Zero CO2 airconditioning

Cutting down on fossile energy consumption is a top priority for our generation. Climate control in buildings is one of the biggest factors in energy demand. SoundEnergy introduces a breakthrough technology that brings a fundamental change in this respect: cooling and heating buildings without using electricity or gas.

The basis of the concept can be summarized as follows:

  • One machine: the THEAC-25
  • Two applications: solar heat or waste heat
  • Double output: cooling and heating

The innovation is a result of 20 years of research into Thermo Acoustics conducted by Kees de Blok, SoundEnergy’s R&D manager. He succeeded to control Thermo Acoustics in such a way, that it can convert heat into cold. The result is the THEAC-25; a tried & tested machine producing 25kW cooling power.

The technology is completely clean (zero CO2 and zero GWP) and sustainable as well as economically attractive. Using the technology saves costs.

The advantages of the THEAC‑25

  • No use of electricity producing coldness
  • No use of gas producing warmth (secondary function)
  • Zero CO2
  • Zero global warming potential (GWP=0)
  • Advanced, non-mechanical technology
  • Low level of noise production
  • Technical life-cycle up to 30 years
  • No maintenance costs
  • Economically attractive

One machine

The Thermo Acoustic Energy Converter, THEAC-25, developed by SoundEnergy will function as a central unit in the installation concept for climate control. It’s core function is converting heat into cold by using thermo acoustic technology. Feeding heat input into one side of the THEAC-25 results into cold output at the other side, enabling the production of cold water or cold air. The output of the THEAC-25 can reach temparatures below −30°C.

The THEAC-25 is sophisticated technology, not using any mechanical process, chemicals or precious metals. Traditional ariconditioning systems use chemical fluids that are highly damaging to the environment. The global warming potential of these refrigerants is rated 2.000 (GWP=2.000).

The working fluid in the THEAC-25 is Argon, which is an inert gas. It is easily available: about 0.94% of our atmosphere consists of Argon. And more important: Argon has zero global warming potential (GWP=0).

The pressure inside the THEAC-25 is 10 bar. This is comparable to gascylinders and LPG-tanks in cars. Therefore, the construction of the THEAC-25 complies to the Pressure Equipment Directive (PED).

Being zero GWP and zero CO2, the THEAC-25 is by far the most clean and sustainable technology available for climate control.


SoundEnergy has gained recognition and support of three leading innovation funds:

  • Tech For Future (NL)
    Focus: series-production, climate control
  • KIC InnoEnergy Highway Program (EUR)
    Focus: business creation
  • Kennispark Twente TOP Light (NL)
    Focus: start-up support

Two applications

The core function of the THEAC-25 is converting heat into cold. This means that any installation system with the THEAC-25 requires a source of heat. There are two sustainable options: one is to use solar heat, the other is to use waste heat.

Solar heat

Heat from the sun is collected by VTC-panels (vacuum tube solar collectors). These panels can heat-up water up to 160°C in summer. The hot water is converted to cold by the THEAC-25. The low temparatures are used to produce cold water or cold air that can be distributed in the building.

Waste heat

Another option is the use of waste heat. By inserting an additional heat exchanger in, for example, a flue gas exhaust the harvested heat can be channelled into the THEAC-25 to convert it into cold. The source of input is different, but the concept and result is identical.

Depending on the demands for climate control, especially the availability criteria, provisions can be made to either store overproduction of cold or arrange back-up heat supply.

THEAC-25 images

Solar application

  1. VTC-Panels
    Hot water 40–160 °C
  2. Dry-coolers
  3. THEAC-25
    220 x 220 x 60 cm 480 kg
    25kW cooling power

Waste heat application

  1. Heat exchanger
  2. Dry-coolers
  3. THEAC-25
    220 x 220 x 60 cm 480 kg
    25kW cooling power

Double result

The heat source for the THEAC-25 is not only useful to produce cold. It can also be used to feed the heating system. During a big part of autumn and winter, the hot water from the VTC-panels still reaches temperatures over 40°C. This heat can be fed directly into the heating system of the building. The result is a full use of the gained heat throughout the year.

For waste heat, this secondary use needs no explanation.

The big advantage of an installation concept based on the THEAC-25, is that there is one, integrated system for heating and cooling.

Contributing to the heating system can be seen as a secondary function of the THEAC-25 concept, but it’s impact in reducing gas consumption can be significant. By using storage buffers, in many cases it can supply enough energy to take the building of completely off the gas grid and create a situation of a 100% zero CO2 climate control.

How the THEAC-25 can best be applied in climate control, what the possibilities and limitations are, depends on the specific nature and demands regarding the building. It will always require the involvement of installation experts who are in charge of the overall climate control concept.

Cost saving

The THEAC-25 is a highly competitive technology. Compared to traditional airconditioning, the yearly costs and the total costs of ownership are significantly lower. If the heating capacity enables cutting out gas consumption completely, the financial advantages are even higher.

If you have a concrete project and seriously consider to use the THEAC-25, you can use the ‘I am interested’ form.

It is important to mention that the THEAC-25 is not a one-to-one replacement of a heatpump in an existing system. Traditional airconditioning systems are a controlled, relatively complex system based on HFK and CFK refrigerants. These systems are not able to transport cold by water/glycol or air.