# Needs and Effluents

Note:
These values are based on an average metabolic rate of 136.7 W/person (11,200 Btu/person/day) and a respiration quotient of 0.87. The values will be higher when activity levels are greater and for larger than average people. The respiration quotient is the molar ratio of CO2 generated to O2 consumed.[1]

## Human needs and effluents mass balance

(per person per day) Credit: NASA MSFC

 Needs (in) Effluents (out) Oxygen = 0.84 kg (1.84 lb) Carbon Dioxide = 1.00 kg (2.20 lb) Food solids = 0.62 kg (1.36 lb) Respiration & Perspiration Water = 2,28 kg (5.02 lb) Water in Food = 1.15 kg (2.54 lb) Food Preperation, Latent Water = 0.036 kg (3.31 lb) Food Prep Water = 0.76 kg (1.67 lb) Urine = 1.50 kg (3.31 lb) Drink = 1.62 kg (3.56 lb) Urine Flush Water = 0.50 kg (1.09 lb) Metabolized Water = 0.35 kg (0.76 lb) Feces Water = 0.091 kg (0.20 lb) Hand/Face Wash Water = 4.09 kg (9.00 lb) Sweat Solids = 0.018 kg (0.04 lb) Shower Water = 2.73 kg (6.00 lb) Urine Solids = 0.059 kg (0.13 lb) Urinal Flush = 0.49 kg (1.09 lb) Feces Solids = 0.032 kg (0.07 lb) Clothes Wash Water = 12.50 kg (27.50 lb) Hygiene Water = 12.58 kg (27.68 lb) Dish Wash Water = 5.45 kg (12.00 lb) Clothes Wash WaterLiquid = 11.90 kg (26.17 lb)Latent = 0.60 kg (1.33 lb) Total = 30.60 kg (67.32 lb) Total = 30.60 kg (67.32 lb)

## References

1. Designing For Human Presence in Space: An Introduction to Environmental Control and Life Support Systems (RP-1324). Ed. Paul O. Wieland. NASA MSFC. Marshall Space Flight Center, Alabama 1994

Available in pdf format from NASA RP-1324 - 20.56 MB
Updates to tables 1 and 2 in appendix I of NASA RP–1324 - 460 kB