= M. J. Dauncey
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<M. J. Dauncey> is a researcher who developed methods for measuring human energy use with <calorimetry>. A 1978 study with collaborators described an instrument combining <direct calorimetry> with an open-circuit <indirect calorimetry> system for continuous observations lasting at least 24 hours.<A human calorimeter for the direct and indirect measurement of 24 h energy expenditure by M. J. Dauncey and others>[Abstract: continuous heat-production/heat-loss measurements and combined methods]{ref}
The direct system removed heat through a water-cooled <heat exchanger>. Control of the wall <temperature> minimized the mean temperature difference across the chamber walls. Evaporative heat loss was inferred from incoming and outgoing wet-and-dry-bulb temperatures together with air <volumetric flow rates>.<A human calorimeter for the direct and indirect measurement of 24 h energy expenditure by M. J. Dauncey and others>[Abstract: heat-sink operation, heat-exchanger control and evaporation measurements]{ref}
For a dimensional example, a steady heat-loss rate of $100\,\mathrm{W}$ over one hour corresponds to $100\times3600=360000\,\mathrm{J}$, or $360\,\mathrm{kJ}$. These are illustrative values. Heat loss and metabolic heat production need not match instantaneously if the body is warming or cooling, which motivates measuring complementary quantities over a defined interval.
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