Human equivalent: Difference between revisions
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==In sustainability discussions== |
==In sustainability discussions== |
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The '''human equivalent''' (H-e) indicates, for a given amount of energy expenditure, the relative quantity of energy needed for human [[metabolism]], assuming an average human energy expenditure of 12,500kJ per day and a [[basal metabolic rate]] of 80 watts. |
The '''human equivalent''' (H-e) indicates, for a given amount of energy expenditure, the relative quantity of energy needed for human [[metabolism]], assuming an average human energy expenditure of 12,500kJ per day and a [[basal metabolic rate]] of 80 watts. |
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For example, if our bodies run (on average) at 80 watts, then a light bulb running at 100 watts is running at 1.25 human equivalents (100 ÷ 80) i.e. 1.25 H-e. |
For example, if our bodies run (on average) at 80 watts, then a light bulb running at 100 watts is running at 1.25 human equivalents (100 ÷ 80) i.e. 1.25 H-e. |
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Revision as of 15:48, 29 May 2009
In chemistry and medicine
The human equivalent or human equivalent dose (HED) is the quantity of a chemical that, when administered to humans, produces an effect equal to that produced in test animals by a smaller dose.[1] Calculating the HED is a step in carrying out a clinical trial of a pharmaceutical drug.[2]
In sustainability discussions
The human equivalent (H-e) indicates, for a given amount of energy expenditure, the relative quantity of energy needed for human metabolism, assuming an average human energy expenditure of 12,500kJ per day and a basal metabolic rate of 80 watts. For example, if our bodies run (on average) at 80 watts, then a light bulb running at 100 watts is running at 1.25 human equivalents (100 ÷ 80) i.e. 1.25 H-e.
The human equivalent assists understanding of energy flows in physical and biological systems by expressing energy units in human terms: it provides a “feel” for the use of a given amount of energy. A professional cyclist can maintain a rate of energy use of 400 watts, or 5 H-e, for a prolonged period. [3]
See also
- Carbon accounting
- Emission standard
- Global warming potential
- Carbon dioxide equivalent
- Bicycle performance