The hydraulic plan was quickly sketched by hand

With the DUVbox 2×3 (DUV = double changeover valve), a buffer cylinder can be loaded in two zones for hot water and heating operation.

The result almost knocked us off our feet: First, the upper part of the buffer was loaded cleanly in two passes from about 25°C to about 37°C and then to 49°C; then the whole thing was repeated in the lower zone without any mixing of the two zones being observed!

Thermographic loading test rSTOR buffer cylinder with heat pump and DUVbox 2×3

We have shortened the time-lapse thermographic video of the experiment to 34 seconds.

Afterwards, there were Christmas biscuits and coffee on St Nicholas' Day

We will be happy to discuss why you need a buffer at all and what stratification has to do with the efficiency of the heat pump (COP, JAZ) in more detail in our next Practical seminar Arnsberg 2025 on Tuesday, 11, Wednesday, 12 or Thursday, 13 February 2025, where we will give you a live demonstration of the new test together with the already known tests "Condensing boiler benefits without hydraulic separator" and "Thermostatic balancing of air heaters and single-pipe heating circuit".

All those who have not yet registered do so best nowThere is a maximum of 40 places available per day (minus the 15 master students on Tuesday, 11 February 2025)!

Till-Marlo Lüking, Hans-Stefan Albers and Hans-Georg Baunach (from left to right) look forward to meeting you

For energy consultants: Participation can be recognised with 8 DENA points by the HWK Südwestfalen (subject to a fee).

Another tip for all those who want to come: Put on warm jackets and scarves; the heat pump turns the lab into a draughty cold room!