HEPRU on display at the traveling exhibition Wild Weather, developed and produced by Science North in partnership with the Ontario Science Centre.
The HEPRU research facility is located in Montpetit Hall located in the vibrant downtown campus of the University of Ottawa. The research unit houses state-of-the-art laboratories equipped with environmental chambers as well as an altitude chamber designed to simulate real-world conditions from sea-level to the high mountains.
Additionally, the world’s only functioning direct human air calorimeter is housed within the HEPRU unit. This unit provides a gold standard method for measuring whole-body heat exchange in a wide-range of temperature and humidity conditions.
The HEPRU research facilities provides a unique environment with an unparalleled capacity to conduct comprehensive research programs dedicated to the evaluation of the human response to different environments during the performance of leisure, sport or work related activities in people of all ages as well as those with medical health conditions.
Read more about the facilities at HEPRU and browse our image gallery below.
The research facility is equipped with three stand alone environmental temperature and humidity controlled chambers. The smallest chamber (8’ wide x 10’ long) is used for training and adaptations studies to extreme heat (air temperature >50°C).
A second large chamber (14’ wide x 16’ long) permits the conduct of studies within a wider range of ambient environmental conditions (i.e., -20°C to +50ºC and 15 to 85% RH). This chamber also houses the direct calorimeter. This innovative technology provides a gold-standard method to perform very precise measurements of the heat dissipated by the human body. By obtaining minute-to-minute measurements of the rate of evaporative and dry heat exchange combined with the measurement of the rate of heat production as assessed by indirect calorimetry, it is possible to obtain an accurate measurement of the rate of body heat storage. The chamber is fully equipped with high precision monitoring units enabling the simultaneous measurement of physiological parameters while the participant is in the calorimeter.
A third larger open space multiple-use environmental chamber (16’ wide x 19’ long) is equipped with a powerful hypoxic technology permitting the independent manipulation of altitude, temperature and humidity to simulate a wide-range of real-life conditions. All chambers are fully equipped with various ergometers (treadmill, semi-recumbent and upright cycle ergometers) and physiological monitoring systems to assess metabolic, cardiovascular, respiratory, thermoregulatory and other responses.
In addition to the various environmental chamber, there are two open space laboratories. The larger (20’ wide x 25’ long) space is equipped with a medical bed, exercise ergometers, physiological monitoring systems, whole-body heating/cooling systems (water perfusion suits with temperature controlled water baths), and other systems. This space is used primarily to conduct studies requiring invasive procedures performed under different thermal states during rest and/or exercise. This includes intradermal microdialysis (for the administration of pharmacological agents to assess the mechanisms governing the regulation of skin blood flow and sweating), measurement of muscle temperatures (multicouple temperature sensors are inserted into the muscle), hemodynamic assessments (includes the measurement of limb blood flow, cardiac output, other).
The second room is equipped with a small exercise testing facility equipped with a metabolic system, treadmill, semi-recumbent and upright cycle ergometers and medical bed as well as blood and urine analysis equipment. This research space is used primarily to conduct patient screening and/or prepare the participants for the experimental trials.
Every living organism is in constant heat exchange with its environment and measuring the heat released from metabolism requires a very sophisticated system—the direct calorimeter. The direct air calorimeter located at the Human and Environmental Physiology Research Unit (HEPRU) at the University of Ottawa was originally developed by Jan Snellen during the 1970s at the Memorial University of Newfoundland.
A world-recognized authority in the area of human thermo-dynamics, Snellen developed one of the very few specialized whole-body calorimeters in the world at that time. This was based on a calorimeter employed by Snellen in studies conducted during his tenure in South Africa (1967–1970). It remained operational until his retirement in 1990, after which it was decommissioned. It was acquired by the director of HEPRU, Glen P. Kenny in 1998 and re-engineered and upgraded.
The main advantages of the Snellen air flow calorimeter are the fast response time, particularly for evaporative heat loss measurements, and the level of precision, particularly at high metabolic rates. With the simultaneous measurement of energy expenditure via indirect calorimetry, the Snellen calorimeter can be used to quantify the change in body heat content. Since the commissioning of the new Snellen air calorimeter, over 100 studies examining human thermoregulation have been conducted and continue to be conducted at our facilities. It is the last known operational human calorimeter in existence.
Additional details on the use of direct calorimetry and the Snellen calorimeter can be found here:
Kenny, G. P., Notley, S. R., & Gagnon, D. (2017). Direct calorimetry: a brief historical review of its use in the study of human metabolism and thermoregulation. European Journal of Applied Physiology, 117(9), 1765-1785.
See below: A gallery of photos showing the Original Snellen air flow calorimeter with J. W. Snellen looking into the partially opened chamber (image is reproduced with permission from the Paul Webb Collection, Wright University Special Collections and Archives) as well as the relocation of the Snellen calorimeter to the Human and Environmental Physiology Research Unit (HEPRU) at the University of Ottawa is provided below.
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