Alexander Pichlhöfer

Mr. Alexander Pichlhöfer

TU Wien - Institute of Materials Science and Technology
orcid

Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
25 August 2021 in Sustainability
Verified
Journal Article
Open access
PDF file
Alexander PichlhöferAlexander Pichlhöfer
Alexander Pichlhöfer
Eldira SestoEldira Sesto
Eldira Sesto
JHJutta Hollands
Jutta Hollands
Azra KorjenicAzra Korjenic
Azra Korjenic
Humans spend more than 80% of their lives indoors resulting in an increased demand for high indoor air quality (IAQ). At the same time, indoor air tends to be at least twice as polluted as outdoor air, and health threats caused by long-term exposure to indoor air pollution are rising. Few experiments under real-life conditions have demonstrated positive effects of indoor plants on parameters related to IAQ, resulting in improved humidity and temperature, reduced particulate matter concentration and CO2 levels. Indoor living walls allow the presence of many plants—without taking up valuable floor area. This article presents the results of conducted measurements on four do-it-yourself green walls planted with different plant species that are typically used for vertical indoor greenery (golden pothos, Boston fern, spider plant and a combination of plants) in a school setting. Besides the parameters of air humidity and temperature, CO2, mold spore and particulate matter levels, influences on room acoustics were investigated. Based on a custom-developed evaluation matrix, the plants were compared with each other and a reference without plants. The results show that no species led to deterioration of IAQ. Golden pothos had the most substantial effect and delivered improvements in all examined parameters.

14 June 2023 in Sustainability
Verified
Journal Article
Open access
PDF file
Alexander PichlhöferAlexander Pichlhöfer
Alexander Pichlhöfer
Azra KorjenicAzra Korjenic
Azra Korjenic
ASAbdulah Sulejmanovski
Abdulah Sulejmanovski
ESErich Streit
Erich Streit
Heat transfer through building envelopes is a crucial aspect of energy efficiency in construction. Masonry walls, being a commonly used building material, have a significant impact on thermal performance. In recent years, green roofs and walls have gained popularity as a means of improving energy efficiency, reducing urban heat islands, and enhancing building aesthetics. This study aims to investigate the effect of ivy (Hedera helix) greening on heat transfer through masonry walls and their corresponding surface temperatures. Ivy was chosen as a model plant due to its widespread use and ability to cover large surface areas. The results of this study suggest that ivy greening can have a significant impact on the thermal performance of masonry walls. During winter, the heat transfer coefficient of greened walls was found to be up to 30% lower compared to non-greened walls. This indicates that ivy greening can help reduce energy consumption for heating and thus improve the energy efficiency of buildings. In addition, the surface temperature under the ivy was found to be significantly higher than on the bare wall during winter. However, during summer, the surface temperature under the ivy was lower than on the bare wall, which may help reduce cooling energy consumption. The results of this study are consistent with previous research in the field. Overall, this study provides valuable insights into the potential benefits of ivy greening on the thermal performance of masonry walls.

27 February 2025 in Sensors
Verified
Journal Article
Open access
PDF file
MGMehmet Akif Gümüser
Mehmet Akif Gümüser
Alexander PichlhöferAlexander Pichlhöfer
Alexander Pichlhöfer
Azra KorjenicAzra Korjenic
Azra Korjenic
Smart irrigation systems play a crucial role in water management, particularly in urban greening applications aimed at mitigating urban heat islands and enhancing environmental sustainability. These systems rely on soil moisture sensors to optimize water usage, ensuring that irrigation is precisely tailored to plant needs. This study evaluates the performance of four commercially available capacitive soil moisture sensors—TEROS 10, SMT50, Scanntronik, and DFROBOT—across three different substrates under controlled laboratory conditions. A total of 380 measurements were conducted to assess sensor accuracy, reliability, and the influence of insertion technique on measurement variability. Results indicate that while all sensors adequately cover the moisture ranges critical for plant health, their accuracy varies significantly, highlighting the necessity of substrate-specific calibration. TEROS 10 exhibited the lowest relative deviation and highest measurement consistency, making it the most reliable among the tested sensors. DFROBOT, despite being the least expensive, performed comparably to SMT50 and Scanntronik in certain conditions. The findings provide valuable insights for selecting and calibrating soil moisture sensors in smart irrigation applications, ultimately contributing to improved water efficiency, plant vitality, and sustainable building-integrated greenery.

