The new IEA HPT Annex “Placement Impact on Heat Pump Acoustics” has been set up as a follow up to the recently finalized IEA HPT Annex 51 “Acoustic Signatures of Heat Pumps” conducted by Austria, Denmark, Germany, France, Italy, and Sweden.

The acoustic groundwork has been laid and the basics have been successfully covered by the IEA HPT Annex 51 project, which was finished in December 2021, and its deliverables, executive summary and documents guide as well as its umbrella report submitted for review and approved by the IEA HPT ExCo in October 2021.

 The results have made their way into the development of standards. In the framework of IEA HPT Annex 51 psychoacoustics effects of heat pump acoustics have been studied with tests performed in Sweden and Austria. The acoustic effects of heat pump placement and the dependence on the operating conditions were reported. Guidelines for installers have been developed and made available.

Barriers due to unwanted noise immissions (acoustic market barriers), however, still remain and hinder the necessary growth of the heat pump market. In the course of finalizing IEA HPT Annex 51 and following recent industry requests and demands, special fields of interest emerged, which need international experience and collaboration to be treated effectively.

The proposed Annex 63 enriches independent information and expertise on the benefits of heat pumping technologies by focussing on the field of acoustics. Noise emissions are a potential threat to further spreading of heat pumps in the years to come. Thus, working on the acceptance of heat pumps by minimizing these adverse environmental impacts while keeping high energy efficiency is of great importance and in line with the Heat Pump Technologies (HPT) Technology Collaboration Programs (TCP) vision of the International Energy Agency (IEA).

Specifically, Annex 63 includes contributions to the strategic goals of HPT TCP by:

(1) Maintaining and increasing emphasis in heat pump technologies by removing adverse impacts and resolving market barriers while keeping high energy efficiency.

(2) Generating information on acoustics of heat pumps and disseminating them to all stakeholders involved including working on input for standards.

(3) Stimulating international collaboration on acoustic emissions, immissions, and perception.



Annex 63 is primarily focused on the “Placement Impact on Heat Pump Acoustics” but leaves room for special topics of heat pump acoustics covering selected applications and the refinement of methods.

The main objective from IEA HPT Annex 51 Further – removing acoustic market barriers to establish heat pumps as the number 1 choice as renewable energy and energy efficiency option for HVAC applications remians. Intense discussions, however, emphasized that avoiding show-stoppers to the rapidly growing deployment of heat pumps is gaining significance. Therefore, consumer boards will be screened to identify the challenges in the field. Furthermore, as the cooling capability of heat pumps gets more and more important, Annex 63 will include the acoustics of heat pumps in cooling modes in its focus.

Revision of cases of complaints showed, that each placement situation is unique and several aspects contribute to successful installation. Therefore, as a proper installation is key to low acoustic impact on the environment, the existing guides will be revised and linked to the developed placement tools.

Thus, the follow up to and continuation of Annex 51 “Acoustic Signatures of Heat Pumps” will work on:
• Building Acoustics Impact of Heat Pumps
• Urban Acoustics Impact of Heat Pumps
• Psychoacoustics of Heat Pumps
• Digitally Assisted Heat Pump Placement
• Dissemination

Working on common measurements and data has proven to be a fostering interaction of the partners within Annex 51 and thus, a similar interaction is being set up. For this, several opportunities arise in the described tasks.

Components have been addressed in Annex 51 – manufacturers are working intensively on improving the acoustic performance as e.g., recently shown in presentations at the Heat Pump Summit 2021 in Nuremberg (26.10.2021). Therefore, no work on acoustics of heat pump components will be pursued in this Annex.

Contact Person

Mr. Christoph Reichl,

Participating Countries

Austria, Germany


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