PSYCHROMETRICS 101 NATIONAL CAPITAL CHAPTER ASHRAE WEDNESDAY, OCTOBER 7, 2015
Jesse Fisher, PE [email protected] What is psychrometrics?
The field of engineering concerned with the determination of physical and thermodynamic properties of gas-vapor mixtures. Dry Air Water Vapor
• Mixture of gases. • Heat of Vaporization is
• 78% Nitrogen approximately 1000
• 21% Oxygen BTU/lbm • Standard Temp = 59°F • Maximum amount of water in dry air is • Standard Press = 14.7 psi function of temperature • Sensible Heat and pressure. • Saturation is the point of equilibrium between moist air and the condensed water phase. • Latent Heat HVAC PSYCHROMETRICS The Psychrometric Chart HVAC Psychrometrics Psychrometric Chart 55 0.20 0.25 0.30 SENSIBLE HEAT RATIO = Qs / Qt
0.35 90 5 0 200 1.30
1 4 1.25 . 190 6 1 1 85 4 5 . . 85 8 0 1.20 180 0.40
e r 45 1.15 tu is o 170 m BAROMETRIC PRESSURE: 29.921 in. HG d 1.10 te 1 a 4 i . c 4 55 o s s F 160 1.05 a ° 0.45 d - 80 n E 80 a r R i U a T 1.00 y r A 150 d 40 R f E o P R . I M lb A E 0.95 r 1 0.50
T Y e 4 WE p B . T R L 2 B 140 u U D t U LB B B T F - E 0.90
T M O P Y E E
P 75 R D W AT 75 5 L U N 0 A R 130 0.55 U E e H - r ° O 0.85
T F u t N P
s E i
3 R 5 o Y E m R
P 0.80 1 4 120 d 0.60 U E e C
. t 0 R F a R i ° U c E - T
o M
S E s 0.75
70 I s F 70 R O a 0.65
% 110 O U
0 M d T 9 S n F A E a
R 3 O 0.70 r
0 H
i E a S C
0.70 1 P N y N I I
4 r
3 M 100 5 - d . A E
8
f 0.65
% R T E
0 o
8 G 0.75 . R T
) 65 b U N l
y 65 I t r S i O e S d i
90 P 0.60 p 0.80 E
m u 2 R t u 5 W P B E H
%
0 - 0.85 D R
1 7 c i
3 f Y O . i 0.55 c 6 P 80 0.90 P e L
60 A p A
60 V S H
r 0.95
T 0.50 o ( N 0% 6 E 1.00 O 2 70 I t 0 T 4 1 0 A
3 Q 0.45
55 . R / 4 55 Y s T I % Q
0 60 D 0.40 5 I =
M U O 50 1 I H
3 50 T 1 . 0.35 5 2 50 A R 0% 45 4 T 45 A 0.30
1 E 3 . H 0 40 40 E 0% 40 35 L 0.25 3 B 1 I
2 S 35 . 8 30 35 N 0.20 32 E S 1 10 30 2 . 0% 30 6 2 0.15 20 25 IDITY 20 0.10 25 TIVE HUM 10% RELA 10 10 0.05 0 30 20 0 30 40 50 60 STANDARD AIR 70 80 90 100 110 115 DRY BULB TEMPERATURE - °F Chart by: HANDS DOWN SOFTWARE, www.handsdownsoftware.com
10 15 20 25 ENTHALPY - Btu per lb. of dry air and associated moisture HVAC Psychrometrics Psychrometric Properties Psychrometric Properties of Air
• Dry Bulb Temperature • Wet Bulb Temperature • Dew Point Temperature • Relative Humidity • Humidity Ratio Dry Bulb Temperature (DBT) 55 0.20 0.25 0.30 • Units: °F SENSIBLE HEAT RATIO = Qs / Qt
0.35 90 • T: Absolute temperature (R or K) 5 0 200 1.30
1 4 1.25 . 190 • t: Relative Temperature (F or C) 6 1 1 85 4 5 . . 85 8 0 1.20 180 0.40
e - r 45 1.15 tu is o 170 m BAROMETRIC PRESSURE: 29.921 in. HG d 1.10 te 1 a 4 i . c 4 55 o s s F 160 1.05 a ° 0.45 d - 80 n E 80 a r R i U a T 1.00 y r A 150 d 40 R f E o P R . I M lb A E 0.95 r 1 0.50
T Y e 4 WE p B . T R L 2 B 140 u U D t U LB B B T F - E 0.90
T M O P Y E E
P 75 R D W AT 75 5 L U N 0 A R 130 0.55 U E e H - r ° O 0.85
T F u t N P
s E i
3 R 5 o Y E m R
P 0.80 1 4 120 d 0.60 U E e C
. t 0 R F a R i ° U c E - T
o M
S E s 0.75
70 I s F 70 R O a 0.65
% 110 O U
0 M d T 9 S n F A E a
R 3 O 0.70 r
0 H
i E a S C
0.70 1 P N y N I I
4 r
3 M 100 5 - d . A E
8
f 0.65
% R T E
0 o
8 G 0.75 . R T
) 65 b U N l
y 65 I t r S i O e S d i
90 P 0.60 p 0.80 E
m u 2 R t u 5 W P B E H
%
0 - 0.85 D R
1 7 c i
3 f Y O . i 0.55 c 6 P 80 0.90 P e L
60 A p A
60 V S H
r 0.95
T 0.50 o ( N 0% 6 E 1.00 O 2 70 I t 0 T 4 1 0 A
3 Q 0.45
55 . R / 4 55 Y s T I % Q
0 60 D 0.40 5 I =
M U O 50 1 I H
3 50 T 1 . 0.35 5 2 50 A R 0% 45 4 T Dry Bulb Temperature 45 A 0.30
1 E 3 . H 0 40 40 E 0% 40 35 L 0.25 3 B 1 I
2 S 35 . 8 30 35 N 0.20 32 E S 1 10 30 2 . 0% 30 6 2 0.15 20 25 IDITY 20 0.10 25 TIVE HUM 10% RELA 10 10 0.05 0 30 20 0 30 40 50 60 STANDARD AIR 70 80 90 100 110 115 DRY BULB TEMPERATURE - °F Chart by: HANDS DOWN SOFTWARE, www.handsdownsoftware.com 10 Dry Bulb15 Temperature;20 °F 25 ENTHALPY - Btu per lb. of dry air and associated moisture Wet Bulb Temperature (DBT) 55 0.20 0.25 0.30 • NOT adiabatic saturation temp. SENSIBLE HEAT RATIO = Qs / Qt
0.35 90 • Units: °F 5 0 200 1.30
1 4 1.25 . 190 6 1 1 85 4 5 . . 85 8 0 1.20 180 0.40
e r 45 1.15 tu is o 170 m BAROMETRIC PRESSURE: 29.921 in. HG d 1.10 te 1 a 4 i . c 4 55 o s s F 160 1.05 a ° 0.45 d - 80 n E 80 a r R i U a T 1.00 y r A 150 d 40 R f E o P R . I M lb A E 0.95 r 1 0.50
T Y e 4 WE p B . T R L 2 B 140 u U D t U LB B B T F - E 0.90
T M O P Y E E
P 75 R D W AT 75 5 L U N 0 A R 130 0.55 U E e H - r ° O 0.85
T F u t N P
s E i
3 R 5 o Y E m R
P 0.80 1 4 120 d 0.60 U E e C
. t 0 R F a R i ° U c E - T
o M
S E s 0.75
70 I s F 70 R O a 0.65
% 110 O U
0 M d T 9 S n F A E a
R 3 O 0.70 r
0 H
i E a S C
0.70 1 P N y N I I
4 r
3 M 100 5 - d . A E
8
f 0.65
% R T E
Wet Bulb Temperature0 o
8 G 0.75 . R T
) 65 b U N l
y 65 I t r S i O e S d i
90 P 0.60 p 0.80 E
m u 2 R t u 5 W P B E H
%
0 - 0.85 D R
1 7 c i
3 f Y O . i 0.55 c 6 P 80 0.90 P e L
60 A p A
60 V S H
r 0.95
T 0.50 o ( N 0% 6 E 1.00 O 2 70 I t 0 T 4 1 0 A
3 Q 0.45
55 . R / 4 55 Y s T I % Q
0 60 D 0.40 5 I =
M U O 50 1 I H
3 50 T 1 . 0.35 5 2 50 A R 0% 45 4 T 45 A 0.30
1 E 3 . H 0 40 40 E 0% 40 35 L 0.25 3 B 1 I
2 S 35 . 8 30 35 N 0.20 32 E S 1 30 1 0 2 - . 0% 30 6 2 0.15 20 25 IDITY 20 0.10 25 TIVE HUM 10% RELA 10 10 0.05 0 30 20 0 30 40 50 60 STANDARD AIR 70 80 90 100 110 115 DRY BULB TEMPERATURE - °F Chart by: HANDS DOWN SOFTWARE, www.handsdownsoftware.com
10 15 20 25 ENTHALPY - Btu per lb. of dry air and associated moisture Dew Point Temperature (DPT or DP) 55 0.20 0.25 0.30 • Temperature when condensation SENSIBLE HEAT RATIO = Qs / Qt
0.35 90 occurs. 5 0 200 1.30
1 4 1.25 . 190 • Units: °F 6 1 1 85 4 5 . . 85 8 0 1.20 180 0.40
e r 45 1.15 tu is o 170 m BAROMETRIC PRESSURE: 29.921 in. HG d 1.10 te 1 a 4 i . c 4 55 o s s F 160 1.05 a ° 0.45 d - 80 n E 80 a r R i U a T 1.00 y r A 150 d 40 R f E o F P R . I M lb A
0.95
E ° r 1 0.50 e T 4 W Y
E p B . T R L 2 B 140 u U D ; t U LB B B T F - E 0.90
T M O P Y E E e
P 75 R D W AT 75 5 L U N 0 A R 0.55 130 r U E e H - r ° O 0.85
T F u t N P
s E i u
3 R 5 o Y E m R
P t 0.80 1 4 120 d 0.60 U E e C
. t 0 R F a R i ° a U c E - T
o M
S E s 0.75 r
70 I s F 70 R O a 0.65
% 110 O U
0 M d T 9 S e n F A E a
R 3 O 0.70 r
0 H
i E a S C
0.70 P 1 p N y N I I
4 r
3 M 100 5 - d . A E
8
f 0.65
% R T E
Dew Point Temperature0 - o
8 G 0.75 . R T
) 65 b U N l m y 65 I t r S i O e S d i
90 P 0.60 p 0.80 E
m e u 2 R t u 5 W P B E H
%
0 - 0.85 D R T 1 7 c i
3 f Y O i 0.55
. c 6 P 80 0.90 P e L
60 A p t A
60 V S H
r 0.95
T 0.50 o ( N
% 0 n 6 E 1.00 O I 2 70 i t 0 T 4 1 0 A
3 Q 0.45
55 . R / 4
55 o Y s T I % Q
0 60 D 0.40 I
5 P =
M
U O 50 1 I H
3 50 T 1 . 0.35 5 2 A
50 w R 0% 45 4 T A 45 e 0.30
1 E 3 . H 0 40 E
40 D 0% 40 35 L 0.25 3 B 1 I
2 S 35 . 8 30 35 N 0.20 32 E S 1 10 30 2 . 0% 30 6 2 0.15 20 25 IDITY 20 0.10 25 TIVE HUM 10% RELA 10 10 0.05 0 30 20 0 30 40 50 60 STANDARD AIR 70 80 90 100 110 115 DRY BULB TEMPERATURE - °F Chart by: HANDS DOWN SOFTWARE, www.handsdownsoftware.com
