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Heat pumps · 144 models

Quietest 4–6 kW heat pumps

144 models in our database meet this; below the first 25 in order.

Criteria:

  • Rated output 35 °C from 4 up to 6 kW
  • Sorted by: Outdoor unit sound power (lowest first)

Only models for which these figures are known. This is a ranking by data, not a test or recommendation; the source of every value is on the product page.

# Model1,2 Outdoor unit sound power Rated output 35 °CSCOP (35 °C)Refrigerant
1 STIEBEL ELTRON WPL 09 ICS classic 32 dB(A) 4.8 kW4.53R410A
2 STIEBEL ELTRON WPL 09 IKCS classic 32 dB(A) 4.7 kW4.46R410A
3 Tecalor TTL 4.5 ICS 32 dB(A) 4.8 kW4.53R410A
4 Tecalor TTL 4.5 IKCS 32 dB(A) 4.7 kW4.46R410A
5 Bosch CS7000iAW 7 IRB-S 36 dB(A) 5.18 kW4.68R410A
6 Bosch CS7000iAW 7 IRMB-S 36 dB(A) 5.17 kW4.41R410A
7 Buderus Logatherm WLW196i-6 IRB 36 dB(A) 5.18 kW4.68R410A
8 Buderus Logatherm WLW196i-6 IRTP120 36 dB(A) 5.17 kW4.41R410A
9 Bosch Compress CS5800iAW 4 ORE-S (AW 4 OR-S + CS5800iAW 12 E) 40 dB(A) 4.4 kW4.58R290
10 Bosch Compress CS5800iAW 4 ORM-S (AW 4 OR-S + CS5800iAW 12 M) 40 dB(A) 4.4 kW4.55R290
11 Bosch Compress CS5800iAW 4 ORMB-S (AW 4 OR-S + CS5800iAW 12 MB) 40 dB(A) 4.4 kW4.55R290
12 Bosch Compress CS6800iAW 4 ORE-S (AW 4 OR-S + CS6800iAW 12 E) 40 dB(A) 4.4 kW4.58R290
13 Bosch Compress CS6800iAW 4 ORM-S (AW 4 OR-S + CS6800iAW 12 M) 40 dB(A) 4.4 kW4.55R290
14 Bosch Compress CS6800iAW 4 ORMB-S (AW 4 OR-S + CS6800iAW 12 MB) 40 dB(A) 4.4 kW4.55R290
15 Bosch CS5800iAW 4 OR210 MP-S 40 dB(A) 4.4 kW4.14R290
16 Bosch CS5800iAW 4 ORE-S 40 dB(A) 4.4 kW4.58R290
17 Bosch CS5800iAW 4 ORM-S 40 dB(A) 4.4 kW4.55R290
18 Bosch CS5800iAW 4 ORMB-S 40 dB(A) 4.4 kW4.55R290
19 Bosch CSH5800iAW 4 40 dB(A) 4.4 kW4.34R290
20 Buderus HC HYC20 IT-4 40 dB(A) 4.4 kW4.34R290
21 Buderus Logaplus M WLW176i-4 AR E (Logatherm WLW-4 MB AR + WLW176i-12 E) 40 dB(A) 4.4 kW4.58R290
22 Buderus Logaplus M WLW176i-4 AR TP70 (Logatherm WLW-4 MB AR + WLW176i-12 TP70) 40 dB(A) 4.4 kW4.55R290
23 Buderus Logaplus M WLW186i-4 AR T180 (W) (Logatherm WLW-4 MB AR + WLW186i-12 T180 (W)) 40 dB(A) 4.4 kW4.55R290
24 Buderus Logatherm WLW176i-4 AR E 40 dB(A) 4.4 kW4.58R290
25 Buderus Logatherm WLW176i-4 AR T180 40 dB(A) 4.4 kW4.55R290

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Sources

  1. List of eligible heat pumps (BEG) — Bundesamt für Wirtschaft und Ausfuhrkontrolle (BAFA) · accessed 29 Sept 2026
  2. Heat Pump Keymark certificates — EHPA / DIN CERTCO (Heat Pump KEYMARK) · accessed 29 Sept 2026