Heat pumps · INT

A.O. Smith WWHB 20

The A.O. Smith WWHB 20 is a heat pump with SCOP (35 °C) 5.68 and refrigerant R134A.^1,2

Last updated: October 15, 2026Technical specifications ⇄ Compare this model

SCOP (35 °C): 5.68²
Seasonal efficiency: how much heat you get per kWh of electricity across a heating season.
Refrigerant: R134A¹
Official source
Type (source): Water-to-water¹
Official source
Rated output 35 °C: 22kW²
Official source
Rated output 55 °C: 20kW²
Official source

Technical specifications

General
Type (source)	Water-to-water¹
Performance
Rated output 35 °C	22 kW²
Rated output 55 °C	20 kW²
Efficiency
SCOP (35 °C)	5.68²
SCOP (55 °C)	4.25²
Seasonal efficiency ηs 35 °C	224 %²
Seasonal efficiency ηs 55 °C	167 %²
Energy label 35 °C	A+++²
Energy label 55 °C	A++²
Noise
Indoor unit sound power	62 dB(A)²
Refrigerant
Refrigerant	R134A¹
Refrigerant GWP	1,430¹
Grants & market
ISDE grant (NL)	6,225 €¹

How it ranks

SCOP (35 °C): better than 23% of comparable models in our database (Heat pumps · Water-to-water · ≥ 14 kW; n = 65).

Rank 51 of 66

Compared with every model on VersusIndex in the same group with a known value; equal values do not count as better. This says nothing about price, installation or reliability.

Similar models

Other brands, same type and a comparable size.

Frequently asked questions

What is the SCOP (35 °C) of the A.O. Smith WWHB 20?

The SCOP (35 °C) of the A.O. Smith WWHB 20 is 5.68.^1,2

Which refrigerant does the A.O. Smith WWHB 20 use?

The refrigerant of the A.O. Smith WWHB 20 is R134A.^1,2

Sources

ISDE heat pump notification code list — Rijksdienst voor Ondernemend Nederland (RVO) · accessed Sep 28, 2026
European Product Registry for Energy Labelling (EPREL) – heat pumps — Europese Commissie · accessed Oct 15, 2026

Key figures