10 15 20 25 ENTHALPY - Btu per lb. of dry air and associated moisture Relative Humidity (RH) 55 0.20 0.25 0.30 • Unit less measure SENSIBLE HEAT RATIO = Qs / Qt
0.35 90 50% • Ratio of W / W 5 S 0 200 1.30
1 4 1.25 . 190 6 1 1 85 4 5 . . 85 8 0 1.20 180 0.40
e r 45 1.15 tu is o 170 m BAROMETRIC PRESSURE: 29.921 in. HG d 1.10 te 1 a 4 i . c 4 55 o s s F 160 1.05 a ° 0.45 d - 80 n E 80 a r R i U a T 1.00 y r A 50% 150 d 40 R f E o P R . I M lb A E 0.95 r 1 0.50
T Y e 4 WE p B . T R L 2 B 140 u U D t U LB B B T F - E 0.90
T M O P Y E E
P 75 R D W AT 75 5 L U N 0 A R 130 0.55 U E e H - r ° O 0.85
T F u t N P
s E i
3 R 5 o Y E m R
P 0.80 1 4 120 d 0.60 U E e C
. t 0 R F a R i ° U c E - T
o M
S E s 0.75
70 I s F 70 R O a 0.65
50%
% 110 O U
0 M d T 9 S n F A E a
R 3 O 0.70 r
0 H
i E a S C
0.70 1 P N y N I I
4 r
3 M 100 5 - d . A E
8
f 0.65
% R T E
0 o
8 G 0.75 . R T
) 65 b U N l
y 65 I t r S i O e S d i
90 P 0.60 p 0.80 E
m u 2 R t u 5 W P B E H
%
0 - 0.85 D R
1 7 c i
3 f Y O . i 0.55 c 6 P 50% 80 0.90 P e L
60 A p A
60 V S H
r 0.95
T 0.50 o ( N 0% 6 E 1.00 O 2 70 I t 0 T 4 1 0 A
3 Q 0.45
55 . R / 4 55 Y s T I % Q
0 60 D 0.40 5 I =
50% M U O 50 1 I H
3 50 T 1 . 0.35 5 2 50 A R 0% 45 4 T 45 A 0.30
1 E 3 50% . H 0 40 40 E 0% 40 35 L 0.25 3 B 1 I
2 S 35 . 8 50% 30 35 N 0.20 32 E S 1 10 30 2 . 20% 30 6 50% 0.15 20 25 50% IDITY 20 0.10 25 TIVE HUM 10% RELA 10 10 0.05 0 30 20 0 30 40 50 60 STANDARD AIR 70 80 90 100 110 115 DRY BULB TEMPERATURE - °F Chart by: HANDS DOWN SOFTWARE, www.handsdownsoftware.com
10 15 20 25 ENTHALPY - Btu per lb. of dry air and associated moisture Humidity Ratio 55 0.20 0.25 0.30 • Mass Ratio: Water Vapor to Air SENSIBLE HEAT RATIO = Qs / Qt
0.35 90 • Units: grains / lbm or lbm / lbm 5 0 200 1.30
1 4 1.25 . 190 • W: Humidity Ratio 6 1 1 85 4 5 . . 85 8 0 1.20 • WS: Saturated Humidity Ratio 180 0.40 e r 45 1.15 tu is o 170 m BAROMETRIC PRESSURE: 29.921 in. HG d 1.10 te 1 a 4 i . c 4 55 o s s F 160 1.05 a ° 0.45 d - 80 n E 80 a r R m i U a T 1.00 y r 4 A 150 d 0 R b f E
o l P R . I M lb A
0.95 E / r 1 0.50
T Y e 4 WE p B . T R L 2 B 140 u U D t U LB B B T F - E 0.90
M O T m P Y E E
P 75 R D W AT 75 5 L U N 0 A R 130 0.55 U E b e H - r ° O 0.85
T F u l t N P
s E i
3 R 5 o Y E m - R
P 0.80 1 4 120 d 0.60 U E e C t . r 0 R F a R i ° U c E - T
o M
S E s 0.75 o
70 I s F 70 R O a 0.65
% 110 O U
0 M d T 9 – S n F A E a
R 3 O 0.70 r
0 H
i E a S C
0.70 1 P N y N I I
4 r
3 M 100 5 - d . A E
8
f 0.65
% R T m E
0 o
8 G 0.75 . R T
) 65 b U N l
y 65 I t r S i b O e S d i
90 P 0.60 p 0.80 E l
m u 2 R t u 5 W P / B E H
%
0 - 0.85 D R
1 7 c i
3 f Y r O . i 0.55 c 6 P 80 0.90 P e L
60 A p A
Humidity Ratio - 60 V g S H
r 0.95 T 0.50 o ( N
% 0 ; 6 E 1.00 O 2 70 I t 0 T 4 1 0 A Q 3 o 0.45
55 . R / 4
i 55 Y s T I t % Q
0 60 D 0.40 5 I =
M a U O 50 1 I H
3 50 T 1 . 0.35 5 2 A 50 R R
0% 45 4 T 45 A 0.30 y 1 E 3 . H
0 40 t E
40 i 0% 40 35 L 0.25 3 B 1 I S
2 d 35 . 8 N 30 i 35 0.20 32 E S 1 10 30 2 . 0% 30 6 2 0.15 m 20 25
IDITY u 20 0.10 25 TIVE HUM 10% RELA 10 H 10 0.05 0 30 20 0 30 40 50 60 STANDARD AIR 70 80 90 100 110 115 DRY BULB TEMPERATURE - °F Chart by: HANDS DOWN SOFTWARE, www.handsdownsoftware.com
10 15 20 25 ENTHALPY - Btu per lb. of dry air and associated moisture HVAC Psychrometrics “Other” Properties Enthalpy (BTU/lbm) 55 0.20 0.25 0.30 • Total Energy; adiabatic saturation SENSIBLE HEAT RATIO = Qs / Qt
0.35 90 temperature. 5 0 200 1.30
1 4 1.25 . 190 • H = Sen + Lat 6 1 1 85 4 5 . . 85 8 0 1.20 • Lines are parallel 180 0.40 e r 45 1.15 tu is o 170 m BAROMETRIC PRESSURE: 29.921 in. HG d 1.10 te 1 a 4 i . c 4 55 o s s F 160 1.05 a ° 0.45 d - 80 n E 80 a r R i U a T 1.00 y r A 150 d 40 R f E o P R . I M lb A E 0.95 r 1 0.50
T Y e 4 WE p B . T R L 2 B 140 u U D t U LB B B T F - E 0.90
T M O P Y E E
P 75 R D W AT 75 5 L U N 0 A R 130 0.55 U E e H - r ° O 0.85
T F u t N P
s E i
3 R 5 o Y E m R
P 0.80 1 4 120 d 0.60 U E e C
. t 0 R F a R i ° U c E - T Enthalpy o M
S E s 0.75
70 I s F 70 R O a 0.65
% 110 O U
0 M d T 9 S n F A E a
R 3 O 0.70 r
0 H
i E a S C
0.70 1 P N y N I I
4 r
3 M 100 5 - d . A E
8
f 0.65
% R T E
0 o
8 G 0.75 . R T
) 65 b U N l
y 65 I t r S i O e S d i
90 P 0.60 p 0.80 E
m u 2 R t u 5 W P B E H
%
0 - 0.85 D R
1 7 c i
3 f Y O . i 0.55 c 6 P 80 0.90 P e L
60 A p A
60 V S H
r 0.95
T 0.50 o ( N 0% 6 E 1.00 O 2 70 I t 0 T 4 1 0 A
3 Q 0.45
55 . R / 4 55 Y s T I % Q
0 60 D 0.40 5 I =
M U O 50 1 I H
3 50 T 1 . - 0.35 5 2 50 A R 0% 45 4 T 45 A 0.30
1 E 3 . H 0 40 40 E 0% 40 35 L 0.25 3 B 1 I
2 S 35 . 8 30 35 N 0.20 32 E S 1 10 30 2 . 0% 30 6 2 0.15 20 25 IDITY 20 0.10 25 TIVE HUM 10% RELA 10 10 0.05 0 30 20 0 30 40 50 60 STANDARD AIR 70 80 90 100 110 115 DRY BULB TEMPERATURE - °F Chart by: HANDS DOWN SOFTWARE, www.handsdownsoftware.com
10 15 20 25 ENTHALPY - Btu per lb. of dry air and associated moisture Specific Volume 55 0.20 0.25 0.30 • Cubic Feet Air / Pound Mass SENSIBLE HEAT RATIO = Qs / Qt
0.35 90 • Measure of Density 5 0 200 1.30
1 4 1.25 . 190 6 1 1 85 4 5 . . 85 8 0 1.20 180 0.40
e r 45 1.15 tu is o 170 m BAROMETRIC PRESSURE: 29.921 in. HG d 1.10 te 1 a 4 i . c 4 55 o s s F 160 1.05 a ° 0.45 d - 80 n E 80 a r R i U a T 1.00 y r A 150 d 40 R f E o P R . I M lb A E 0.95 r 1 0.50
T Y e 4 WE p B . T R L 2 B 140 u U D t U LB B B T F - E 0.90
T M O P Y E E
P 75 R D W AT 75 5 L U N 0 A R 130 0.55 U E e H - r ° O 0.85
T F u t N P
s E i
3 R 5 o Y E m R
P 0.80 1 4 120 d 0.60 U E e C
. t 0 R F a R i ° U c E - T
o M
S E s 0.75
70 I s F 70 R O a 0.65
% 110 O U
0 M d T 9 S n F A E a
R 3 O 0.70 r
0 H
i E a S C
Specific Volume 0.70 1 P N y N I I
4 r
3 M 100 5 - d . A E
8
f 0.65
% R T E
0 o
8 G 0.75 . R T
) 65 b U N l
y 65 I t r S i O e S d i
90 P 0.60 p 0.80 E
m u 2 R t u 5 W P B E H
%
0 - 0.85 D R
1 7 c i
3 f Y O . i 0.55 c 6 P 80 0.90 P e L
60 A p A
60 V S H
r 0.95
T 0.50 o ( N 0% 6 E 1.00 O 2 70 I t 0 T 4 1 0 A
3 Q 0.45
55 . R / 4 55 Y s T I % Q
0 60 D 0.40 5 I =
M U O 50 1 I H
3 50 T 1 . 0.35 5 2 50 A R 0% 45 4 T 45 A 0.30
1 E 3 . H 0 40 40 E 0% 40 35 L 0.25 3 B 1 I
2 S 35 . 8 30 35 N 0.20 32 E S 1 10 30 2 . 0% 30 6 2 0.15 20 25 IDITY 20 0.10 25 TIVE HUM 10% RELA 10 - 10 0.05 0 30 20 0 30 40 50 60 STANDARD AIR 70 80 90 100 110 115 DRY BULB TEMPERATURE - °F Chart by: HANDS DOWN SOFTWARE, www.handsdownsoftware.com
10 15 20 25 ENTHALPY - Btu per lb. of dry air and associated moisture Sensible Heat Ratio 55 0.20 0.25 0.30 SENSIBLE HEAT RATIO = Qs / Qt • Defines the slop for the space Sensible Heat Ratio 0.35 90 being served 5 0 200 1.30
1 4 1.25 . 190 • Q /Q 6 S T 1 1 85 4 5 . . 85 8 0 1.20 180 0.40
e r 45 1.15 tu is o 170 m BAROMETRIC PRESSURE: 29.921 in. HG d 1.10 te 1 a 4 i . c 4 55 o s s F 160 1.05 a ° 0.45 d - 80 n E 80 a r R i U a T 1.00 y r A 150 d 40 R f E o P R . I M
b A
l o E 0.95 r 1 0.50 T 4 W Y e E i p B . T R L 2 B 140 u U D t U LB t B B T F - E 0.90
T M O P Y E E a P 75 R D W AT 75 5 L U N 0 A R 130 0.55 U E e H - r ° O 0.85 R
T F u t N P
s
E i
