Creating a better climate in hospitals What influence do indoor climate, air quality, architecture and work organisation have on recovery?

Joint press release of TU Braunschweig and TU Berlin

A new interdisciplinary research project is investigating the influence of heat stress and air quality, for example, on the health of patients in hospitals. The project will also examine the effects of the location, equipment and condition of buildings, the layout of patient rooms and work processes on recovery. A new type of sensor network is being used to measure air quality parameters. Scientists from Technische Universität Braunschweig, Technische Universität Berlin and the Charité – Universitätsmedizin Berlin are involved in the project. It is funded by the German Federal Ministry of Economics and Technology (BMWK) with almost €1 million over three years. The aim is to develop energy- and cost-efficient model solutions for the construction, renovation and operation of hospital buildings.

Various wards in different Charité buildings will be included in the research project. “Over the course of three years, we will be able to evaluate the anonymised data of several thousand patients,” says Prof. Dr. Christine Geffers, Director of the Institute for Hygiene and Environmental Medicine at Charité – Universitätsmedizin Berlin. The evaluation includes, for example, blood test results such as electrolyte levels and haematocrit concentrations. “The concentration of this solid component of the blood increases when the volume of fluid decreases. The haematocrit is therefore a marker for fluid loss, for example due to heavy sweating,” explains Geffers. The decrease in electrolyte concentration also indicates salt loss through sweating. “These parameters therefore provide us with objective information as to whether patients may have suffered from heat stress,” says Geffers.

Anonymised information on infections and treatment duration

In addition to the effects of high temperatures and, possibly, high humidity on patient health, infectious parameters from the treatment data are also included in the study: For example, markers for the occurrence of blood poisoning, as well as information on infections with multi-resistant pathogens, SARS-CoV-2 or influenza viruses. The duration of each patient’s treatment is also recorded.

Health data and sensor data are statistically linked

“We then statistically link this health data with the data on indoor climate and air quality recorded by special sensors in the hospital rooms, as well as model-based energy consumption, to create a new type of sensor network,” says project coordinator Prof. Dr. Martin Kriegel, head of the Hermann Rietschel Institute (HRI), Department of Energy, Comfort & Health at TU Berlin. In addition to temperature and humidity, which together determine the indoor climate, the sensors measure the number of particles in the air and the amount of carbon dioxide. “In normal concentrations, CO2 has no direct effect on health, but it is a very good measure of the efficiency of room ventilation,” explains Kriegel. If it works well, for example, the concentration of pathogens in the air can be significantly reduced. In addition to the data from the sensor network, the researchers also want to include information on nitrogen oxide concentrations and particulate pollution at the locations of the hospital buildings in question. “We also want to take into account the formation of particulate matter in the hospital itself and the outgassing of volatile organic compounds, for example from building materials,” says Kriegel.

The location of a building can affect the health of patients

“The influence of building structures on the health of patients is often underestimated,” says Prof. Dr. Wolfgang Sunder, head of healthcare construction at the Institute of Constructive Design, Industrial and Healthcare Construction (IKE) at TU Braunschweig. The location of a building alone is relevant when it comes to the risk of heat stress, for example. If a building has large windows facing south, the amount of solar radiation is very high. Previous studies at the Charité have shown that the climate in patients’ rooms is relevant to their recovery. In these studies, the recovery time for certain lung diseases was reduced from three to two days when the patients were in air-conditioned rooms.

The interaction between ventilation and building structure is still largely unexplored

But what are the health implications of having two people in a room instead of three? Does it matter how rooms are accessed by visitors, how materials are stored, and where staff meeting rooms and lounges are located? “Particularly in intensive care, haematology and oncology, there are various concepts that have been developed to protect particularly vulnerable patients,” says Sunder. However, many interrelationships, such as the interaction between the building structures and the sometimes complex ventilation systems, are still unclear. The Charité’s large and very diverse building stock is particularly well suited to gaining a wide range of insights.

The goal: energy- and cost-efficient model solutions

“At the end of our research project, we want to develop model construction solutions for various areas of the hospital, which can then be used as a blueprint not only for new buildings, but above all for the renovation of existing buildings,” explains project manager Martin Kriegel. This will be particularly important in the future, as 90 per cent of hospitals in Germany were built before the year 2000. “We will pay particular attention to energy- and cost-efficient solutions,” says Kriegel. After all, the money available has to be used as sensibly as possible in the face of tight budgets. The sensor network installed on the wards could play an important role here: as a signalling device in everyday hospital life, it enables the hospital to react quickly and flexibly to changing circumstances, such as hot and cold spells or waves of illness, by changing the operating mode.

Project data

The project “EnOB: EnHance – Energy-efficient hospital premises: Creating a healthy indoor climate and hygienic indoor air quality with minimal energy use” with the funding code 03EN1086A is funded from December 2023 to November 2026 as part of the 7th Energy Research Programme of the Federal Ministry of Economic Affairs and Energy (BMWK). Associated partners are Charité Facility Management (CFM) and Siemens AG.