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WPI Unit 12t1C 0045-6~4-1%6 - SENSIBLE AND LATENT HEAT LOSSES FROM OCCUPANTS OF SURVIVAL SHELTERS OCCUPATIONAL HEALTH RESEARCH AND TRAINING FACILITY Decem••r 1966 U.S. DEPARTMENT OF HFALTH, EDUCATION. AND WELFARE Public Health Swvice Washington, D.C. D D C Dwi,,ution of oIs docume- m is unlimited-r tA Y&R 1\4 1967

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Page 1: SENSIBLE AND LATENT HEAT LOSSES FROM OCCUPANTS OF … · sensible and latent heat losses from occupants of survival shelters occupational health research and training facility cincinnati,

WPI Unit 12t1C0045-6~4-1%6

- SENSIBLE AND LATENT HEAT LOSSESFROM OCCUPANTS OF SURVIVAL SHELTERS

OCCUPATIONAL HEALTH RESEARCH AND TRAINING FACILITY

Decem••r 1966

U.S. DEPARTMENT OF HFALTH, EDUCATION. AND WELFARE

Public Health SwviceWashington, D.C. D D C

Dwi,,ution of oIs docume- m is unlimited-r

tA Y&R 1\4 1967

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Work Unit i221COCD-PS-64-126

SENSIBLE AND LATENT HEAT LOSSESFROM OCCUPANTS OF SURVIVAL SHELTERS

OCCUPATIONAL HEALTH RESEARCH AND TRAINING FACILITYCINCINNATI, OHIO

CLARK M. HUMPHREYSAUSTIN HENSCHELDOUGLAS H. K. LEE

Prepared tor the

OFFICE OF CIVIL DEFENSEDEPARTMENT OF THE ARMY-OSA

Through. the

DEPARTMENT OF HEALTH, EDUCATION, AND WELFAREPUBLIC HEALTH SERVICE

DIVISION OF HEALTH MOBILIZATION

AVAILABILITY NOTICE

DISTRIBUTION OF THIS DOCUMENT IS UNLIMITED

DECEMBER 1966

REVIEW NOTICEThis report has been reviewed in the Office of Civil Defense and approved for publication. Approvaldoes not signify that the contents necessarily reflect the views and policies of the Office of Civil Defense.

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SENSIBLE AND LATFNT HEAT LOSSES

FROM OCCUPANTS CF SURVIVAL SHELTERS

SUMARY

Six figures have been prepared showing the sensible and latent heat ex-change rates from clothed and nude individuals at various environmentalconditions and at three metabolic rates. Data are also included by which

S the heat exchange rates for the "standard individual" may be correctedfor "non-standard" groups.

'.-

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j HEAT LOSSES FROM OCCUPANTS OF SURVIVAL SHELTERS

INTROD1UCTION

Man's survival requires that, except for short periods of time, a ratheraccurate balance must be maintained between the rate of metabolic heatproduction within ° I Mly, and the rate of heat loss from the body tothe surrounding environment. At normal environmental concitions, bothsensible heat and latent heat (moisture) are given up by the body, andthese in turn, tend to raise the temperature and humidity of the ambientair. In homes or other spaces having low population density, the changesin environmental conditions due to the heat given off by the occupantsare quite small. However, in places of public assembly having high pop-ulation density, the sensible heat and moisture contribution from theoccupants can have a marked effect on the ambient conditions, andadequate ventilation or cooling is required to maintain a comfortableenvironment.

In times of emergency, a survival shelter will become a place of publicassembly and may be expected to have a high population density, Exceptin rare instances, complete air conditioning will not be available andthe entire metabolic heat production of the shelter occupants will haveto be removed by ventilation, or by heat transfer to the exteriorsurfaces of the shelter.

The ventilating system for the average shelter will be designed, not toprovide complete comfort for the occupants, but to enhance their chancesof survival during the required period of occupancy. The amount of ven-tilation air that can be supplied may be minimal for several reasons.In case of disaster, public power supply citnot be relied upon, and ven-tilating fans may have to be operated manually by the shelter occupants,or by power from a small engine-generator unit within the shelter, ifone is available. The outside air is also likely to be contaminated incase of disaster, and equipment will probably be provided for treatingonly a minimal amount of air.

