Appendix 1 | 929

Prep

ared

by

Cen

ter

for A

pplie

d T

herm

odyn

amic

Stu

dies

, Uni

vers

ity o

f Id

aho.

1.0

0.95

0.90

0.85

0.80

0.75

0.70

0.65

0.60

0.55

0.50

0.45

0.40

0.36

Ent

halp

y—

——

——

—H

umid

ity r

atio

Δh —— Δ�

=

Sensible heat —————–Total heat

ΔHS——ΔHT

=

60

5040

3020

Dry

bul

b te

mpe

ratu

re °C

100

708090100

110

120

Sens

ible

hea

t—

——

——

–To

tal h

eat

ΔHS

——

ΔHT

=

1.0

–•

–5.

0–

2.0

0.0

1.0

2.0

2.5

3.0

4.0

5.0

10.0•

0.1

0.2

0.3

0.4

0.5

0.6

0.8

0.7

1.0

1.5

2.0

4.0

–4.0

–2.0

–1.0

–0.5

–0.2

•

0

Enthalp

y (h)

kiloj

oules

per k

ilogr

am dr

y air

20

30

40

50

60

70

80

90

100

Saturat

ion te

mperat

ure °

C

5

10

15

20

25

30

30

0.94

30

20

15

10

5

0

0.90

0.88

0.86

0.84

0.82

0.80

0.78

28

90%80%

70%

60%

50%

40%

30%

20%

26 24 22 20 18 16 14 12 10 8

10%

rel

ativ

e hu

mid

ity

25 w

et b

ulb

tem

pera

ture

°C

0.92 volume cubic meter per kilogram dry air

Humidity ratio (�) grams moisture per kilogram dry air

6 4 2

ASH

RA

E P

sych

rom

etri

c C

hart

No.

1N

orm

al T

empe

ratu

reB

arom

etri

c Pr

essu

re: 1

01.3

25 k

Pa

©19

92 A

mer

ican

Soc

iety

of

Hea

ting,

R

efri

gera

ting

and

Air

-Con

ditio

ning

Eng

inee

rs, I

nc.

Sea

Lev

el

FIGU

RE A

–31

Psyc

hrom

etri

c ch

art a

t 1 a

tm to

tal p

ress

ure.

Rep

rint

ed b

y pe

rmis

sion

of t

he A

mer

ican

Soc

iety

of H

eati

ng,R

efri

gera

ting

and

Air

-Con

diti

onin

g E

ngin

eers

,Inc

.,A

tlan

ta,G

A;

used

wit

h pe

rmis

sion

.

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