3 R 5 o Y E t m R
P 0.80 1 4 120 d 0.60 U E e C
. t 0 R F a a R i ° U c E - T
o M
S E s 0.75
70 I e s F 70 R O a 0.65
% 110 O U
0 M d T 9 S n F A E a
H R 3 O 0.70 r
0 H
i E a S C
0.70 1 P N y N I I
4 r
3 M 100 5 - d . A E
8
f 0.65 e
% R T E
0 o
8 G 0.75 . l R T
) 65 b U N l
y 65 I t r S i O e S d i
90 P 0.60 b p 0.80 E
m u R
2 i t u 5 W P B E H
%
0 - 0.85 D R
1 7 c i s
3 f Y O . i 0.55 c 6 SHR = 0.6 P 80 0.90 P e L
60 A p A V
60 n S H
r 0.95
T 0.50 o ( N
% 0 e 6 E 1.00 O 2 70 I t 0 T 4 1 0 A S 3 Q 0.45
55 . R / 4 55 Y s T I % Q
- 0 SHR = 1.0 60 D 0.40 5 I =
M U O 50 1 I H
3 50 T 1 . 0.35 5 2 50 A R 0% 45 4 T 45 A 0.30
1 E 3 . H 0 40 40 E 0% 40 35 L 0.25 3 B 1 I
2 S 35 . 8 30 35 N 0.20 32 E S 1 10 30 2 . 0% 30 6 2 0.15 20 25 IDITY 20 0.10 25 TIVE HUM 10% RELA 10 10 0.05 0 30 20 0 30 40 50 60 STANDARD AIR 70 80 90 100 110 115 DRY BULB TEMPERATURE - °F Chart by: HANDS DOWN SOFTWARE, www.handsdownsoftware.com
10 15 20 25 ENTHALPY - Btu per lb. of dry air and associated moisture HVAC Psychrometrics Determining State Points Determining State Points 55 0.20 0.25 0.30 • Any condition can be fixed SENSIBLE HEAT RATIO = Qs / Qt
0.35 90 on the chart with just two 5 0 200 1.30
1 4 1.25 . 190 properties. 6 1 1 85 4 5 . . 85 8 0 1.20 • Every property can be 180 0.40 e r 45 1.15 tu is o 170 m determinedBAROMETRIC PRESSURE: 29.921 once in. HG the state d 1.10 te 1 a 4 i . c 4 55 o s s F 160 1.05 a ° 0.45 d - 80 point is fixed on the chart. n E 80 a r R i U a T 1.00 y r A 150 d 40 R f E o P R . I M lb A E 0.95 r 1 0.50
T Y e 4 WE p B . T R L 2 B 140 u U D t U LB B B T F - E 0.90
T M O P Y E E
P 75 R D W AT 75 5 L U N 0 A R 130 0.55 U E e H - r ° O 0.85
T F u t N P
s E i
3 R 5 o Y E m R
Outdoor Air: 95 DBT / 78 WBT P 0.80 1 4 120 d 0.60 U E e C
. t 0 R F a R i ° U c E - T
o M
S E s 0.75
70 I s F 70 R O a 0.65
% 110 O U
0 M d T 9 S n F A E a
R 3 O 0.70 r
0 H
i E a S C
0.70 1 P N y N I I
4 r
3 M 100 5 - d . A E
8
f 0.65
% R T E
0 o
8 G 0.75 . R T
) 65 b U N l
y 65 I t r S i O e S d i
90 P 0.60 p 0.80 E
m u 2 R t u 5 W P B E H
%
0 - 0.85 D R
1 7 c i
3 f Y O . i 0.55 c 6 P 80 0.90 P e L
60 A p A
60 V S H
r 0.95
T 0.50 o ( N 0% 6 E 1.00 O 2 70 I t 0 Return Air: 75 DBT & 50% RH T 40 1 A
3 Q 0.45
55 . R / 4 55 Y s T I % Q
0 60 D 0.40 5 I =
M U O 50 1 I H
3 50 T 1 . 0.35 5 2 50 A R 0% 45 4 T 45 A 0.30
1 E 3 . H 0 40 40 E 0% 40 35 L 0.25 3 B 1 I
2 S 35 . 8 30 35 N 0.20 32 E S 1 10 30 2 . 0% 30 6 2 0.15 20 25 IDITY 20 0.10 25 TIVE HUM 10% RELA 10 10 0.05 0 30 20 0 30 40 50 60 STANDARD AIR 70 80 90 100 110 115 DRY BULB TEMPERATURE - °F Chart by: HANDS DOWN SOFTWARE, www.handsdownsoftware.com
10 15 20 25 ENTHALPY - Btu per lb. of dry air and associated moisture HVAC PSYCHROMETRICS Psychrometric Processes Mixing 55 0.20 0.25 0.30 • Process line connection the two SENSIBLE HEAT RATIO = Qs / Qt
0.35 90 state points being mixed. 5 0 200 1.30
1 4 1.25 . 190 • Mixed state point is 6 1 1 85 4 5 . . 85 8 0 1.20 proportionally along the mixing 180 0.40 e r 45 1.15 tu is o 170 m line.BAROMETRIC PRESSURE: 29.921 in. HG d 1.10 te 1 a 4 i . c 4 55 o s s F 160 1.05 a ° 0.45 d - 80 n E 80 a r R i U a T 1.00 y r A 150 d 40 R f E o P R . I M lb A E 0.95 r 1 0.50
T Y e 4 WE p B . T R L 2 B 140 u U D t U LB B B T F - E 0.90
T M O P Y E E
P 75 R D W AT 75 5 L U N 0 A R 130 0.55 U E e H - r ° O 0.85
T F u t N P
s E i
3 R 5 o Y E m R
Outdoor Air P 0.80 1 4 120 d 0.60 U E e C
. t 0 R F a R i ° U c E - T
o M
S E s 0.75
70 I s F 70 R O a 0.65
% 110 O U
0 M d T 9 S n F A E a
R 3 O 0.70 r
0 H
i E a S C
0.70 1 P N y N I I
4 r
3 M 100 5 - d . A E
8
f 0.65
% R T E
0 o
8 G 0.75 . R T
) 65 b U N l
y 65 I t r S i O e S d i
90 P 0.60 p 0.80 E
m u 2 R t u 5 W P B E H
%
0 - 0.85 D R
1 7 c i
3 f Y O i 0.55 . Mixed Air: 25% OA c 6 P 80 0.90 P e L
60 A p A
60 V S H
r 0.95
T 0.50 o ( N 0% 6 E 1.00 O 2 70 I t 0 Return Air T 40 1 A
3 Q 0.45
55 . R / 4 55 Y s T I % Q
0 60 D 0.40 5 I =
M U O 50 1 I H
3 50 T 1 . 0.35 5 2 50 A R 0% 45 4 T 45 A 0.30
1 E 3 . H 0 40 40 E 0% 40 35 L 0.25 3 B 1 I
2 S 35 . 8 30 35 N 0.20 32 E S 1 10 30 2 . 0% 30 6 2 0.15 20 25 IDITY 20 0.10 25 TIVE HUM 10% RELA 10 10 0.05 0 30 20 0 30 40 50 60 STANDARD AIR 70 80 90 100 110 115 DRY BULB TEMPERATURE - °F Chart by: HANDS DOWN SOFTWARE, www.handsdownsoftware.com
10 15 20 25 ENTHALPY - Btu per lb. of dry air and associated moisture Heating 55 0.20 0.25 0.30 • Q=1.08 x CFM x Delta T SENSIBLE HEAT RATIO = Qs / Qt
0.35 90 • Sensible Only Process 5 0 200 1.30
1 4 1.25 . 190 6 1 1 85 4 5 . . 85 8 0 1.20 180 0.40
e r 45 1.15 tu is o 170 m BAROMETRIC PRESSURE: 29.921 in. HG d 1.10 te 1 a 4 i . c 4 55 o s s F 160 1.05 a ° 0.45 d - 80 n E 80 a r R i U a T 1.00 y r A 150 d 40 R f E o P R . I M lb A E 0.95 r 1 0.50
T Y e 4 WE p B . T R L 2 B 140 u U D t U LB B B T F - E 0.90
T M O P Y E E
P 75 R D W AT 75 5 L U N 0 A R 130 0.55 U E e H - r ° O 0.85
T F u t N P
s E i
3 R 5 o Y E m R
P 0.80 1 4 120 d 0.60 U E e C
. t 0 R F a R i ° U c E - T
o M
S E s 0.75
70 I s F 70 R O a 0.65
% 110 O U
0 M d T 9 S n F A E a
R 3 O 0.70 r
0 H
i E a S C
0.70 1 P N y N I I
4 r
3 M 100 5 - d . A E
8
f 0.65
% R T E
0 o
8 G 0.75 . R T
) 65 b U N l
y 65 I t r S i O e S d i
90 P 0.60 p 0.80 E
m u 2 R t u 5 W P B E H
%
0 - 0.85 D R
1 7 c i
3 f Y O . i 0.55 c 6 P 80 0.90 P e L
60 A p A
60 V S H
r 0.95
T 0.50 o ( N 0% 6 E 1.00 O 2 70 I t 0 T 4 1 0 A
3 Q 0.45
55 . R / 4 55 Y s T I % Q
0 60 D 0.40 5 I =
M U O 50 1 I H
3 50 T 1 . 0.35 5 2 50 A R 0% 45 4 T 45 A 0.30
1 E 3 Mixed Winter Air Heating Supply Air . H 0 40 40 E 0% 40 35 L 0.25 3 B 1 I
2 S 35 . 8 30 35 N 0.20 32 E S 1 10 30 2 . 0% 30 6 2 0.15 20 25 IDITY 20 0.10 25 TIVE HUM 10% RELA 10 10 0.05 0 30 20 0 30 40 50 60 STANDARD AIR 70 80 90 100 110 115 DRY BULB TEMPERATURE - °F Chart by: HANDS DOWN SOFTWARE, www.handsdownsoftware.com
10 15 20 25 ENTHALPY - Btu per lb. of dry air and associated moisture Cooling 55 0.20 0.25 0.30 SENSIBLE HEAT RATIO = Qs / Qt • QSEN=1.08 x CFM x Delta T 0.35 90 • Q =4.45 X CFM x Delta h 5 TOTAL 0 200 1.30
1 4 1.25 . 190 • Cooling is sensible only until the 6 1 1 85 4 5 . . 85 8 0 1.20 air is cooled below the DPT. 180 0.40 e r 45 1.15 tu is o 170 m BAROMETRIC PRESSURE: 29.921 in. HG d 1.10 te 1 a 4 i . c 4 55 o s s F 160 1.05 a ° 0.45 d - 80 n E 80 a r R i U a T 1.00 y r A 150 d 40 R f E o P R . I M lb A E 0.95 r 1 0.50
T Y e 4 WE p B . T R L 2 B 140 u U D t U LB B B T F - E 0.90
T M O P Y E E
P 75 R D W AT 75 5 L U N 0 A R 130 0.55 U E e H - r ° O 0.85
T F u t N P
s E i
3 R 5 o Y E m R
P 0.80 1 4 120 d 0.60 U E e C
. t 0 R F a R i ° U c E - T
o M
S E s 0.75
70 I s F 70 R O a 0.65
% 110 O U
0 M d T 9 S n F A E a
R 3 O 0.70 r
0 H
i E a S C
0.70 1 P N y N I I
4 r
3 M 100 5 - d . A E
8
f 0.65
% R T E
0 o
8 G 0.75 . R T
) 65 b U N l
y 65 I t r S i O e S d i
90 P 0.60 p 0.80 E
m u 2 R t u 5 W P B E H
%
0 - 0.85 D R
1 7 c i
3 f Y O Summer Mixed Air i . 0.55 c 6 P 80 0.90 P e L
60 A p A
60 V S H
r 0.95
T 0.50 o ( N 0% 6 E 1.00 O 2 70 I t 0 T 4 1 0 A