28 February 2024 in Sensors
Verified
Journal Article
Open access
PDF file
FTFlorian Teichmann
Florian Teichmann
Alexander PichlhöferAlexander Pichlhöfer
Alexander Pichlhöfer
ASAbdulah Sulejmanovski
Abdulah Sulejmanovski
Azra KorjenicAzra Korjenic
Azra Korjenic
In the validation of microclimate simulation software, the comparison of simulation results with on-site measurements is a common practice. To ensure reliable validation, it is crucial to utilize high-quality temperature sensors with a deviation smaller than the average absolute error of the simulation software. However, previous validation campaigns have identified significant absolute errors, particularly during periods of high solar radiation, possibly attributed to the use of non-ventilated radiation shields. This study addresses the issue by introducing a ventilated radiation shield created through 3D printing, aiming to enhance the accuracy of measurements on cloudless summer days with intense solar radiation. The investigation employs two pairs of sensors, each comprising one sensor with a ventilated and one with a non-ventilated radiation shield, placed on a south-oriented facade with two distinct albedos. Results from the measurement campaign indicate that the air temperature measured by the non-ventilated sensor is elevated by up to 2.8 °C at high albedo and up to 1.9 °C at a low albedo facade, compared to measurements with the ventilated radiation shield. An in-depth analysis of means, standard deviations, and 95% fractiles highlights the strong dependency of the non-ventilated sensor error on wind velocity. This research underscores the importance of employing ventilated radiation shields for accurate microclimate measurements, particularly in scenarios involving high solar radiation, contributing valuable insights for researchers and practitioners engaged in microclimate simulation validation processes.

31 October 2018 in MATEC Web of Conferences
Verified
Journal Article
Open access
WSWolfgang Schwarz
Wolfgang Schwarz
Alexander PichlhöferAlexander Pichlhöfer
Alexander Pichlhöfer
AHAnthony van Den Hondel
Anthony van Den Hondel
HEHernani Esteves
Hernani Esteves
A galvanic zinc anode system, composed of a zinc mesh embedded into a proprietary solid matrix with ion exchange properties, was developed by CAS. The solid matrix of the embedded zinc anode system (EZA) is based on a tecto-alumosilicate-binder containing additives that prevent passivation of the zinc anode, assure high and durable galvanic activity of the zinc anode and high and durable adhesion towards the concrete overlay. The efficiency of the EZA, applied to concrete members of four types of civil structures – abutment of a road bridge in the Styrian Alps in Austria (2007), support-beams for the bearings of four viaducts in Den Hague in the Netherlands (2009) and a parking deck in Saas Fee in Switzerland (2011), was monitored with embedded reference cells and macro cell sensors. Data collected over a period of up to 10 years show that the EZA protects the steel reinforcement efficiently and reliably. An advanced EZA system – based on the novel shrinkage controlled EZA binder (SEZAC) covered with a novel water vapor permeable epoxy/PU membrane was installed July 2017 at the tunnel entrance of a federal road in the Styrian Alps. The EZA exposed to harsh weathering conditions proves to be efficient in protecting the steel reinforcement from corrosion.

5 August 2022 in Energies
Verified
Journal Article
Open access
PDF file
Alexander PichlhöferAlexander Pichlhöfer
Alexander Pichlhöfer
Azra KorjenicAzra Korjenic
Azra Korjenic
Electrochemical low-cost sensors, suitable for the monitoring of different air quality parameters such as carbon monoxide or nitrogen dioxide levels, are viable tools for creating affordable handheld devices for short-term or dense air quality monitoring networks for long-term measurements and IoT applications. However, most devices that utilize such sensors are based on proprietary hardware and software and, therefore, do not offer users the ability to replace sensors or interact with the hardware, software, and data in a meaningful way. Initiatives that focus on an open framework for air quality monitoring, such as the AirSensEUR project, offer competitive open source alternatives. In this study, we examined the feasibility of the application of such devices. Five AirSensEUR units equipped with chemical sensors were placed next to a reference air quality measuring station in Vienna, Austria. During co-location, concentrations of 0.20 ± 0.06 ppm, 7.14 ± 8.66 ppb, and 17.58 ± 9.90 ppb were measured for CO, NO, and NO2, respectively. The process of evaluating the performance of the low-cost sensors was carried out and compared to similar studies. Data analysis was carried out with the help of the basic functions in MS Excel. We investigated the linear correlation between the sensor and reference data and thus calculated the coefficient of determination, the average and maximum residuals, and the correlation coefficient. Furthermore, we discuss sensor properties in regard to selectivity and long-term stability.