The designer of the ventilating system for a survival shelter needsaccurate data on 4he sensible heat and moisture loss from the humanbody,to establish realistic design requirements. This need has long beenrecognized by the Office of Civilian Defense, and a request for such datawas made to the Occupational Health Research and Trcining Facility ofthe U. S. Public Health Service in Cincinnati. The request specifiedthat the data should cover the following ranges of conditions:

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HEAT LOSSES FROM OCCUPANTS OF SURVIVAL SHELTERS

(a) Dry-bulb temperatures - 50 to 120 F(b) Air velocities - still air and 100 ft./min.(c) Mean radiant temperatures - from 10 F below to 10 F

above air temperature(d) Metabolic rates - 300, 400 and 600 Btu/hr.(e) Clothing - standard and minimal

It was further requested that the results should be presented in such away that they could be made applicable to children and adults, male andfemale.

BACKGROUND

The temperature of the humen body remains relatively constant over awide range of environmental conditions. This is the result of the closebalance which is maintained between heat production within the body(metabolism) and the heat loss from the body. The heat interchangesinvolved in this heat balance are described by the equation:

M= E ± R ± C ± S (1)

Where:

M = rate of metabolic heat production within the bodyE = rate of evaporative heat lossR = rate of radiative heat loss or gainC = rate of convective heat loss or gainS = rate of heat storage within the body, resulting

.n a change in body temperature

The rate of metabolic heat production, M, is always positive. Underordinary conditions, when the skin temperature is higher than the dewpoint of the air, E is also positive. R and C are positive when theskin temperature is higher than that of the surrounding walls and air,but negative when it is lower. Storage, S, is positive when the body isgaining heat and its temperature is rising, and negative when the rateof heat loss exceeds M, and the body temperature is fallivg. While thebody can store or lose heat for short periods of time without seriousconsequences, in spaces intended for prolonged occupancy conditions mustbe such that S 0.

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HEAT LOSSES FROM OCCUPANTS OF SURVIVAL SHELTERS

Ideal conditions are experienced when the metabolic heat, M, is justbalanced by the minimal evaporative loss plus radiation and convection.As environmental temperatures increase, R and C losses decrease and Eincreases to maintain the necessary heat balance. When the skin, air andsurrounding surface temperatures are equal, R an6 C become zero and Emust equal M. If ambient air and surface temperatures are above skintemperature, the body gains heat by radiation and convection (R and Cbecome negative), and E must equal the arithmetic sum of M + R + C. Fora more complete discussion of the adaptions of the human body to vwryingenvironmental conditions see References 1 and 2.

Some of the more important factors which influence heat exchange betweenthe human body and its environment are air temperature, humidity, airmotion, temperature of surroundings, activity, and the type and amountof clothing. There are also human factors such as age, sex, acclimatiza-tion and individual variability to further complicate the problem (seeReference 3).

In view of the many variables involved, it is not surprising thatdifferent investigators have arrived at somewhat different conclusionsregarding heat losses from the body.

CALCLLATION (F HEAT LOSS DATA

The equation for sensible heat loss from the body (R + C) which wasjudged to be best suited to this particular problem, is given by Burton( 4 ).It is applicable to both nude and clothed subjects. Assuming the averageman to have a body surfact•. of 20 square feet, the equation may bewr i tten:

ts taR + C r 22.8 (2)

Where:

R + C = sensible heat loss from the average man, Btu nrts = skin temperature, deg. Fta - air temperature, deg. FIc - insulation of clothing, in -lo units

r insulation of air, in clo units

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HEAT LOSSES FROM OCCUPANTS CF SURVIVAL SHELTERS

The clo(1), defined in terms of resistance rather than conductance units,is

Deg. F0.88 fltu/(hr)(sq. ft.)

Deg,. C___or 0.18 Deg./

The ordinary business suit has an insulating value of approximately1 CIo.

SKIN TEPERATURES

Available data on mean skin temperatures at various air temperatures andvelocities show considerablh variation at the lower air temperatures.However, at air temperatures above 90 F, the data are in good agreement.Skin temperatures used in this study are plotted in Figure 1. Curves ofskin temperatures for clothed subjects were constructed on the basis otdata from several sources.( 5 ' 6 '.7 Skin temperatures for nude subjectswere plotted from an equation given by Gagge, et al.( 6 ) The questionableaccuracy of skin temperature data at lower air temperatures is not con-sidered important in this study. In practice, if a shelter environmentis col or cold, the shelter occupants would put on additional clothingto provide comfort. Enough clothing should be worn so that Lhe totalheat loss trom the body will not exceed the metabolic rate.

CLOTHING

Data were requested for shelter occupants wearing standard and minimalclothin,. Fbu- standard clothing, ;i• ordinary business suit has beenassun.ed. The value of 1c for such clothing, when dry, is approximately1 cIo, and this value has been used in the cal ulation of heat 'lossesfrom clothed subjects.

