Room Calorimeter

A room calorimeter measures a patient’s energy expenditure or metabolism under various climactic conditions. The measurement technique – known as room calorimetry – measures the difference between O2 and CO2 concentrations consumed and expelled. This difference can then be used to determine the energy consumption. In addition to measuring gas concentrations, these room calorimeters, or commonly referred to as respiration chambers, can also be used to analyse food intake, faeces output and blood samples. Respiration chambers are airtight cabins measuring two by three metres in which patients or trial subjects are ‘locked’ for one or more days. These chambers have a bed, television, toilet, TV, internet and all other basic comforts.

Why do we need it?

The central question this research is trying to answer is how much energy (read: food) man needs to survive. In a world where obesity is quickly reaching devastating new proportions, this type of research helps us understand the effects of dieting, of exercising twice a week, of consuming energy drinks or other nutritional supplements and the gives us new insight into the metabolism of older individuals with chronic disorders. This is the basic function of the room calorimeter.

What are the advantages?

Before the Faculty of Humane Biology at Maastricht University designed these respiration chambers thirty years ago, we were unable to measure metabolism with this type of accuracy. IDEE built these chambers in collaboration with the Human Biology Department. Five new whole-body room calorimeters with high-tech analysis technology have been installed so far. The advantage of using a whole-body room setup is that it allows for real-time monitoring of metabolic parameters and energy expenditure, making it an ideal research instrument for metabolic clinical nutrition research.

Any additional features?

The University of Warwick (UK) approached Maastricht Instruments to request a double respiration chamber like the one at the HB Department in Maastricht. With the help of the HB Department (adviser and supplier of analytic software) and strategic partner DSM Resolve (airtight chambers and accompanying climate control) MI was able to successfully complete the assignment. Warwick will soon be able to launch their research studies with the room calorimeters. The room calorimeters have also been delivered to the Singapore Institute of Clinical Sciences in 2013.

What do we think?

“The Dutch are often quite modest but I will happily say that this is the highest quality respiration chamber in the world,” according to Emile Arnoldussen, business developer at Maastricht Instruments.

Respiration chambers analyse metabolism and energy expenditure

The advanced respiration chambers developed by a consortium of scientists and technicians in Maastricht are beginning to draw international attention. Having already generated interest in England, Maastricht Instruments BV, a subsidiary of the FHML and Maastricht UMC+, has now landed a large order from Singapore. The respiration chambers, also known as room calorimeters, are used to measure human energy expenditure and metabolism. Test subjects enter this closed-circuit chamber for several days at a time (a maximum of five), where all meals are served through a small window. Urine samples are collected in special containers and faeces is frozen in an automated deep-freeze toilet for later research.

Fresh air is pumped into the room and the air expelled by the test subject is extracted from the room. Scientists continuously monitor and analyse the O2 and CO2 concentrations of incoming and outgoing air to determine the test subject’s energy expenditure and metabolism. For metabolism research, scientists examine how the body processes food and converts it into energy. We now know that it takes 0.8 litres of oxygen to burn one gram of carbohydrates (like bread or pasta), resulting in a CO2 output of 0.8 litres as well. This ratio is very different when burning fat: it takes 2 litres of oxygen to burn one gram of fat, which produces 1.4 litres of CO2.

If you can measure how much energy a person needs per day, you can also figure out how much food they need. This is known as our energy balance. In a world where obesity is reaching devastating proportions, it is easy to see how important this research can be.

The results of this metabolism research can be used to improve our food and nutritional supplements, which is particularly relevant for research on overweight and obesity. But respiration chambers are also used to research chronic diseases like COPD and diabetes. Think of a respiration chamber as a metabolic laboratory that can determine the energy expenditure of sleeping test subjects or the performance of world-class athletes on an exercise bike.

A respiration chamber consists of three components: the chamber itself, which contains a sophisticated ventilation and climate control system, a deep-freeze toilet, a washbasin, a foldable table, a bed, a television and internet;a high-tech gas measurement and analysis system software for collecting and analysing data.

The Department of Human Biology and the NUTRIM research institute, part of Maastricht UMC+, play a pioneering role in this type of human research. With the technical support of Maastricht Instruments BV and DSM Resolve, these respiration chambers can be delivered worldwide. Two such chambers have already been delivered to the University of Warwick in England and a third order for two more chambers was recently placed by the Singapore Institute of Clinical Science (SICS). More information about the Singapore room calorimeters and the images below..


  • Research system for validation studies
  • Full turnkey solution for site-specific respiration chamber setup
  • Commercialization license for research market

Maastricht University, School for Nutrition, Toxicology and Metabolism. Department Human Biology.

DSM Resolve, Geleen

A dual-respiration chamber system withy automated calibration – Schoffelen et al (1997)

Freek Boesten
Business development