Modern technology in historic school building

In connection with a renovation in 2022, ten classrooms at the Evangelical School “Stephan Roth” in Zwickau were equipped with the decentralised ventilation units in the DEX3000 series from EXHAUSTO. Since then, teachers and students have been able to enjoy significantly improved indoor air quality in the historic buildings.
Project ID
The current Evangelical School Stephan Roth in the Cainsdorf district of Zwickau can be traced back to 1849. The buildings have a changeable history behind them, including as a polytechnic secondary school and as a primary school in the Free State of Saxony until 2012.
Since then, it has been run by the institution “Christen Machen Schule” as a single-track evangelical primary school, “Stephan Roth”. The Evangelical Schools in Saxony are state-recognised private schools.
The pedagogical and conceptual diversity is gathered in the evangelical profile, which forms the basis of the school’s Christian vision. “Main subject: Humans”, it is consistently highlighted on the school’s website, and the school would like to be able to meet this requirement in connection with the latest initiative to improve the indoor climate for pupils and teachers.
In addition to optimising air quality with the coronavirus pandemic in mind, this also included reducing pathogens in the indoor air. At the same time, the focus was on as high an energy efficiency in the ventilation solution as possible.
Remedial action
It was only possible to use decentralized units
Due to the technical building conditions and the ongoing operation of the school, it was not possible to install a central ventilation system. In connection with the further planning, the managers from the private school first met with Denny Kühnert, Technical Sales of Ventilation Solutions at EXHAUSTO by Aldes, for a reference meeting in a school project that had already been successfully completed.
Together with the planning manager, the engineering company Kunkel (Zwickau), the decentralised unit series EXHAUSTO DEX3000 was selected.
It includes the models DEX3060 (air capacity 150 – 650 m³/h), DEX3090 with an air capacity of 150 – 900 m³/h and DEX3120 with an air capacity of 300 – 1,400 m³/h. All three models are available in a ceiling-mounted or semi-integrated version.
A total of ten DEX3090 units were installed in the ceilings with an air capacity of up to 900 m³/h , corresponding to the size of the classrooms at Stephan Roth Evangeliske Skole. The installation was carried out by a team from InovaTech GmbH (Meerane).
High energy efficiency and heat protection in summer
To ensure that the system could always be operated energy-efficiently with the hygienically required volumetric flow rate, the units were equipped with a PIR sensor and CO₂ sensor. The CO₂ content in the room should not exceed the limit value according to VDI 6040 at 1000 ppm CO₂ in normal use. The planning department and those responsible at the school also placed great importance on a low sound pressure level in the room, so that teaching is disturbed as little as possible. To prevent the intake of smoke-laden outdoor air, the units are equipped with an integrated smoke alarm.
The desired energy efficiency is ensured by the heat recovery, which is achieved via the integrated counter flow heat exchanger with a high efficiency of up to 80%. To protect against heat in the summer, a bypass damper was installed that bypasses the heat exchanger. This provides extra cooling by directing the cool outdoor air into the rooms at night. This ensures that the maximum amount of air is supplied regardless of how many people are in the room.
Two round weather protection grilles (AR 637, 315 mm diameter) of aluminium were installed for each DEX3090 unit in each classroom for use of outdoor and exhaust air. They were partially painted and adapted to the colour of the facade. In the window fronts, blinded windows with external grilles replaced the skylight. In this way, these are also harmoniously integrated into the appearance of the listed building.
AR637
Facade with yellow lacquered grilles for outdoor air/exhaust air AR637

AR637
Blind windows with grilles for outdoor air/exhaust air AR637

DEX3000
Classroom equipped with DEX3000

Data
Modernisation: | 2022–2023 |
Type: | Educational institution |
Manufactured by: | The Evangelical School "Stephan Roth" |
Timetable: | Engineering company Kunkel GmbH, Zwickau |
Installation steps: | InovaTech GmbH, Meerane |
Products:
DEX3000 – Airflow 150 to 1,400 m³/h
- Decentral fans in three different sizes
- Energy-efficient and quiet ventilation solution
- Air exchange adapted to the use of the space
- Filter options adapted to the outdoor air quality (ODA) to achieve the desired supply air quality
- Many options for flexible duct connection
- Easy installation and service as well as quick filter change
Read more about our DEX3000 products here
AR 637 – Exterior grille
- Round external grille for exhaust air and outdoor air from ventilation system
- Diameter 125 to 315 mm
- Rain-repellent slats, spacing 20 mm
- Aluminium, surface anodised, matt.
- Visible screw fixation in the inner collar
- Internally with protective grille 12 mm x 12 mm, Ø 1.2 mm of galvanised steel
(EXHASTO DK does not sell AR 637)