Kratky Trombe Wall study

In this study we retrofitted an existing Trombe wall to be able to contain living Kratky based plants. The main goal was to extend the usability of the space as it was in use as a heat-capturing device for the adjacent building only during the colder half of the year, staying closed and unused all the remaining time. Also, the additional water mass contained in the plants' roots and the shading provided by the living plants probably will affect the space's thermal balance affecting the final Trombe wall's performance, which are also an interesting factor to explore. In its normal configuration, the space in question gets quite overheated, so seeing how the plants will react and develop inside a hot TW is another question worth exploring.

Mainly, we have used detailed (in 10-minute normalized intervals) thermal observational data made more than a year before the experiment in and around the TW space, as well as weather data collected at the location, which were supplemented by more readings, in particular, of surface and water temperatures collected at different height levels within the TW space, collected during the Experiment year (July 2022 to June 2023). The year before (July 2021 to June 2022, named Baseline year) was used to contrast both datasets against each others. In addition, after finishing the experiment, during 4 months (July to October 2023, named Post-experiment year) also, bottles with water and no plants were placed in the TW space to outline differences between plants and inert water mass effect on the location. Some additional readings were made, such as CO2 levels, water mass amounts within the space, plants weight and death rates were tracked and recorded as well.

While we cannot compare very fairly the previous Trombe wall to a green Trombe wall space as we had so somewhat alter its configuration to be able to contain plants inside (installed a powerful exhaust and surface ventilation system, added shelves and plants shading the space, introduced some appliances, glass and water increasing thermal mass about 151%, kept the door open most of the year to insure adequate plant aeration, etc.), we can observe a notable difference in the thermal conditions, mainly, an important cooling, humidifying and stabilizing effect on TW cavity air throughout the year, making it much less overheated and volatile compared to the BY.

The detailed thermal observations are available at the hourly and daily charts files, with added sensor locations and experiment timeline. The monthly and yearly summary charts were made from monthly samples of those files using Origin software. Attached drawings describe in detail the geometry and construction of the study location. Diagrams and figures outline the basic concepts in use, and photos show the study locations.