Shorts for men and halter and shorts for women would probably constituteminimal attire. The heat losses from occupants in minimal clothing wouldbe essentially the same as from nude subjects, particularly alter theclothing becomes wet with perspiration. Data have therefore been calcu-lated for nude su'jects, for whom Ic r 0.

The insulation of the air, Ia, is a function of the air velocity. Valuesof la are plotted in Figure 2.( The air velocity for which I1 valuesshould be selected varies with the_- activity of the subject. At elevatedmetabolic rates the activity of the subject results in additional air

w

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HEAT LOSSES FROM OCCUPANTS (F SURVIVAL SHELTERS

movement over the body which must be added to the normal air motion ofthe environment to obtain the effect:ve velocity. A table of these air-velocity corrections for various metabolic rates is given in Reference3.In this study normal air velocities of 30 and 100 feet/min. have beenincreased to 80 and ISO feet/mmin., respectively, for calculation of heatlosses at a metabolic rate of 600 Btu/hr.

RESULTS

Equation 2 has been used to calculate sensible heat losses, R i C, fromthe human body for various air temperatures and air velocities. Thelatent loss~s, E, were then calculated to satisfy the heat balance equa-tion (No. 1) assuming no positive heat storage. The results are plottedin Figures 3 through 8. Figures 3, 4, and 5 are for clothed subjectsand 6, 7, and 8 for nude subjects. The scales along the left side ofeach figure show the heat loss rates from an average man having a sur-face area of 20 square feet. The right ind scale gives heat loss ratesper square foot of body area.

In Figures 3 through 8 the mean radiant temperature (W1T) is assumed tobe the same as the air temperature. However, the figures may also beused for conditions where the MWT differs somewhat from the air tempera-ture by considering the effective environmental temperature to be themean of the air temperature and the MRT.( 4 ' 5 ) For example, if body heatloss is desired for an environment where the air temperature is 90 F andthe MgR 100 F, the answer can be found along the 95 F line.

Values from Figures 3 through 8 are for the average person having a sur-face area of 20 square feet and a supine resting metabolic rate of300 Btu,/hour or IS Btufhour per square foot of body area. Body areavaries widely from person to person, and the metabolic rate per squarefoot of surface area varies somewhat with age and sex. To provide datafor modifying the heat transfer rates given in tbt- figures, so that theymay be made applicable to non-standard groups of individuils, Table 1and Figures 9 and 10 have been included. Table 1 gives the averageheight and weight of white ,,,ales and females of various ages in theUnited States. Data for the table were taken from Reference 10. Theapproximate body surface area may he determined from the DuBois BoiySurface Chart of Figure 9. The average supine Icsting metabolic rate persqviare foot of body area for males and females from six to sixty yearscif age may be obtained from Fi ure 10. The curves in this figure wereplotted from Boothby, et al.(I1

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HEAT LOSSES FROM OCCUPANTS OFr SURVIVAL qRELTERS

The ratio of the average metabolic rates of "standard" and "non-standard"groups of individuals, whcn at rest or doing comparable light work, isapproximately the same as the ratio of their supine resting metabolicrates. The metabolic rate, Mx, of the average individual in a "non-standard" group may therefore be approximated by the equation:

=Mbxx Ax. x MMx -- 0 (3)

Where:

Mox = supine resting metabolic rate of "non-standard"individual as determined from Figure 10 - Btu/(hr)(sq. ft.)

Ax = body surface area of the "non-star, ard" individualfrom Figure 9 - square feet

M = metabolic rate of the "standard" man at the indi-cated activity - Btu/hour

300 = supine resting metabolic rate of "standard" man -Bt u/hour

The sensible heat loss from the average individual in a "non-standard"group, under the environmental and activity conditions postulated inFigures 3 through 8, may be calculated by the equation:

h5 A xn h ANhsx X Axxfs ,

Where:

hsx = sensible heat loss from the "non-standard" indl-vidual, Btulhour

Ax = body surface area of the "non-standard'4 individual,square feet

hs = sensible heat loss as given in the right handscale of the mppropriate Figure 3 through 8 forthe standard man. Btu'(hr)(sq. ft.)

The latent heat loss from the non-'tandard individual .. the algebrcicsum of his metabolic rate and sersible hea. loss:

Ex - Mx - hsx (C,5

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HEAT LOSSES FROM OCCUPANTS OF SURVIVAL SHELTERS

EXAMPLE

Determine the sensible and latent heat loss from an average 14 year oldnude boy seated at rest in a room in which the air temperature is 100deg. F, the MRT is 110 deg. F, and the air velocity is 100 feet /min.