3 Q 0.45
55 . R / 4 55 Y s T I % Q
0 60 D 0.40 Leaving Cooling Coil 5 I =
M U O 50 1 I H
3 50 T 1 . 0.35 5 2 50 A R 0% 45 4 T 45 A 0.30
1 E 3 . H 0 40 40 E 0% 40 35 L 0.25 3 B 1 I
2 S 35 . 8 30 35 N 0.20 32 E S 1 10 30 2 . 0% 30 6 2 0.15 20 25 IDITY 20 0.10 25 TIVE HUM 10% RELA 10 10 0.05 0 30 20 0 30 40 50 60 STANDARD AIR 70 80 90 100 110 115 DRY BULB TEMPERATURE - °F Chart by: HANDS DOWN SOFTWARE, www.handsdownsoftware.com
10 15 20 25 ENTHALPY - Btu per lb. of dry air and associated moisture Adiabatic Saturation 55 0.20 0.25 0.30 • Evaporative Cooling SENSIBLE HEAT RATIO = Qs / Qt
0.35 90 • Evaporative Humidification 5 0 200 1.30
1 4 1.25 . 190 • Constant enthalpy process 6 1 1 85 4 5 . . 85 8 0 1.20 180 0.40
e r 45 1.15 tu is o 170 m BAROMETRIC PRESSURE: 29.921 in. HG d 1.10 te 1 a 4 i . c 4 55 o s s F 160 1.05 a ° 0.45 d - 80 n E 80 a r R i U a T 1.00 y r A 150 d 40 R f E o P R . I M lb A E 0.95 r 1 0.50
T Y e 4 WE p B . T R L 2 B 140 u U D t U LB B B T F - E 0.90
T M O P Y E E
P 75 R D W AT 75 5 L U N 0 A R 130 0.55 U E e H - r ° O 0.85
T F u t N P
s E i
3 R 5 o Y E m R
P 0.80 1 4 120 d 0.60 U E e C
. t 0 R F a R i ° U c E - T
o M
S E s 0.75
70 I s F 70 R O a 0.65
% 110 O U
0 M d T 9 S n F A E a
R 3 O 0.70 r
0 H
i E a S C
0.70 Evaporatively Cooled Supply Air P 1 N y N I I
4 r
3 M 100 5 - d . A E
8
f 0.65
% R T E
0 o
8 G 0.75 . R T
) 65 b U N l
y 65 I t r S i O e S d i
90 P 0.60 p 0.80 E
m u 2 R t u 5 W P B E H
%
0 - 0.85 D R
1 7 c i
3 f Y O . i 0.55 c 6 P 80 0.90 P e L
60 A p A
Hot & Dry OA 60 V S H
r 0.95
T 0.50 o ( N 0% 6 E 1.00 O 2 70 I t 0 T 4 1 0 A
3 Q 0.45
55 . R / 4 55 Y s T I % Q
0 60 D 0.40 5 I =
M U O 50 1 I H
3 50 T 1 . 0.35 5 2 50 A R 0% 45 4 T 45 A 0.30
1 E 3 . H 0 40 40 E 0% 40 35 L 0.25 3 B 1 I
2 S 35 . 8 30 35 N 0.20 32 E S 1 10 30 2 . 0% 30 6 2 0.15 20 25 IDITY 20 0.10 25 TIVE HUM 10% RELA 10 10 0.05 0 30 20 0 30 40 50 60 STANDARD AIR 70 80 90 100 110 115 DRY BULB TEMPERATURE - °F Chart by: HANDS DOWN SOFTWARE, www.handsdownsoftware.com
10 15 20 25 ENTHALPY - Btu per lb. of dry air and associated moisture Humidification – Steam Injection 55 0.20 0.25 0.30 • Adds both sensible and latent SENSIBLE HEAT RATIO = Qs / Qt
0.35 90 heat to the airstream. 5 0 200 1.30
1 4 1.25 . 190 • Exact slope varies by selection. 6 1 1 85 4 5 . . 85 8 0 1.20 180 0.40
e r 45 1.15 tu is o 170 m BAROMETRIC PRESSURE: 29.921 in. HG d 1.10 te 1 a 4 i . c 4 55 o s s F 160 1.05 a ° 0.45 d - 80 n E 80 a r R i U a T 1.00 y r A 150 d 40 R f E o P R . I M lb A E 0.95 r 1 0.50
T Y e 4 WE p B . T R L 2 B 140 u U D t U LB B B T F - E 0.90
T M O P Y E E
P 75 R D W AT 75 5 L U N 0 A R 130 0.55 U E e H - r ° O 0.85
T F u t N P
s E i
3 R 5 o Y E m R
P 0.80 1 4 120 d 0.60 U E e C
. t 0 R F a R i ° U c E - T
o M
S E s 0.75
70 I s F 70 R O a 0.65
% 110 O U
0 M d T 9 S n F A E a
R 3 O 0.70 r
0 H
i E a S C
0.70 1 P N y N I I
4 r
3 M 100 5 - d . A E
8
f 0.65
% R T E
0 o
8 G 0.75 . R T
) 65 b U N l
y 65 I t r S i O e S d i
90 P 0.60 p 0.80 E
m u 2 R t u 5 W P B E H
%
0 - 0.85 D R
1 7 c i
3 f Y O . i 0.55 c 6 P 80 0.90 P e L
60 A
Winter: Humidified Air p A
60 V S H
r 0.95
T 0.50 o ( N 0% 6 E 1.00 O 2 70 I t 0 T 4 1 0 A
3 Q 0.45
55 . R / 4 55 Y s T I % Q
0 60 D 0.40 5 I =
M U O 50 1 I H
3 50 T 1 . 0.35 5 2 50 A R 0% 45 4 T 45 A 0.30
1 E 3 . H 0 40 40 E 0% 40 35 L 0.25 3 B 1 I
2 S 35 . 8 30 35 N 0.20 32 E S 1 10 30 2 . 0% 30 6 2 0.15 20 25 IDITY 20 0.10 25 Winter: Dry Air TIVE HUM 10% RELA 10 10 0.05 0 30 20 0 30 40 50 60 STANDARD AIR 70 80 90 100 110 115 DRY BULB TEMPERATURE - °F Chart by: HANDS DOWN SOFTWARE, www.handsdownsoftware.com
10 15 20 25 ENTHALPY - Btu per lb. of dry air and associated moisture Energy Recovery: Sensible 55 0.20 0.25 0.30 • OA: 95/78 to 83/75 SENSIBLE HEAT RATIO = Qs / Qt
0.35 90 • EA: 75/63 to 89/67 5 0 200 1.30
1 4 1.25 . 190 • Dt = 12°F 6 OA 1 1 85 4 5 . . 85 8 0 1.20 • DhOA = 3.3 BTU/lbm 180 0.40 e r 45 1.15 tu is o 170 m BAROMETRIC PRESSURE: 29.921 in. HG d 1.10 te 1 a 4 i . c 4 55 o s s F 160 1.05 a ° 0.45 d - 80 n E 80 a r R i U a T 1.00 y r A 150 d 40 R f E o P R . I M lb A E 0.95 r 1 0.50
T Y e 4 WE p B . T R L 2 B 140 u U D t U LB B B T F - E 0.90
T M O P Y E E
P 75 R D W AT 75 5 L U N 0 A R 130 0.55 U E e H - r ° O 0.85
T F u t N P
s E i
3 R 5 o Y E m Summer: Leaving OA R Summer: Entering OA P 0.80 1 4 120 d 0.60 U E e C
. t 0 R F a R i ° U c E - T
o M
S E s 0.75
70 I s F 70 R O a 0.65
% 110 O U
0 M d T 9 S n F A E a
R 3 O 0.70 r
0 H
i E a S C
0.70 1 P N y N I I
4 r
3 M 100 5 - d . A E
8
f 0.65
% R T E
0 o
8 G 0.75 . R T
) 65 b U N l
y 65 I t r S i O e S d i
90 P 0.60 p 0.80 E
m u 2 R t u 5 W P B E H
%
0 - 0.85 D R
1 7 c i
3 f Y O . i 0.55 c 6 P 80 0.90 P e L
60 A p A
60 V S H
r 0.95
T 0.50 o ( N 0% 6 E 1.00 O 2 70 I t 0 Summer: Entering EA Summer: Leaving EA T 40 1 A
3 Q 0.45
55 . R / 4 55 Y s T I % Q
0 60 D 0.40 5 I =
M U O 50 1 I H
3 50 T 1 . 0.35 5 2 50 A R 0% 45 4 T 45 A 0.30
1 E 3 . H 0 40 40 E 0% 40 35 L 0.25 3 B 1 I
2 S 35 . 8 30 35 N 0.20 32 E S 1 10 30 2 . 0% 30 6 2 0.15 20 25 IDITY 20 0.10 25 TIVE HUM 10% RELA 10 10 0.05 0 30 20 0 30 40 50 60 STANDARD AIR 70 80 90 100 110 115 DRY BULB TEMPERATURE - °F Chart by: HANDS DOWN SOFTWARE, www.handsdownsoftware.com
10 15 20 25 ENTHALPY - Btu per lb. of dry air and associated moisture Energy Recovery: Sensible 55 0.20 0.25 0.30 • OA: 10/9 to 49/34 SENSIBLE HEAT RATIO = Qs / Qt
0.35 90 • EA: 70/53 to 33/32 5 0 200 1.30
1 4 1.25 . 190 • Dt = 39°F 6 OA 1 1 85 4 5 . . 85 8 0 1.20 • DhOA = 9.1 BTU/lbm 180 0.40 e r 45 1.15 tu is o 170 m BAROMETRIC PRESSURE: 29.921 in. HG d 1.10 te 1 a 4 i . c 4 55 o s s F 160 1.05 a ° 0.45 d - 80 n E 80 a r R i U a T 1.00 y r A 150 d 40 R f E o P R . I M lb A E 0.95 r 1 0.50
T Y e 4 WE p B . T R L 2 B 140 u U D t U LB B B T F - E 0.90
T M O P Y E E
P 75 R D W AT 75 5 L U N 0 A R 130 0.55 U E e H - r ° O 0.85
T F u t N P
s E i
3 R 5 o Y E m R
P 0.80 1 4 120 d 0.60 U E e C
. t 0 R F a R i ° U c E - T
o M
S E s 0.75
70 I s F 70 R O a 0.65
% 110 O U
0 M d T 9 S n F A E a
R 3 O 0.70 r
0 H
i E a S C
0.70 1 P N y N I I
4 r
3 M 100 5 - d . A E
8
f 0.65
% R T E
0 o
8 G 0.75 . R T
) 65 b U N l
y 65 I t r S i O e S d i
90 P 0.60 p 0.80 E
m u 2 R t u 5 W P B E H
%
0 - 0.85 D R
1 7 c i
3 f Y O . i 0.55 c 6 P 80 0.90 P e L
60 A p A
60 V S H
r 0.95
T 0.50 o ( N 0% 6 E 1.00 O 2 70 I t 0 T 4 1 0 A
3 Q 0.45
55 . R / 4 55 Y s T I % Q
0 60 D 0.40 5 I =
M U O 50 1 I H
3 50 T 1 . 0.35 5 2 50 A R 0% 45 4 T 45 A 0.30
1 E 3 . H 0 40 40 E Winter:0% Entering EA 40 35 L 0.25 3 B 1 I
2 S 35 . 8 30 35 N 0.20 32 Winter: Leaving EA E S 1 10 30 2 . 0% 30 6 2 0.15 20 25 IDITY 20 0.10 25 TIVE HUM 10% RELA Winter: Leaving OA 10 Entering OA Winter: 10 0.05 0 30 20 0 30 40 50 60 STANDARD AIR 70 80 90 100 110 115 DRY BULB TEMPERATURE - °F Chart by: HANDS DOWN SOFTWARE, www.handsdownsoftware.com
10 15 20 25 ENTHALPY - Btu per lb. of dry air and associated moisture Heat Recovery Performance Energy Recovery: Total 55 0.20 0.25 0.30 • OA: 95/78 to 83/71 SENSIBLE HEAT RATIO = Qs / Qt
