With the help of various actions and energy management evaluations, new measures for increasing energy efficiency at the university are ongoing. Some major measures are described in more detail below.
Energy savings at the THM due to the nationwide gas shortage
From September 2022, measures for saving energy in public buildings were decided by federal ordinance. In addition, the State of Hesse has issued a catalogue of measures with the target of saving 15% in heat energy and 5% in electricity consumption compared to the previous year. By limiting the air temperature in rooms to 19°C, introducing minimal heating of stairwells and corridors as well as lowering the heating circuit temperature at weekends and reducing the outdoor lighting on the campus, the THM has largely achieved the set goals. The 1,330 MWh of heat saved could heat around 60 single-family homes. Compared to December of the previous year, 4.5% energy was saved.
en:key and hydronic balancing in Friedberg
In order to increase energy efficiency and user comfort, a hydraulic balance was carried out on the A and B campuses in 2022 and an individual room control system was installed. To do this, the valves on almost 1,000 radiators were replaced and the system hydraulically balanced. In the process, around 800 en:key valve controllers and a total of 345 wall control units were installed in the rooms in place of the normal thermostatic heads. The respective room sensor records the presence of the occupants and uses this to create an individual usage profile. With this profile, the room temperature is raised by a servomotor on the valve when the room is in use and lowered again at other times. In addition to better user comfort, heating energy costs can be reduced significantly.
Based on the experience gained from projects that have already been implemented, a saving of at least 10% is expected.
Operation optimisation and noise reduction in the LTZ
In 2022, the air volume flows in buildings D13, D14 and D15 were adjusted with considerable energy and noise reduction. The evaluations so far show energy savings of up to 40% compared to the same month last year, particularly in terms of heat. The electricity consumption of the ventilation system was also noticeably reduced.
Optimization and heat distribution on the C campus
The conversion and renovation of a district heating distribution network was planned and successfully implemented on the C-Campus in Giessen in 2020 and 2021.
Operation optimisation in building D16
In 2021, the control technology in building D16 was further optimised. Previously, the rooms were heated up to 20°C and then cooled down from 20.5°C. The so-called "dead band" was increased from 0.5 to 2.0 Kelvin in the course of the optimisation measure.
By changing the sequences, an energy saving of 14% could be achieved in Building D16 in the last heating period compared to the previous year.
Facade renovation of Building A5
In building A5 on the Friedberg campus there are mostly laboratory rooms from Department E Maschinenbau, Mathematics, Natural Sciences and Data Processing as well as business. Due to the year of construction, there were high heat losses through the facade.
The steel girders and the Reglit glazing did not offer good thermal insulation, so that an extensive renovation took place here in 2019. Instead of the previous glazing, insulated aluminum sandwich elements now adorn the façade and ensure noticeable energy savings and better user comfort. The windows and sectional doors were also modernized in terms of energy and the latter were also enlarged in the process.
Facade renovation of Building A7
The facade of Building A7 on the Friedberg campus was renovated in 2020. For this purpose, the semi-transparent components and windows were replaced. The insulated aluminum sandwich elements of the new facade reduce the heat loss of the building and at the same time ensure better user comfort.
Operation optimization building B21
In the course of the project "Development of an energy concept for a CO2-neutral university" - ECO2 for short - an operational analysis and optimization of the ventilation system in the rented Roxy Cinema in Giessen was carried out.
The aim was to check the function of the digital building automation newly installed in autumn 2016 and to determine suitable optimized operating parameters. This should enable increased user comfort with reduced energy requirements. The new parameters were based on measurements of room temperature and CO 2-Concentration during lectures. These were also carried out and evaluated by students of the "Building Systems Engineering" course as part of a project work.
The system parameters have already been adjusted based on the new findings. Particularly positive: The changes in the room climate have been well received by the users.
With the new control and the changed operating parameters, around 25% of primary energy is saved. This corresponds to a reduction in CO 2-emissions of about 9 tons per year.