SOLUTION

From Table I, the average 14 year old boy is 63 inches tall and weighs108 puunds. From Figure 9, his average surface area is 16 square feet.

Figire 10 indicates a supine resting metabolic rate of 17.1 Btu/(hr)(sq.ft.) for a 14 year old boy. Using Equation 3, his metabolic rate whenseated at rest:

Mx 17.1 x 16 x 400 = 365 Btu/hour300

The sensible heat loss can be determined by Equation 4. In this case themean of the air temperature and the MRT is 105; and from Fi-gure 7, hs isfound to be -22 Btu/(hr)(sq. ft.).

Total sensible heat loss:

hsx = 16 x -22 = -352 Btu/hour

From Equation 5, latent heat loss:

Ex = 365 - (-352) = 717 Btu/hour

MODIFYING EFFECTS OF WET CLOTHING

As indicated alive, the data shown in Figures 3, 4 and 5 for clothedindividuals were calculated on the basis of dry clothing (Ic = 1). Itis quite evident that at the upper end of the temperature range shown inthe figures, an occupant of a shelter will perspire freely and anycl,,thing worn will become damp or wet. Some discussion of the effect ofwet clothing is therefore in order.

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HEAT LOSSES FROM OCCUPANTS OF SURVIVAL SHELTERS

It is generally agreed that as clothing becomes wet its insulating valuedecreases. Inere is no accepted basis for predicting either the degreeof wetness which clothing will attnin under a given set of conditionsor the resulting change in its insulating value. Lee and Henschel( 3used an insulating value for wet clothes (Icw) of 0.4 clo. If this valueinstead of the value for dry clothing were used in Equation 2, thesensible heat gains at the higher temperatures would be increased 48 and64 percent, respectively, for air velocities of 30 and 100 feet perminute. This increased heat gain would be balanced by a correspondingincrease in latent heat loss. The latent loss shown in Figure 4 at120 F and 100 feet per minute velocity would increase from 750 to975 Btu/hr.

It is also generally agreed that as clothing becomes wet the coolingefficiency of sweat evaporation decreases. When evaporation takes placefrom wet clothing instead of from the skin surface, a pazt of the heatrequired for that evaporation is supplied by the air instead of the body.The cooling efficiency may be defined as the ratio of the heat removalfrom the body by evaporation, to the heat which would be required toevaporatt all of the sweat produced by the body.

There are many variables which play a part in determining the coolingefficiency of sweat evaporation and the findings of different inves-tigators are not in agreement. Burton( 4 ) states that cooling efficiencyfor completely wet clothing is equal to

'a

Icw + 'a

If the previously used value, Icw = 0.4, is substituted in this equation,the cooling efficiencies at 30 and 100 feet per minute air velocitieswould be 68 and 57.5 percent, respectively. If this value of 57.5 per-cent is applied to the above calculated evaporative cooling rate of975 Btu/hr, the total latent heat addition to a space at 120 F and 100feet per minute velocity would be

- 1700 Btu/hr per occupant..575

The latent loss from a nude subject at the same environmental conditions,as shown in Figure 7, is 1450 Btu/hr.

It will be noted that Burton's equation for cooling efficiency wouldindicate 100 percent efficiency for a nude subject. Givoni's( 1 2 ) workindicates an average efficiency of 95 percent for the nude body; most of

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HEAT LOSSES FROM OCCUPANTS OF SURVIVAL SHELTERS

thie loss in efficiency is apparently due to drippage of sweat. It istherefore believed that the heat transfer data shown in Figures 6, 7 and8 for nude subjects may be used without correction.

The above discussion would seem to suggest that as conditions in ashelter become warmer, occupants should be encouraged to remove clothingdown to the minimal level. It is agreed by all investigators that in thewarm humid environments likely to occur in survival shelters, occupantswill be more comfortable with a minimum of clothing. And as suggested bythe above example, under some conditions the total moisture addition tothe space may be less from nude than from clothed subjects.

MAXIMUM LATENT HEAT LOSS RATES

All of the above discussion has been concerned with the heat losses re-quired at various conditions to maintain the body in a state of thermalequilibrium. It has been pointed out that at elevated ambient tempera-tures all of the heat loss must take place by evaporation. The requiredextent of this evaporative loss is shown by the latent heat curves inFigures 3 through 8.