0.35 90 • EA: 75/64 to 89/74 5 0 200 1.30
1 4 1.25 . 190 • Dt = 12°F 6 OA 1 1 85 4 5 . . 85 8 0 1.20 • DhOA = 6.7 BTU/lbm 180 0.40 e r 45 1.15 tu is o 170 m BAROMETRIC PRESSURE: 29.921 in. HG d 1.10 te 1 a 4 i . c 4 55 o s s F 160 1.05 a ° 0.45 d - 80 n E 80 a r R i U a T 1.00 y r A 150 d 40 R f E o P R . I M lb A E 0.95 r 1 0.50
T Y e 4 WE p B . T R L 2 B 140 u U D t U LB B B T F - E 0.90
T M O P Y E E
P 75 R D W AT 75 5 L U N 0 A R 130 0.55 U E e H - r ° O 0.85
T F u t N P
s E i
3 R 5 o Y E m R
Summer OA: Entering P 0.80 1 4 120 d 0.60 U E e C
. t 0 R F a R i ° U c E - T
o M
S E s 0.75
70 I s F 70 R O a 0.65
% 110 O U
0 M d T 9 S n F A E Summer EA: Leaving a
R 3 O 0.70 r
0 H
i E a S C
0.70 1 P N y N I I
4 r
3 M 100 5 - d . A E
8
Summer OA: Leaving f 0.65
% R T E
0 o
8 G 0.75 . R T
) 65 b U N l
y 65 I t r S i O e S d i
90 P 0.60 p 0.80 E
m u 2 R t u 5 W P B E H
%
0 - 0.85 D R
1 7 c i
3 f Y O . i 0.55 c 6 P 80 0.90 P e L
60 A p A
60 V S H
Summer EA: Entering r 0.95 T 0.50 o ( N 0% 6 E 1.00 O 2 70 I t 0 T 4 1 0 A
3 Q 0.45
55 . R / 4 55 Y s T I % Q
0 60 D 0.40 5 I =
M U O 50 1 I H
3 50 T 1 . 0.35 5 2 50 A R 0% 45 4 T 45 A 0.30
1 E 3 . H 0 40 40 E 0% 40 35 L 0.25 3 B 1 I
2 S 35 . 8 30 35 N 0.20 32 E S 1 10 30 2 . 0% 30 6 2 0.15 20 25 IDITY 20 0.10 25 TIVE HUM 10% RELA 10 10 0.05 0 30 20 0 30 40 50 60 STANDARD AIR 70 80 90 100 110 115 DRY BULB TEMPERATURE - °F Chart by: HANDS DOWN SOFTWARE, www.handsdownsoftware.com
10 15 20 25 ENTHALPY - Btu per lb. of dry air and associated moisture Energy Recovery: Total 55 0.20 0.25 0.30 • OA: 0/0 to 46/45.2 SENSIBLE HEAT RATIO = Qs / Qt
0.35 90 • EA: 75/64 to 28.2/28.2 5 0 200 1.30
1 4 1.25 . 190 • Dt = 46°F 6 OA 1 1 85 4 5 . . 85 8 0 1.20 • DhOA = 16.9 BTU/lbm 180 0.40 e r 45 1.15 tu is o 170 m BAROMETRIC PRESSURE: 29.921 in. HG d 1.10 te 1 a 4 i . c 4 55 o s s F 160 1.05 a ° 0.45 d - 80 n E 80 a r R i U a T 1.00 y r A 150 d 40 R f E o P R . I M lb A E 0.95 r 1 0.50
T Y e 4 WE p B . T R L 2 B 140 u U D t U LB B B T F - E 0.90
T M O P Y E E
P 75 R D W AT 75 5 L U N 0 A R 130 0.55 U E e H - r ° O 0.85
T F u t N P
s E i
3 R 5 o Y E m R
P 0.80 1 4 120 d 0.60 U E e C
. t 0 R F a R i ° U c E - T
o M
S E s 0.75
70 I s F 70 R O a 0.65
% 110 O U
0 M d T 9 S n F A E a
R 3 O 0.70 r
0 H
i E a S C
0.70 1 P N y N I I
4 r
3 M 100 5 - d . A E
8
f 0.65
% R T E
0 o
8 G 0.75 . R T
) 65 b U N l
y 65 I t r S i O e S d i
90 P 0.60 p 0.80 E
m u 2 R t u 5 W P B E H
%
0 - 0.85 D R
1 7 c i
3 f Y O . i 0.55 c 6 P 80 0.90 P e L
60 A p A
60 V S H
Winter EA: Entering r 0.95 T 0.50 o ( N 0% 6 E 1.00 O 2 70 I t 0 T 4 1 0 A
3 Q 0.45
55 . R / 4 55 Y s T I % Q
0 60 D 0.40 5 I =
M U O 50 1 I H
3 50 T 1 . 0.35 5 2 50 A R 0% 45 Winter OA: Leaving 4 T 45 A 0.30
1 E 3 . H 0 40 40 E 0% 40 35 L 0.25 3 B 1 I
2 S 35 . 8 30 35 N 0.20 32 E S Winter EA: Leaving1 10 30 2 . 0% 30 6 2 0.15 20 25 IDITY 20 0.10 25 TIVE HUM 10% RELA 10 10 0.05 0 30 20 0 30 40 50 60 STANDARD AIR 70 80 90 100 110 115 DRY BULB TEMPERATURE - °F Chart by: HANDS DOWN SOFTWARE, www.handsdownsoftware.com
10 15 20 25 ENTHALPY - Btu per lb. of dry air and associated moisture Enthalpy Wheel Performance HVAC PSYCHROMETRICS Psychrometrics of Systems HVAC Psychrometrics DRAWING A SYSTEM Drawing a System 55 0.20 0.25 0.30 • Identify the Outdoor Air Condition SENSIBLE HEAT RATIO = Qs / Qt
0.35 90 • Identify the Return Air Condition 5 0 200 1.30
1 4 1.25 . 190 6 1 1 85 4 5 . . 85 8 0 1.20 180 0.40
e r 45 1.15 tu is o 170 m BAROMETRIC PRESSURE: 29.921 in. HG d 1.10 te 1 a 4 i . c 4 55 o s s F 160 1.05 a 0.45 ° d - 80 n E 80 a r R i U a T 1.00 y r A 150 d 40 R f E
o P R . I M b A l E 0.95 r 1 0.50 T Y e 4 WE p B . T R L 2 B 140 u U D t U LB B B T F - E 0.90 T M O P Y E E
75 R D P W AT 75 5 L U N 0 A R 0.55
130 U
E e H - r ° O 0.85 T F u t P
N s E i
3 R 5 o Y E m R
Outdoor Air P 0.80 1 4 120 d 0.60 U E e C
. t 0 R F a R i ° U
c E - T
o M S s
E 0.75 70 I s F R
O 70 a 0.65 110 % O U
0 M d T 9 S n F A a E
R 3 O 0.70 r
0 H i E a S 0.70 C
P y
1 N N
I 4 r I 3 M 100 5 d - . A E
8
f 0.65 R
% T E
0 o
8 G 0.75 . R T
)
65 b U N l y 65 I t r S i O e d S 90 i 0.60 P 0.80 p E
m u 2 R u t 5 W P B E H
% 0.85 0 - D R
1 c
7 i
3 f . i Y 0.55 O
6 c 80 P 0.90 P e L 60 A p A 60 V S
H
r 0.95
T 0.50 o ( N 0% 1.00 E
6 O 70 I t 20 Return Air T 40 1 A 3 Q 0.45
R 55 . /
4 55 Y s T I Q
% 0 60 D 0.40 I
5 =
M O U I 50 1 H 3 50 T
. A 15 2 0.35
50 R % 40 T
45 A 45 0.30 1 E 3 H
. 0 40 E
40 L % 40 35 0.25 0 B
3 I 1 2 S . 35 N 8 30 35 0.20 E
32 S 30 1 10 2 . 0% 30 6 2 0.15 20 25 IDITY 20 0.10 25 TIVE HUM 10% RELA 10 10 0.05 0 30 20 0 30 40 50 60 STANDARD AIR 70 80 90 100 110 115 DRY BULB TEMPERATURE - °F Chart by: HANDS DOWN SOFTWARE, www.handsdownsoftware.com
10 15 20 25 ENTHALPY - Btu per lb. of dry air and associated moisture Drawing a System 55 0.20 0.25 0.30 • Draw the mixing line between both SENSIBLE HEAT RATIO = Qs / Qt
0.35 90 state points. 5 0 200 1.30
1 4 1.25 • . 190 Locate the mixed air condition based 6 1 1 85 4 5 . . 85 8 0 1.20 on OA percentage. 180 0.40 e r 45 1.15 tu is o 170 m BAROMETRIC PRESSURE: 29.921 in. HG d 1.10 te 1 a 4 i . c 4 55 o s s F 160 1.05 a 0.45 ° d - 80 n E 80 a r R i U a T 1.00 y r A 150 d 40 R f E
o P R . I M b A l E 0.95 r 1 0.50 T Y e 4 WE p B . T R L 2 B 140 u U D t U LB B B T F - E 0.90 T M O P Y E E
75 R D P W AT 75 5 L U N 0 A R 0.55
130 U
E e H - r ° O 0.85 T F u t P
N s E i
3 R 5 o Y E m R
Outdoor Air P 0.80 1 4 120 d 0.60 U E e C
. t 0 R F a R i ° U
c E - T
o M S s
E 0.75 70 I s F R
O 70 a 0.65 110 % O U
0 M d T 9 S n F A a E
R 3 O 0.70 r
0 H i E a S 0.70 C
P y
1 N N
I 4 r I 3 M 100 5 d - . A E
8
f 0.65 R
% T E
0 o
8 G 0.75 . R T
)
65 b U N l y 65 I t r S i O e d S 90 i 0.60 P 0.80 p E
m u 2 R u t 5 W P B E H
% 0.85 0 - D R
1 c
7 i
3 f . i Y 0.55 O
6 c 80 P 0.90 P e L 60 Mixed Air: 20% OA A p A 60 V S
H
r 0.95
T 0.50 o ( N 0% 1.00 E
6 O 70 I t 20 Return Air T 40 1 A 3 Q 0.45
R 55 . /
4 55 Y s T I Q
% 0 60 D 0.40 I
5 =
M O U I 50 1 H 3 50 T
. A 15 2 0.35
50 R % 40 T
45 A 45 0.30 1 E 3 H
. 0 40 E
40 L % 40 35 0.25 0 B
3 I 1 2 S . 35 N 8 30 35 0.20 E
32 S 30 1 10 2 . 0% 30 6 2 0.15 20 25 IDITY 20 0.10 25 TIVE HUM 10% RELA 10 10 0.05 0 30 20 0 30 40 50 60 STANDARD AIR 70 80 90 100 110 115 DRY BULB TEMPERATURE - °F Chart by: HANDS DOWN SOFTWARE, www.handsdownsoftware.com
10 15 20 25 ENTHALPY - Btu per lb. of dry air and associated moisture Drawing a System 55 0.20 0.25 0.30 • Draw the cooling coil curve SENSIBLE HEAT RATIO = Qs / Qt
0.35 90 down to the leaving cooling 5 0 200 1.30
1 4 1.25 . 190 coil condition. 6 1 1 85 4 5 . . 85 8 0 1.20 • Does not quite reach 180 0.40 e r 45 1.15 tu is o 170 m saturation;BAROMETRIC PRESSURE: 29.921 most in. HG d 1.10 te 1 a 4 i . c 4 55 o s s F 160 1.05 a 0.45 ° d - 80 psychrometric charts have n 80 E a r R i U a T 1.00 y r A 150 d 40 R f E
