal fan: below 5 kW it sits at N = 52 static, but from 5 kW upwards it falls into "other centrifugal fans" at N = 64. At 10 kW the static requirement therefore jumps from roughly 44 % to 64 % — a 31 % cut in permitted input power, which effectively legislates large forward curved fans out of the EU market.
Backward curved and EC products get off lightly. Their formula is unchanged and N moves from 64 to 67, a clean three percentage points at every power.
Beyond efficiency: information, part load and spare parts
Passing the efficiency threshold is only part of the obligation. From 24 July 2026 you must publish a defined information set — efficiency and grade at BEP, measurement and efficiency category, whether a VSD is integrated, specific ratio, inherent speed, disassembly and recycling guidance, and more — in the technical documentation, on or near the rating plate, and on a free-access website kept live for 20 years after the last unit of the model is placed on the market.
From 24 July 2027, part-load information is added. Standard fans need at least three performance curves: one at the inherent speed, one at 40–50 % of it, and one roughly midway between them, each reporting volume flow, pressure, electric power, speed and efficiency. From 24 July 2028, spare parts — impellers, stator elements, drives, bearings, sensors, wearing parts, motors below 10 kW — must be available to professional repairers for ten years after the last unit is placed on the market.
For a manufacturer with a few hundred catalogue items, the information and part-load obligations are a bigger job than the efficiency threshold itself. That is exactly what a selection program is for: the curves, the declared values and the free-access product page are generated from one dataset instead of maintained by hand. See how CloudAir handles it →
Frequently asked questions
Is there a second, stricter tier later on?
No. Unlike 327/2011, which stepped up in 2013 and again in 2015, Regulation 2024/1834 sets a single efficiency level. What is staggered is the type of requirement — efficiency and product information in 2026, part load in 2027, spare parts in 2028 — not the stringency. A review is scheduled for July 2030.
What about fans already built into other products?
Fans integrated into other products had a transitional period: the Annexes of 327/2011 continued to apply to them until 24 July 2027. There is also a long derogation for replacement fans — a 327/2011-compliant fan may still be sold until 2037 as a replacement for a fan placed on the market before 24 July 2026, provided no compliant fan fits, and provided it carries the prescribed warning statement on the packaging, data sheet and online listing.
My fan has a variable speed drive. Does that help?
If the VSD is included in the conformity assessment, a correction factor Cc applies — 1.04 for fans of 5 kW and above, and a power-dependent value below that. Tick the VSD box in the calculator to include it. Note that the rating plate must then carry the statement that a variable speed drive is integrated within the fan.
Why does the calculator ask for the speed?
Annex II point 1.7 gives a separate, more lenient requirement for centrifugal fans with a specific speed σ below 0.12, below 10 kW, in measurement category B or D on a total pressure basis. Supplying the speed at BEP lets the calculator work out σ and apply that branch when it is relevant.