The maximum latent heat ioss, Emax, which the body can lose to theambient air is a function of the air velocity, and the difference betweenthe vapor pressure of the sweat on the skin, and the partial pressure ofthe water vapor in the air. This loss may be calculated froir the denom-inator of the equation given on page 15 of reference 3, which is basedon Burton's work.( 4 ) For the average nude man this equation, convertedto the system of units used in this paper, may be written

ax =55.4 (42 - Pw) (6)Ia

Where:

Pw = partial pressure of the water vapor in air - mm Hg.

42 = vapor pressure of the sweat for a skin temperatureof approximately 95 F - mm Hg.

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HEAT LOSSES FROM OCCUPANTS OF SURVIVAL SHELTERS

Values of Emax calculated by this equation are shown by hcrizontal linesin Figures 11, 12 and 13, for air velocities of 30, 100 and 150 feet perminute, respectively. The lines are shown only to the right of the 95 Fdry bulb line, since it is only in this region that the skin temperatureremains relatively constant. (See Figure 1.) It is also only in thehigher temperature region that one is likely to be interested in Emaxvalues. To the left of the 95 F line, the Emax lines would turn downwardbecause of the decreasing skin temperature.

The value of Emax may also be limited by the ability of the body to pro-duce sweat. This limitation is encountered most frequently under hot,dry conditions. Belding and Hatch( 13 ) state that the maximum rate ofsweating which can be maintained by the average acclimatized man over aneight-hour period is 1 liter per hour. The evaporation of this quantityof sweat will produce a cooling effect of approximately 2400 Btu/hr.The 2400 Emax line is shown dotted on Figures 11, 12 and 13. For theattainment of high sweat rates it is essential that the individual besupplied with sufficient drinking water to maintain normal body hydration.

To give meaning to the Emax lines, three relative strain lines have alsobeen drawn on Figures 11, 12 and 13. Lee and Henschel( 3 ) have definedrelative strain as the -atio of the evaporative cooling required tomaintain thermal equilibrium to the maximum rate of evaporative coolingwhich can be maintained in a given environment. For the average nude manthe equation for this relationship may be written

M + 22.8 (ta- 95)

Relative strain = - - (7)55.4 (42 -Pw)(7

la

At any point on the relative strain = 1.0 line, the evaporative coolingrequired to prevent body heat storage is equal to the maximum latentheat acceptance of the environment. This line thus defines the mostsevere conditions under which thermal equilibrium can be maintained.Similarly, the 0.50 relative strain line shows the conditions at whichthe required evaporative cooling is 50 percent of the maximum possible.

It should be noted that if, for example, 2400 Btu per hour is taken asthe maximum possible cooling rate, then the relative strain lines woulddrop vertically d-iwnward from their intersection with the 2400 Emaxline.

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HEAT LOSSES FRM OCCUPANTS OF SURVIVAL SHELTERS

EFFECT OF PHYSICAL IORK ON BODY HEAT LOSS

It is assumed that the average person in a survival shelter will beessentially at rest, and the heat balance Equation (1) presented earlierin this report is for that condition. For a person performing usefulwork on an external system, the heat equivalent of that work would appearas an additional term on the right-hand side of the equation, and theheat loss by other methods required to maintain equilibrium would bereduced by that amount. The heat exchanges for persons at elevatedmetabolic rates may be calculated from the equations included in thisreport.

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BIBLIOGRAPHY

1. Winslow, C. E. A. and L. P. Herrington. "Temperature and HumanLife." Princeton Univ. Press, Princeton, N. J., Chapter 3, 1949.

2. American Society of Heating, Refrigerating and Air ConditioningEngineers. "ASHRAE Guide and Data Book," 1963, Chapter 8.

3. Lee, D. H. K. and Austin Henschel. "Evaluation of Thermal Environ-ment in Shelters." TR-8, U. S. Public Health Service, Division ofOccupational Health.

4. Burton, A. C. "An Analysis of the Physiological Effects of Clothingin Hot Environments." Reports of Assoc. Committee of Aviation Med.Res., C2754, S.P.C. 186, November 24, 1944.

5. Gagge, A. P., C. E. A. Winslow and L. P. Herrington. "The Influenceof Clothing on the Physiological Reactions of the H:;man Body toVarying Environmental Temperatures." Amer. J.our. of Physiology 124,p 30, 1938.

6. Winslow, C. E. A., A. P. Gagge and L. P. Herrington. "The Influenceof Air Movement Upon Heat Losses from the Clothed Human Body."Amer. Jour. of Physiology 127, p 505, 1939.

7. Fahnestock, M. K., F. E. Boys, F. Sargent II, W. E. Springer andL. D. Silver. "Comfort and Physiological Responses to Work in anEnvironment of 75 F a,:d 45 Per Cent Relative Humidity." ASHRAETransactions 69, p 13, 1963.