o P R cooling coil lines. . I M b A l E 0.95 r 1 0.50 T Y e 4 WE p B . T R L 2 B 140 u U D t U LB B B T F - E 0.90 T M O P Y E E
75 R D P W AT 75 5 L U N 0 A R 0.55
130 U
E e H - r ° O 0.85 T F u t P
N s E i
3 R 5 o Y E m R
Outdoor Air P 0.80 1 4 120 d 0.60 U E e C
. t 0 R F a R i ° U
c E - T
o M S s
E 0.75 70 I s F R
O 70 a 0.65 110 % O U
0 M d T 9 S n F A a E
R 3 O 0.70 r
0 H i E a S 0.70 C
P y
1 N N
I 4 r I 3 M 100 5 d - . A E
8
f 0.65 R
% T E
0 o
8 G 0.75 . R T
)
65 b U N l y 65 I t r S i O e d S 90 i 0.60 P 0.80 p E
m u 2 R u t 5 W P B E H
% 0.85 0 - D R
1 c
7 i
3 f . i Y 0.55 O
6 c 80 P 0.90 P e L 60 Mixed Air: 20% OA A p A 60 V S
H
r 0.95
T 0.50 o ( N 0% 1.00 E
6 O 70 I t 20 Return Air T 40 1 A 3 Q 0.45
R 55 . /
4 55 Y s T I
Leaving Cooling Coil Q
% 0 60 D 0.40 I
5 =
M O U I 50 1 H 3 50 T
. A 15 2 0.35
50 R % 40 T
45 A 45 0.30 1 E 3 H
. 0 40 E
40 L % 40 35 0.25 0 B
3 I 1 2 S . 35 N 8 30 35 0.20 E
32 S 30 1 10 2 . 0% 30 6 2 0.15 20 25 IDITY 20 0.10 25 TIVE HUM 10% RELA 10 10 0.05 0 30 20 0 30 40 50 60 STANDARD AIR 70 80 90 100 110 115 DRY BULB TEMPERATURE - °F Chart by: HANDS DOWN SOFTWARE, www.handsdownsoftware.com
10 15 20 25 ENTHALPY - Btu per lb. of dry air and associated moisture Drawing a System 55 0.20 0.25 0.30 • The leaving cooling coil SENSIBLE HEAT RATIO = Qs / Qt
0.35 90 condition, in the draw through 5 0 200 1.30
1 4 1.25 . 190 system, is not the supply air 6 1 1 85 4 5 . . 85 8 0 1.20 temperature. 180 0.40 e r 45 1.15 tu is o 170 • m FanBAROMETRIC heat PRESSURE: is 29.921 a in. sensible HG only d 1.10 te 1 a 4 i . c 4 55 o s s F 160 1.05 a 0.45 ° d - 80 heating process. n 80 E a r R i U a T 1.00 y r A 150 d 40 R f E
o P R . I M b A l E 0.95 r 1 0.50 T Y e 4 WE p B . T R L 2 B 140 u U D t U LB B B T F - E 0.90 T M O P Y E E
75 R D P W AT 75 5 L U N 0 A R 0.55
130 U
E e H - r ° O 0.85 T F u t P
N s E i
3 R 5 o Y E m R
Outdoor Air P 0.80 1 4 120 d 0.60 U E e C
. t 0 R F a R i ° U
c E - T
o M S s
E 0.75 70 I s F R
O 70 a 0.65 110 % O U
0 M d T 9 S n F A a E
R 3 O 0.70 r
0 H i E a S 0.70 C
P y
1 N N
I 4 r I 3 M 100 5 d - . A E
8
f 0.65 R
% T E
0 o
8 G 0.75 . R T
)
65 b U N l y 65 I t r S i O e d S 90 i 0.60 P 0.80 p E
m u 2 R u t 5 W P B E H
% 0.85 0 - D R
1 c
7 i
3 f . i Y 0.55 O
6 c 80 P 0.90 P e L 60 Mixed Air: 20% OA A p A 60 V S
H
r 0.95
T 0.50 o ( N 0% 1.00 E
6 O 70 I t 20 Return Air T 40 1 A 3 Q 0.45
R 55 . /
4 55 Y s T I
- Supply Air Temperature Q
% 0 60 D 0.40 I
5 =
M O U I 50 1 H 3 50 T
. A 15 2 0.35
50 R % 40 T
45 A 45 0.30 1 E 3 H
. 0 40 E
40 L % 40 35 0.25 0 B
3 I 1 2 S . 35 N 8 30 35 0.20 E
32 S 30 1 10 2 . 0% 30 6 2 0.15 20 25 IDITY 20 0.10 25 TIVE HUM 10% RELA 10 10 0.05 0 30 20 0 30 40 50 60 STANDARD AIR 70 80 90 100 110 115 DRY BULB TEMPERATURE - °F Chart by: HANDS DOWN SOFTWARE, www.handsdownsoftware.com
10 15 20 25 ENTHALPY - Btu per lb. of dry air and associated moisture Drawing a System 55 0.20 0.25 0.30 • Close the system. SENSIBLE HEAT RATIO = Qs / Qt
0.35 90 • Be careful and follow the 5 0 200 1.30
1 4 1.25 . 190 sensible heat ratio slope from 6 1 1 85 4 5 . . 85 8 0 1.20 your load calculations. 180 0.40 e r 45 1.15 tu is o 170 • m DOBAROMETRIC NOT PRESSURE: just 29.921 in. close HG the system d 1.10 te 1 a 4 i . c 4 55 o s s F 160 1.05 a 0.45 ° d - 80 loop. n 80 E a r R i U a T 1.00 y r A 150 d 40 R f E
o P R . I M b A l E 0.95 r 1 0.50 T Y e 4 WE p B . T R L 2 B 140 u U D t U LB B B T F - E 0.90 T M O P Y E E
75 R D P W AT 75 5 L U N 0 A R 0.55
130 U
E e H - r ° O 0.85 T F u t P
N s E i
3 R 5 o Y E m R
Outdoor Air P 0.80 1 4 120 d 0.60 U E e C
. t 0 R F a R i ° U
c E - T
o M S s
E 0.75 70 I s F R
O 70 a 0.65 110 % O U
0 M d T 9 S n F A a E
R 3 O 0.70 r
0 H i E a S 0.70 C
P y
1 N N
I 4 r I 3 M 100 5 d - . A E
8
f 0.65 R
% T E
0 o
8 G 0.75 . R T
)
65 b U N l y 65 I t r S i O e d S 90 i 0.60 P 0.80 p E
m u 2 R u t 5 W P B E H
% 0.85 0 - D R
1 c
7 i
3 f . i Y 0.55 O
6 c 80 P 0.90 P e L 60 Mixed Air: 20% OA A p A 60 V S
H
r 0.95
Space Condition T 0.50 o ( N 0% 1.00 E
6 O 70 I t 20 Return Air T 40 1 A 3 Q 0.45
R 55 . /
4 55 Y s T I
- Supply Air Temperature Q
% 0 60 D 0.40 I
5 =
M O U I 50 1 H 3 50 T
. A 15 2 0.35
50 R % 40 T
45 A 45 0.30 1 E 3 H
. 0 40 E
40 L % 40 35 0.25 0 B
3 I 1 2 S . 35 N 8 30 35 0.20 E
32 S 30 1 10 2 . 0% 30 6 2 0.15 20 25 IDITY 20 0.10 25 TIVE HUM 10% RELA 10 10 0.05 0 30 20 0 30 40 50 60 STANDARD AIR 70 80 90 100 110 115 DRY BULB TEMPERATURE - °F Chart by: HANDS DOWN SOFTWARE, www.handsdownsoftware.com
10 15 20 25 ENTHALPY - Btu per lb. of dry air and associated moisture Drawing a System 55 0.20 0.25 0.30 • Iterate to determine system SENSIBLE HEAT RATIO = Qs / Qt
0.35 90 conditions. 5 0 200 1.30
1 4 1.25 • . 190 Sometimes you will find that 6 1 1 85 4 5 . . 85 8 0 1.20 the space conditions are 180 0.40 e r 45 1.15 tu is o 170 m outsideBAROMETRIC PRESSURE: acceptable 29.921 in. HG design d 1.10 te 1 a 4 i . c 4 55 o s s F 160 1.05 a 0.45 ° d - 80 conditions. n 80 E a r R i U a T 1.00 y r A 150 d 40 R f E
o P R . I M b A l E 0.95 r 1 0.50 T Y e 4 WE p B . T R L 2 B 140 u U D t U LB B B T F - E 0.90 T M O P Y E E
75 R D P W AT 75 5 L U N 0 A R 0.55
130 U
E e H - r ° O 0.85 T F u t P
N s E i
3 R 5 o Y E m R
Outdoor Air P 0.80 1 4 120 d 0.60 U E e C
. t 0 R F a R i ° U
c E - T
o M S s
E 0.75 70 I s F R
O 70 a 0.65 110 % O U
0 M d T 9 S n F A a E
R 3 O 0.70 r
0 H i E a S 0.70 C
P y
1 N N
I 4 r I 3 M 100 5 d - . A E
8
f 0.65 R
% T E
0 o
8 G 0.75 . R T
)
65 b U N l y 65 I t r S i O e d S 90 i 0.60 P 0.80 p E
m u 2 R u t 5 W P B E H
% Mixed Air: 20% OA 0.85 0 - D R
1 c
7 i
3 f . i Y 0.55 O
6 c 80 P 0.90 P e L 60 A p A 60 V S
H
r 0.95
ReturnSpace Condition Air T 0.50 o ( N 0% 1.00 E
6 O 70 I t 20 T 4 1 0 A 3 Q 0.45
R 55 . /
4 55 Y s T I
- Supply Air Temperature Q
% 0 60 D 0.40 I
5 =
M O U I 50 1 H 3 50 T
. A 15 2 0.35
50 R % 40 T
45 A 45 0.30 1 E 3 H
. 0 40 E
40 L % 40 35 0.25 0 B
3 I 1 2 S . 35 N 8 30 35 0.20 E
32 S 30 1 10 2 . 0% 30 6 2 0.15 20 25 IDITY 20 0.10 25 TIVE HUM 10% RELA 10 10 0.05 0 30 20 0 30 40 50 60 STANDARD AIR 70 80 90 100 110 115 DRY BULB TEMPERATURE - °F Chart by: HANDS DOWN SOFTWARE, www.handsdownsoftware.com
10 15 20 25 ENTHALPY - Btu per lb. of dry air and associated moisture HVAC Psychrometrics AIR SIDE SYSTEM ANALYSIS AIR SIDE SYSTEM ANALYSIS
Common Equations
QSensible = 1.08 x CFM x Dt [BTU/hr]
QLatent = 0.68 x CFM x Dw Change [BTU/hr]
QTotal = 4.45 x CFM x Dh [BTU/hr]
QTotal = Qsensible + QLatent Constant Air Volume (CAV): 55 0.20 0.25 0.30 Design Day - Auditorium SENSIBLE HEAT RATIO = Qs / Qt
0.35 • 90 High (60%) space RH at design 5 0 200 1.30
1 4 1.25 . 190 day. 6 1 1 85 4 5 . . 85 8 0 1.20 • Design loads are with lights on. 180 0.40 e r 45 1.15 tu is o 170 m BAROMETRIC PRESSURE: 29.921 in. HG d 1.10 te 1 a 4 i . c 4 55 o s s F 160 1.05 a 0.45 ° d - 80 n E 80 a r R i U a T 1.00 y r A 150 d 40 R f E
o P R . I M b A l E 0.95 r 1 0.50 T Y e 4 WE p B . T R L 2 B 140 u U D t U LB B B T F - E 0.90 T M O P Y E E
75 R D P W AT 75 5 L U N 0 A R 0.55
