Case

Retrofit pilot on an office heat pump at The Green Village

Seven months on a real installation, with installer Warmtebouw and heat pump specialist IBK: the first test of the expander on a professional heat pump.

The installation

The Green Village is the living lab on the TU Delft campus where new energy technology is tried on real buildings. For this pilot an existing office heat pump was retrofitted with our pressure exchanger — known during the project as the X-pander — in place of its expansion valve.

Two partners made the installation a professional one rather than a lab bench:

  • Warmtebouw, the installer of the existing office heat pump, carried out the retrofit and was the natural party to inspect the test set-up.
  • IBK, an industrial heat pump specialist, supported the system engineering of the device.

What was tested

This was the first time the device ran on a professional heat pump system. The questions were the ones an operator asks first:

  1. Does it integrate into a heat pump that was never designed for it?
  2. Does it run with integrity and reliability, on both new and existing installations?
  3. What efficiency gain does it deliver in practice, as opposed to on the bench?

Outcome

The device integrated into the heat pump and ran; development on site continued until the first week of July 2026, seven months after the start. Points 1 and 2 are answered. The measured efficiency gain (point 3) is being analysed and will be added to this page once every figure can be stood behind.

What we do say, and what The Green Village says on its project page: at constant electrical input the heat pump can deliver more cooling or heating capacity, in the order of 10–20% depending on operating range and refrigerant. That is the capacity-side view of the dramatically higher COP the expander delivers.

Why this matters for your installation

  • The device is meant for industrial heat pumps from roughly 100 kW thermal capacity, new or existing.
  • It has no rotating components in the refrigerant stream.
  • It suits subcritical cycles with multiphase refrigerant flow — the everyday case in cold storage, process cooling and heat pumps below the critical point.

If you run an installation like that and want to be the next pilot, get in touch.

Source: The Green Village — project page

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