8. Gagge, A. P., L. P. Herrington and C. E. A. Winslow. "Thermal Inter-changes between the Human Body and Its Atmospheric Environment."Amer. Jour. of Hygiene, 26, p 84, July 1937.

9. Burton, A. C. "Standard Values for the Thermal Insulation of AmbientAir with Different Degrees of Air Movement." Report of Assoc. Com-mittee of Aviation Me(. Res., C2753, S.P.C. Report 185, November 16,1944.

10. Spector, W. S. "Handbook of Biological Data." W. S. Saunders Co.,Table 150.

11. Boothby, W. M., J. Berkson and H. L. Dunn. "Studies of the Energyof Metabolism of Normal Individuals: A Standard for Basal Metabolismwith a Nomogram for Clinical Application." Amer. Jour. of Physiology116, p 468, 1936.

S

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41

12. Givoni, B. "Estimation of the Effects of Climate on Man: Develop-ment of a New Thermal Index." Building Research Station, Technion,Israel Institute of Technology, Haifa, Israel.

13. Belding, H. S. and T. F. Hatch. "Index for Evaluating Heat Stressin Terms of Resulting Physiological Strains." A-iRAE Transactions,62, p 213, 1956.

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TA1.LE I. AVERAGE HEIGHT AND WEIGHT OF MALES AND FEMALES

OF VARIOUS AGES IN TIE U. S. A.

Male Fema I e

Age Height Weight Height WeightYears inches pounds inches pounds

4 40.9 30.2 40.9 37.3

s 1 43.9 43.2 43.6 42.0

6 46.1 47.6 45.8 46.4

7 48.2 52.5 47.9 51.2

8 50.4 58.2 50.0 56.9

9 52.4 64.4 52.0 63.010 54.3 70.7 54.2 70.3

11 56.2 77.6 56.5 79.012 58.2 85.6 59.0 89.7

13 60.5 95.6 60.6 100.3

14 63.0 107.9 62.3 108.5

15 65.5 121.7 63.2 115.0

16 67.3 131.9 63.5 117.617 67.6 140.4 63.6 119.0

18 68.2 147.8 64.3 125.6

19 68.3 151.2 64.7 128.6

20-24 68.4 154.7 63.6 123.025-29 68.3 157.8 63.4 124.730-34 68.1 158.1 63.4 129.5

35-44 ...i 63.1 138.0

45-54 i 62.8 147.855-64 -- -- 62.2 144.5

>64 .. . 61.7 138.5

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95 a~ -0

90 __1_ _ 0_ __

85

wseo

W~ 95

1IJ9 0

CLa

Z 85

z

44

75 /

65a50 60 70 s0 90 100 110 120

AIR TEMPERATURE , DEGREE F.

Figure i Skin Temperatures of Clothed ard Nude Subjects

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0

0

U..

cr

C4

00*0i

_______ 0-13__ Nl'o_____ ______ -4 NSi n

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700 35

600- AIR VELOCITY -30 FT./MIN. ____30 •AIR VELOCITY-IOCFT./MIN.= I II "

1500 w- 25 1,-I 5- ' REQUIRED LATENT HEAT LOSSr oz I

2 400 20 24

0 cc- 300 15

z0200

10(j) L..

FE 0o Ion ___ ___

LL

z d

U.v) -200 -0-

l'- -300' - 15 UJ4 x

-4001 L -2050 60 70 80 90 100 110 120

AIR TEMPERATURE, DEGREE F.

Figure 3 -Heat Loss f rorr Clothed Supine Rest ing Subject. MetaThlicRate =300 Btu'hr.. (15 Btu'(hr (sq. ft.)), S 0

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800 1 . 40

-- AIR VELOCITY - 30 FT./ MIN.- AIR VELOCITY -100 FT.-/ MIN. •

6 REQUIRED LATENT HEAT LOSS 30 ,

Z 500 25

w

z 1oo0 400 20

3 -00 15g

i _Co --i 200 10 0

0 1-ý

Z 100 50

LLR TEPRAUE 100RE 5F.4 Ir " 4 1 , .• o ., l ( ' ( l ) l , i S ', ,' t . ., .t '! -U)," '

0) 0.

S U,

J-,

V) _

-J -200 1-0

Id -300 -- 15

-400- -20_50 60 70 80 90 l00 110 120

AIR TEMPERATURE, DEGREE F.

F&iv4 - lirmt Lo-.s iror- ( Iotlii ý . St i l.