130 U
E e H - r ° O 0.85 T F u t P
N s E i
3 R 5 o Y E m R
Outdoor Air P 0.80 1 4 120 d 0.60 U E e C
. t 0 R F a R i ° U
c E - T
o M S s
E 0.75 70 I s F R
O 70 a 0.65 110 % O U
0 M d T 9 S n F A a E
R 3 O 0.70 r
0 H i E a S 0.70 C
P y
1 N N
I 4 r I 3 M 100 5 d - . A E
8
f 0.65 R
% T E
0 o
8 G 0.75 . R T
)
65 b U N l y 65 I t r S i O e
Mixed Air: 25% OA d S 90 i 0.60 P 0.80 p E
m u 2 R u t 5 W P B E H
% 0.85 0 - D R
1 c
7 i
3 f . ReturnSpace Condition Air i Y 0.55 O
6 c 80 P 0.90 P e L 60 A p A 60 V S
H
r 0.95
T 0.50 o ( N 0% 1.00 E
6 O 70 I t 20 T 4 1 0 A 3 Q 0.45
R 55 . /
4 55 Y s T I
- Supply Air Temperature Q
% 0 60 D 0.40 I
5 =
M O U I 50 1 H 3 50 T
. A 15 2 0.35
50 R % 40 T
45 A 45 0.30 1 E 3 H
. 0 40 E
40 L % 40 35 0.25 0 B
3 I 1 2 S . 35 N 8 30 35 0.20 E
32 S 30 1 10 2 . 0% 30 6 2 0.15 20 25 IDITY 20 0.10 25 TIVE HUM 10% RELA 10 10 0.05 0 30 20 0 30 40 50 60 STANDARD AIR 70 80 90 100 110 115 DRY BULB TEMPERATURE - °F Chart by: HANDS DOWN SOFTWARE, www.handsdownsoftware.com
10 15 20 25 ENTHALPY - Btu per lb. of dry air and associated moisture CAV - Off Design: No Reheat 55 0.20 0.25 0.30 • Lights turned off. SENSIBLE HEAT RATIO = Qs / Qt
0.35 90 • CAV adjusts SAT for temperature 5 0 200 1.30
1 4 1.25 . 190 control. 6 1 1 85 4 5 . . 85 8 0 1.20 • Results in 73% RH in the space. 180 0.40 e r 45 1.15 tu is o 170 m BAROMETRIC PRESSURE: 29.921 in. HG d 1.10 te 1 a 4 i . c 4 55 o s s F 160 1.05 a 0.45 ° d - 80 n E 80 a r R i U a T 1.00 y r A 150 d 40 R f E
o P R . I M b A l E 0.95 r 1 0.50 T Y e 4 WE p B . T R L 2 B 140 u U D t U LB B B T F - E 0.90 T M O P Y E E
75 R D P W AT 75 5 L U N 0 A R 0.55
130 U
E e H - r ° O 0.85 T F u t P
N s E i
3 R 5 o Y E m R
P 0.80 1 4 120 d 0.60 U E e C
. t 0 R F a R i ° U
c E - T
o M S s
E 0.75 70 I s F R
O 70 a 0.65 110 % O U
0 M d T 9 S n F A a E
R 3 O 0.70 r
0 H i E a S 0.70 C
P y
1 N N
I 4 r I 3 50% Load Space Condition M 100 5 d - . A E
8
f 0.65 R
% T E
0 o
8 G 0.75 . R T
)
65 b U N l y 65 I t r S i O e d S 90 i 0.60 P 0.80 p E
m u 2 R u t 5 W P B E H
% 0.85 0 - D R
1 c
7 i
3 f . ReturnSpace Condition Air i Y 0.55 O
6 c - 50% Load SAT 80 P 0.90 P e L 60 A p A 60 V S
H
r 0.95
T 0.50 o ( N 0% 1.00 E
6 O 70 I t 20 T 4 1 0 A 3 Q 0.45
R 55 . /
4 55 Y s T I
- Supply Air Temperature Q
% 0 60 D 0.40 I
5 =
M O U I 50 1 H 3 50 T
. A 15 2 0.35
50 R % 40 T
45 A 45 0.30 1 E 3 H
. 0 40 E
40 L % 40 35 0.25 0 B
3 I 1 2 S . 35 N 8 30 35 0.20 E
32 S 30 1 10 2 . 0% 30 6 2 0.15 20 25 IDITY 20 0.10 25 TIVE HUM 10% RELA 10 10 0.05 0 30 20 0 30 40 50 60 STANDARD AIR 70 80 90 100 110 115 DRY BULB TEMPERATURE - °F Chart by: HANDS DOWN SOFTWARE, www.handsdownsoftware.com
10 15 20 25 ENTHALPY - Btu per lb. of dry air and associated moisture CAV - Off Design: With Reheat 55 0.20 0.25 0.30 • Lights turned off. SENSIBLE HEAT RATIO = Qs / Qt
0.35 90 • CAV adjusts SAT for temperature 5 0 200 1.30
1 4 1.25 . 190 control. 6 1 1 85 4 5 . . 85 8 0 1.20 • Reheat coil kicks in for humidity 180 0.40 e r 45 1.15 tu is o 170 m control.BAROMETRIC PRESSURE: 29.921 in. HG d 1.10 te 1 a 4 i . c 4 55 o s s F 160 1.05 a 0.45 ° d - 80 n E 80 a r R i U a T 1.00 y r A 150 d 40 R f E
o P R . I M b A l E 0.95 r 1 0.50 T Y e 4 WE p B . T R L 2 B 140 u U D t U LB B B T F - E 0.90 T M O P Y E E
75 R D P W AT 75 5 L U N 0 A R 0.55
130 U
E e H - r ° O 0.85 T F u t P
N s E i
3 R 5 o Y E m R
P 0.80 1 4 120 d 0.60 U E e C
. t 0 R F a R i ° U
c E - T
o M S s
E 0.75 70 I s F R
O 70 a 0.65 110 % O U
0 M d T 9 S n F A a E
R 3 O 0.70 r
0 H i E a S 0.70 C
P y
1 N N
I 4 r I 3 M 100 5 d - . A E
8
f 0.65 R
% T E
0 o
8 G 0.75 . R T
)
65 b U N l y 65 I t r S i O e d S 90 i 0.60 P 0.80 p E
m u 2 R u t 5 W P B E H
% 0.85 0 - D R
1 c
7 i
3 f . ReturnSpace- Condition Air i Y 0.55 O
6 c 80 P 0.90 P e L 60 A p A 60 V S
H
r 0.95
T 0.50 o ( N 0% 1.00 E
6 O 70 I t 20 T 4 1 0 A 3 Q 0.45
R 55 . /
4 55 Y s T I
- - 50% Load SAT Q
% 0 60 D 0.40 I
5 =
M O U I 50 1 H 3 50 T
. A 15 2 0.35
50 R % 40 T
45 A 45 0.30 1 E 3 H
. 0 40 E
40 L % 40 35 0.25 0 B
3 I 1 2 S . 35 N 8 30 35 0.20 E
32 S 30 1 10 2 . 0% 30 6 2 0.15 20 25 IDITY 20 0.10 25 TIVE HUM 10% RELA 10 10 0.05 0 30 20 0 30 40 50 60 STANDARD AIR 70 80 90 100 110 115 DRY BULB TEMPERATURE - °F Chart by: HANDS DOWN SOFTWARE, www.handsdownsoftware.com
10 15 20 25 ENTHALPY - Btu per lb. of dry air and associated moisture Air System – Plenum Return 55 0.20 0.25 0.30 • Air Side Delta T increased. SENSIBLE HEAT RATIO = Qs / Qt
0.35 90 • Airflow decreased. 5 0 200 1.30
1 4 1.25 • . 190 Same Coil Capacity. 6 1 1 85 4 5 . . 85 8 0 1.20 180 0.40
e r 45 1.15 tu is o 170 m BAROMETRIC PRESSURE: 29.921 in. HG d 1.10 te 1 a 4 i . c 4 55 o s s F 160 1.05 a 0.45 ° d - 80 n E 80 a r R i U a T 1.00 y r A 150 d 40 R f E
o P R . I M b A l E 0.95 r 1 0.50 T Y e 4 WE p B . T R L 2 B 140 u U D t U LB B B T F - E 0.90 T M O P Y E E
75 R D P W AT 75 5 L U N 0 A R 0.55
130 U
E e H - r ° O 0.85 T F u t P
N s E i
3 R 5 o Y E m R
Outdoor Air P 0.80 1 4 120 d 0.60 U E e C
. t 0 R F a R i ° U
c E - T
o M S s
E 0.75 70 I s F R
O 70 a 0.65 110 % O U
0 M d T 9 S n F A a E
R 3 O 0.70 r
0 H i E a S 0.70 C
P y
1 N N
I 4 r I 3 M 100 5 d - . A E
8
f 0.65 R
% T E
0 o
8 G 0.75 . R T
)
65 b U N l y 65 I t r S i O e d S 90 i 0.60 P 0.80 p E
m u 2 R u t 5 W P B E H
% 0.85 0 - D R
1 c
7 i
3 f . Mixed Air: 25% OA i Y 0.55 O 6 c 80 P 0.90 P e L 60 A p A 60 V S
H
r 0.95
T 0.50 o ( N 0% 1.00 E
6 O 70 I t 20 Rm T Return Temperature T 40 1 A 3 Q 0.45
R 55 . /
4 55 Y s T I
LC Supply Air Temp Q
% 0 60 D 0.40 I
5 =
M O U I 50 1 H 3 50 T
. A 15 2 0.35
50 R % 40 T
45 A 45 0.30 1 E 3 H
. 0 40 E
40 L % 40 35 0.25 0 B
3 I 1 2 S . 35 N 8 30 35 0.20 E
32 S 30 1 10 2 . 0% 30 6 2 0.15 20 25 IDITY 20 0.10 25 TIVE HUM 10% RELA 10 10 0.05 0 30 20 0 30 40 50 60 STANDARD AIR 70 80 90 100 110 115 DRY BULB TEMPERATURE - °F Chart by: HANDS DOWN SOFTWARE, www.handsdownsoftware.com
10 15 20 25 ENTHALPY - Btu per lb. of dry air and associated moisture Face and Bypass Cooling Coil 55 0.20 0.25 0.30 • Airstream splits through coil. SENSIBLE HEAT RATIO = Qs / Qt
0.35 90 • Mixing of fully condition and 5 0 200 1.30
1 4 1.25 . 190 unconditioned air. 6 1 1 85 4 5 . . 85 8 0 1.20 180 0.40
e r 45 1.15 tu is o 170 m BAROMETRIC PRESSURE: 29.921 in. HG d 1.10 te 1 a 4 i . c 4 55 o s s F 160 1.05 a ° 0.45 d - 80 n E 80 a r R i U a T 1.00 y r A 150 d 40 R f E o P R . I M lb A E 0.95 r 1 0.50
T Y e 4 WE p B . T R L 2 B 140 u U D t U LB B B T F - E 0.90
T M O P Y E E
P 75 R D W AT 75 5 L U N 0 A R 130 0.55 U E e H - r ° O 0.85
T F u t N P
s E i
3 R 5 o Y E m R
P 0.80 1 4 120 d 0.60 U E e C
. t 0 R F a R i ° U c E - T
o M
S E s 0.75
70 I s F 70 R O a 0.65
% 110 O U
0 M d T 9 S n F A E a
R 3 O 0.70 r
0 H
i E a S C
0.70 1 P N y N I I
4 r
3 M 100 5 - d . A E
8
f 0.65
% R T E
0 o
8 G 0.75 . R Entering Cooling Coil T
) 65 b U N l
y 65 I t r S i O e S d i
90 P 0.60 p 0.80 E
m u 2 R t u 5 W P B E H
%
0 - 0.85 D R
1 7 c i
3 f Y O . i 0.55 c 6 P 80 0.90 P e L
