Thermal equivalent of oxygen

In some situations, discussed in more detail later, heat production has to be estimated from oxygen consumption alone. If a respiratory quotient of 0.82 and a thermal equivalent of 20.0 kJ/1 are assumed, then departures from this RQ in the range of 0.7-1.0 cause a maximum bias of no more than 3.5 per cent in the estimate of heat production. A further simplification is possible in respect of protein metabolism. The thermal equivalent of oxygen used for protein oxidation is 18.8 kJ/1, not very different from the value of 20.0 assumed for carbohydrate and fat oxidation. 

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