'A lk C'v 0 l ýi - -

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1000 50

900 .... AIR VELOCITY- 30 + 50= BO FT./MIN. 45- AIR VELOCITY-100 + 50=150 FT./MIN.

80SEQoEo* 40I/,REQUIRED LATENT HEAT LOSS

S700 I35co

p600 30

zW 5

i oo0-• ,o25

z

00

4; 00 20 0.

zw U-

300 150

o 200 - 0

z c-100

.5

00 .0 ..a: 0 0

Mat-200 -s10

S:SENSIBLE HEAT-- 300 - - 15__ __

-- 400" L__ __L_ -20,0 60 70 80 90 100 110 120

AIR "TEMPERATURE. DEGREE F.

Figure 5 B eat Loss frorr Clothed Subjects Doing Light Work.Metabolic Rate = 600 Btu/hr., (30 Btu,/(hr.)(sq.ft.)),S =0

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1400 70

,,oo AIR VELOCITY- 30 FT. MIN. 6

AIR VELOCITY-,OO FT./MIN.

x1000 ,50

B00 REQUIRED LATENT HEAT LOSS /4

Z 600 3C0/ w

20zC

Z•400 20

00

z 200 -20 tw

00 0

U)L0

o _�o6S -200 -10

w

-400 -20

600 SENSIBLE HEAT7G 80 00

0

AIR TEMPERATURE, D'_EGREE F.

Figure 6 -Heat Loss from Nude Supine Resting Subjects. MetabolicRate = 300 Btu/hr., (15 Btu/(hr.)(sq.ft.)), S = 0

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16001- 80

1400 [... - AIR VELOC'TY-30 FT./ MIN. 70,0 •,AIR VELOCiTY-,O FT./ MIN.

1200 ... J60

1 000 /' 50 "

REQUIRED LATENT HEAT LOSS -/S800 40 Im

z /_w wM 600 30xzoC_ 400 200

-: 0

z C

200 1I 0

x LLo 0 06 o

C,)

ZWS-200 -10 I0

C-(I)

o -400 -20 0M0

C.. - 800 ... 30Lir-00 SENSIBLE HEAT-- eN

-8000 -40

w-1000 50__ ___ _ _- ~_ _ _

-1200 - 6060 70 80 90 100 110 120

AIR TEMPERATURE, DEGREE F.

Figure 7 - Heat Loss from Nude Subjects, Seated, at Rest.Metabolic Rate = 400 Btu'hr. , (20 Btu,"(hr. )(sq.ft.)),S=0

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2000 . 100

1800 --- AIR VELOCITY-30+50 = 80 FT./MIN. 90AIR VELOCITY-IO0 +50= 150 FT./MIN.

1600 80

1400 7 70

z1200 6o0REQUIRED LATENT HEAT LOSS 1

1 000 50I io

H -z 800 40 -

Z 600 3030>

• o o

0

wo •O '0, ,,.,z -40 2 0 iO

-1200 10 t-0L-

0

wC-

S-200 -10 V)0 V0

00

S-8400 -SE ,EA -4200 200 -60

-14-00

6j-070 8900010 420

AIR TEMPERATURE, DEGREE F.

Figure 8 -Heat Loss fron' Nudte Subjects Doing Light Work.Metabolic Rate. 600 Btu hr., (30 Btu '( hr. )( sq. ft.)),

S--O-

S.-

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29 31 340 1608 28 30 320

6o6 o 200 27 29 300 140

4 1 026 28 28 30

2- 24 26 120i.6,o 25

too 23 24 240 1108 0 2.2 23 220

, It•- 170 2 29521 222 200 90

165 2012 190 854 1.9

0 20)- ISO so2 W --.8 W 170* l55 -. Io155 -T. 75

,,- -- o V) J 1.7 is I 160 70 V)150 LJ a . W15

10 14 1. 17 40 65~

ix- 1.5 166W 14 mI3 60

z 135 Z U) z. 4 1 50 x-4 •3 11300 U.1.... 0 425

125 41.2 m3 )I90 40~

4- 0'W

x 120 49 8(0 U 1 10 3t~

1 15 W 00

110 I7 00.9

los reg" 9 ~~sBd Srae hr

105 925

4 0.8

2 95 0.7 z

900.6,

DIRECTrIONS

To find the body surface area of a subject draw a linefrom his height (Scale I ) to his weight (Scale 1L) andread area or~ Scale =m

Fifjure 9 -Du Bois Body Surface Chart

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20 F T

I•19ILC,.d

I-c,

I-.

x

L-)