60 A p A
60 V S H
r 0.95
T 0.50 o ( N 0% 6 E 1.00 O 2 70 I t 0 T 4 1 0 A
3 Q 0.45
55 . R / 4 55 Y s T
Leaving Cooling Coil I % Q
0 60 D 0.40 5 I =
M U O 50 1 I H
3 50 T 1 . 0.35 5 2 50 A R 0% 45 4 T 45 A 0.30
1 E 3 . H 0 40 40 E 0% 40 35 L 0.25 3 B 1 I
2 S 35 . 8 30 35 N 0.20 32 E S 1 10 30 2 . 0% 30 6 2 0.15 20 25 IDITY 20 0.10 25 TIVE HUM 10% RELA 10 10 0.05 0 30 20 0 30 40 50 60 STANDARD AIR 70 80 90 100 110 115 DRY BULB TEMPERATURE - °F Chart by: HANDS DOWN SOFTWARE, www.handsdownsoftware.com
10 15 20 25 ENTHALPY - Btu per lb. of dry air and associated moisture Min OA Cooling Coil 55 0.20 0.25 0.30 • Staged Coil Control SENSIBLE HEAT RATIO = Qs / Qt
0.35 90 • Cools and Dehumidifies OA 5 0 200 1.30
1 4 1.25 . 190 before Return Air 6 1 1 85 4 5 . . 85 8 0 1.20 • Provides dry supply air 180 0.40 e r 45 1.15 tu is o 170 m temperaturesBAROMETRIC PRESSURE: 29.921 in. HGat part load. d 1.10 te 1 a 4 i . c 4 55 o s s F 160 1.05 a ° 0.45 d - 80 n E 80 a r R i U a T 1.00 y r A 150 d 40 R f E o P R . I M lb A E 0.95 r 1 0.50
T Y e 4 WE p B . T R L 2 B 140 u U D t U LB B B T F - E 0.90
T M O P Y E E
P 75 R D W AT 75 5 L U N 0 A R 130 0.55 U E e H - r ° O 0.85
T F u t N P
s E i
3 R 5 o Y E m R
Outdoor Air P 0.80 1 4 120 d 0.60 U E e C
. t 0 R F a R i ° U c E - T
o M
S E s 0.75
70 I s F 70 R O a 0.65
% 110 O U
0 M d T 9 S n F A E a
R 3 O 0.70 r
0 H
i E a S C
0.70 1 P N y N I I
4 r
3 M 100 5 - d . A E
8
f 0.65
% R T E
0 o
8 G 0.75 . R T
) 65 b U N l
y 65 I t r S i O e S d i
90 P 0.60 p 0.80 E
m u 2 R t u 5 W P B E H
%
0 - 0.85 D R
1 7 c i
3 f Y O . i 0.55 c 6 P 80 0.90 P e L
60 A p A
60 V S H
r 0.95
T 0.50 o ( N 0% 6 E 1.00 O 2 Return Air 70 I t 0 T 4 1 0 A
3 Q 0.45
55 . R / 4 55 Y s T
Leaving Coil I % Q
0 60 D 0.40 5 I =
M U O 50 1 I H
3 50 T 1 . 0.35 5 2 50 A R 0% 45 4 T 45 A 0.30
1 E 3 . H 0 40 40 E 0% 40 35 L 0.25 3 B 1 I
2 S 35 . 8 30 35 N 0.20 32 E S 1 10 30 2 . 0% 30 6 2 0.15 20 25 IDITY 20 0.10 25 TIVE HUM 10% RELA 10 10 0.05 0 30 20 0 30 40 50 60 STANDARD AIR 70 80 90 100 110 115 DRY BULB TEMPERATURE - °F Chart by: HANDS DOWN SOFTWARE, www.handsdownsoftware.com
10 15 20 25 ENTHALPY - Btu per lb. of dry air and associated moisture Dedicated Outdoor Air Unit 55 0.20 0.25 0.30 • Total Energy Recovery SENSIBLE HEAT RATIO = Qs / Qt
0.35 90 • Integral exhaust fan 5 0 200 1.30
1 4 1.25 . 190 6 1 1 85 4 5 . . 85 8 0 1.20 180 0.40
e r 45 1.15 tu is o 170 m BAROMETRIC PRESSURE: 29.921 in. HG d 1.10 te 1 a 4 i . c 4 55 o s s F 160 1.05 a ° 0.45 d - 80 n E 80 a r R i U a T 1.00 y r A 150 d 40 R f E o P R . I M lb A E 0.95 r 1 0.50
T Y e 4 WE p B . T R L 2 B 140 u U D t U LB B B T F - E 0.90
T M O P Y E E
P 75 R D W AT 75 5 L U N 0 A R 130 0.55 U E e H - r ° O 0.85
T F u t N P
s E i
3 R 5 o Y E m R
Outdoor Air P 0.80 1 4 120 d 0.60 U E e C
. t 0 R F a R i ° U c E - T
o M
S E s 0.75
70 I s F 70 R O a 0.65
% 110 O U
0 M d T 9 S n F A E Exhaust Air a
R 3 O 0.70 r
0 H
i E a S C
0.70 1 P N y N I I
4 r
3 M 100 5 - d . A E
8
Entering Coil f 0.65
% R T E
0 o
8 G 0.75 . R T
) 65 b U N l
y 65 I t r S i O e S d i
90 P 0.60 p 0.80 E
m u 2 R t u 5 W P B E H
%
0 - 0.85 D R
1 7 c i
3 f Y O . i 0.55 c 6 P 80 0.90 P e L
60 A p A
60 V
- Return Air S H
r 0.95
T 0.50 o ( N 0% 6 E 1.00 O 2 70 I t 0 T 4 1 0 A
3 Q 0.45
55 . R LCC Supply Temp / 4 55 Y s T I % Q
0 60 D 0.40 5 I =
M U O 50 1 I H
3 50 T 1 . 0.35 5 2 50 A R 0% 45 4 T 45 A 0.30
1 E 3 . H 0 40 40 E 0% 40 35 L 0.25 3 B 1 I
2 S 35 . 8 30 35 N 0.20 32 E S 1 10 30 2 . 0% 30 6 2 0.15 20 25 IDITY 20 0.10 25 TIVE HUM 10% RELA 10 10 0.05 0 30 20 0 30 40 50 60 STANDARD AIR 70 80 90 100 110 115 DRY BULB TEMPERATURE - °F Chart by: HANDS DOWN SOFTWARE, www.handsdownsoftware.com
10 15 20 25 ENTHALPY - Btu per lb. of dry air and associated moisture Energy Recovery AHU 55 0.20 0.25 0.30 • Total Energy Recovery SENSIBLE HEAT RATIO = Qs / Qt
0.35 90 • 25% Outdoor air 5 0 200 1.30
1 4 1.25 . 190 6 1 1 85 4 5 . . 85 8 0 1.20 180 0.40
e r 45 1.15 tu is o 170 m BAROMETRIC PRESSURE: 29.921 in. HG d 1.10 te 1 a 4 i . c 4 55 o s s F 160 1.05 a ° 0.45 d - 80 n E 80 a r R i U a T 1.00 y r A 150 d 40 R f E o P R . I M lb A E 0.95 r 1 0.50
T Y e 4 WE p B . T R L 2 B 140 u U D t U LB B B T F - E 0.90
T M O P Y E E
P 75 R D W AT 75 5 L U N 0 A R 130 0.55 U E e H - r ° O 0.85
T F u t N P
s E i
3 R 5 o Y E m R
Outdoor Air P 0.80 1 4 120 d 0.60 U E e C
. t 0 R F a R i ° U c E - T
o M
S E s 0.75
70 I s F 70 R O a 0.65
% 110 O U
0 M d T 9 S n F A E a
R 3 O 0.70 r
0 H
i E a S C
0.70 1 P N y N I I
4 r
3 M 100 5 - d . A E
8 OA: Post ERU
f 0.65
% R T E
0 o
8 G 0.75 . R T
) 65 b U N l
y 65 I t r S i O e S d i
90 P 0.60 p 0.80 E
m u 2 R t u 5 W P B E H
%
0 Mixed Air - 0.85 D R
1 7 c i
3 f Y O . i 0.55 c 6 P 80 0.90 P e L
60 A p A
60 V S H
r 0.95
Return Air T 0.50 o ( N 0% 6 E 1.00 O 2 70 I t 0 T 4 1 0 A
3 Q 0.45
55 . R / 4 55 Y s T I % Q
0 60 D 0.40 5 I =
- SAT M U O 50 1 I H
3 50 T 1 . 0.35 5 2 50 A R 0% 45 4 T 45 A 0.30
1 E 3 . H 0 40 40 E 0% 40 35 L 0.25 3 B 1 I
2 S 35 . 8 30 35 N 0.20 32 E S 1 10 30 2 . 0% 30 6 2 0.15 20 25 IDITY 20 0.10 25 TIVE HUM 10% RELA 10 10 0.05 0 30 20 0 30 40 50 60 STANDARD AIR 70 80 90 100 110 115 DRY BULB TEMPERATURE - °F Chart by: HANDS DOWN SOFTWARE, www.handsdownsoftware.com
10 15 20 25 ENTHALPY - Btu per lb. of dry air and associated moisture High Latent Cooling AHU 55 0.20 0.25 0.30 • Space Design: 68°F & 35% RH SENSIBLE HEAT RATIO = Qs / Qt
0.35 90 • Chilled Water: 45°F 5 0 200 1.30
1 4 1.25 . 190 6 1 1 85 4 5 . . 85 8 0 1.20 180 0.40
e r 45 1.15 tu is o 170 m BAROMETRIC PRESSURE: 29.921 in. HG d 1.10 te 1 a 4 i . c 4 55 o s s F 160 1.05 a ° 0.45 d - 80 n E 80 a r R i U a T 1.00 y r A 150 d 40 R f E o P R . I M lb A E 0.95 r 1 0.50
T Y e 4 WE p B . T R L 2 B 140 u U D t U LB B B T F - E 0.90
T M O P Y E E
P 75 R D W AT 75 5 L U N 0 A R 130 0.55 U E e H - r ° O 0.85
T F u t N P
s E i
3 R 5 o Y E m R
Outdoor Air P 0.80 1 4 120 d 0.60 U E e C
. t 0 R F a R i ° U c E - T
o M
S E s 0.75
70 I s F 70 R O a 0.65
% 110 O U
0 M d T 9 S n F A E a
R 3 O 0.70 r
0 H
i E a S C
0.70 1 P N y N I I
4 r
3 M 100 5 - d . A E
8
f 0.65
% R T E
0 o
8 G 0.75 . R T
) 65 b U N l
y 65 I t r S i O e S d i
90 P 0.60 p 0.80 E
m u 2 R t u 5 W P B E H
%
0 - 0.85 D R
1 7 c i
3 f Y O . i 0.55 c 6 P 80 0.90 P e L
60 A p A
60 V S H
r 0.95
T 0.50 o ( N 0% 6 E 1.00 O 2 70 I t 0 T 4 1 0 A
3 Q 0.45
55 . R / 4 55 Y s
- Lvg Regen T I % Q
0 60 D 0.40 5 I =
M U O 50 1 I H
Lvg Cooling Coil3 50 T 1 . 0.35 5 2 50 A R 0%
Mixed Air Lvg Preheat T 45 4 45 A 0.30
1 E 3 . H 0 40 40 Return Air E Lvg Wheel 0% 40 35 L 0.25 3 B 1 I
2 S 35 . 8 30 35 N 0.20 32 E S 1 10 30 2 . 0% 30 6 2 0.15 20 25 IDITY 20 0.10 25 TIVE HUM 10% RELA 10 10 0.05 0 30 20 0 30 40 50 60 STANDARD AIR 70 80 90 100 110 115 DRY BULB TEMPERATURE - °F Chart by: HANDS DOWN SOFTWARE, www.handsdownsoftware.com
10 15 20 25 ENTHALPY - Btu per lb. of dry air and associated moisture Questions?
THANK YOU!
Jesse Fisher, PE [email protected]