0 f

w 15__ __ __ __ _ __ _

MALEz

V) 1

D 132 3 0 0 6

AGE-YEARS

Figure 10 - Supine Resting Metabol ic Rate vs. Age

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3u. l±Vbld~i 31 sine .L3M0 to 0 in

0 0

0 0 en 0 In 0 In 0 In 0oiIN IN - -

~In

0: In

w - 0

Inc nIn-

00CY 0

xo In w0 i

00

0n 000 in

* on 0

I0 0InC

IXn

In 0 -'

006

In~

a -

In In

Inn

in i

0 W 0 0LL. n 0

40 In 0L Ij 00I 0 40 0 ;inW . In 0n inN -

ZB > ~ ww ItflS3i ind

Page 29: SENSIBLE AND LATENT HEAT LOSSES FROM OCCUPANTS OF … · sensible and latent heat losses from occupants of survival shelters occupational health research and training facility cincinnati,

o l 0 to0 t

0 to 0 I in0 0 0 In 0

4' 0

0*

V N

o cr 0

Inin

00

-- v 0

0' 0

00

0 CY

in 7;w(o

w 0 in In

D 0 0

in 4 a 0

(>.O W t.-S~d (A -100 .A

Page 30: SENSIBLE AND LATENT HEAT LOSSES FROM OCCUPANTS OF … · sensible and latent heat losses from occupants of survival shelters occupational health research and training facility cincinnati,

(A.) 3aJfl1VN3dWi31in 13l8IM0 00' 0 in

o 0P-..

0

0 n 0 n 0 in 0 0no in 0l in CA - -

0 In

In n 40 Co::~

in 0 ený J0 0. 0 0

0 0

x 0 i ly04( C4 0 0

innU00

00

in'0

w 0

G8

z Ien

0 0 n 0 r 0n fnno en 0 e

n p - t

In oW) ~fS3~ OV

Page 31: SENSIBLE AND LATENT HEAT LOSSES FROM OCCUPANTS OF … · sensible and latent heat losses from occupants of survival shelters occupational health research and training facility cincinnati,

UNCLASSIFIED

Security Classification

DOCUMENT CONTROL DATA - R&D(SOcuntV classification ol itile. body at abstract and avpdeuw4 annott~ion must be eflieftd when the @vweal mportof 6 leasoetoed)

I ORItGINATIN 0 ACTIVITY (Couponoe# authot) I. Z CRPORT SECufliy C LASSIVICATrON

U.S. DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE UnclassifiedPUBLIC HEALTH SERVICE, DIV. OF HEALTH, MOBILIZATION 26 smoup,WASHINGTON, D.C. 202011

3 RRPORT TITLE

SENSIBLE AN4D LATENT HEAT WSESES FROM OCCUPANTS OF SURVIVAL SHELTERS

4 09SCRgP1'gV9 NOTES f(7). 01 MPW. MWd IneiS.ve dae*.)

Final Report

6 AuTNOWtS) (Loot flame, host name. initial)

Humphreys, Clark M.Henschel, AustinLee,_DougalasH._K L,_________________

0 REPORTY DATE 70 TOTAL " or OPikers 7 NbO or agora

November 1965 28 Noneto CONTRACT ON 6011696 P40 9e @R.16rnTO1* RofIPN "~or#UmegatS)

OCD-PS-64- 1264PR0J6CT NO, 1200 N

C Task No. 1220 9b OTWIR 01PORT MOMS (Any ot~er ntmsbe Oaft may be eaeag.d

First Editiond. Work Unit 1221C ______________________

10 AVAILABILITY /LIMITATION NOTICES

Distribution of this document is unlimited.

I I SUPPLEWIMNTARY NOTEtS 12 SPONSORING knLITARY ACT1140T'VOffice of Civil Defense (OCD)

None Department of the Army - OSA____________________________Washington,_D._C.__20310

dC01 ABSTRACT

Six figures have been prepared showing the sensible and latent heat exchangerates from clothed and nude individuals at various environmental conditionsand at three metabolic rates. Da-ta are also included by which the heatexchange rates for the "standard individual" may be corrected for"non-standard" groups.

FOS U 47 LCLASSIFIED

Security Classificabo-a

Page 32: SENSIBLE AND LATENT HEAT LOSSES FROM OCCUPANTS OF … · sensible and latent heat losses from occupants of survival shelters occupational health research and training facility cincinnati,

U C T

C.,_ss fI(t ron14

Sensible and Latent Heat Exchange Rates,Environmentla Conditions, Metabolic Rates,Survival Shelters, Shelter Occupants

INSTRUCTIONS

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