HVAC COMPUTATIONS

Project: Office Headquarters Building

Location:

Atlanta, Georgia

Summer DB T2 =

92

Interior T1 =

76

Winter DB T3 =

22

Interior T4 =

72

Humidity Ratio W2 =

0.0160

Humidity W1 =

0.0102

COOLING LOAD

Degree Days =

1,589

Envelope

R

FACTOR

UNIT

QUANT

MEAS

T2-T1

BTUH

Roof

30.0

0.033

"U"

51,512

SF

16

27,473

Exterior Wall

19.0

0.053

"U"

62,230

SF

16

52,404

Exterior Glass

1.2

0.840

"U"

26,670

SF

16

358,588

Other -

-

"U"

SF

16

-

Solar

FACTOR

Additional Roof Gain

0.033

"U"

51,512

SF

55

94,439

N. Glass Exposure

6,668

SF

37

246,698

S. Glass Exposure

6,668

SF

111

740,093

E. Glass Exposure

6,668

SF

219

1,460,183

W. Glass Exposure

6,668

SF

219

1,460,183

Shading Credit

3,907,155

BTUH

-0.43

(1,680,077)

Interior

Ventilation Air (cfm/person)

20

latent

1.1

BTU/CFM

72,780

CFM

16

1,280,928

sensible

0.0058

W2-W1

72,780

CFM

4840

2,043,080

People

550

BTUH/PER

3,639

PER

2,001,450

Lighting & power

3

WATT/SF

244,995

SF

3.41

734,985

Computer room

10

WATT/SF

14,000

SF

3.41

140,000

Other -

WATT/SF

SF

3.41

-

TOTAL BTUH =

8,960,426

TONS =

747

Equivalent Electricity =

KWH/YR =

5,010,481

HEATING LOAD

Degree Days =

3,095

Envelope

FACTOR

UNIT

QUANT

MEAS

T4-T3

BTUH

Roof

0.033

"U"

51,512

SF

50

85,853

Exterior Wall

0.053

"U"

62,230

SF

50

163,763

Exterior Glass

0.840

"U"

26,670

SF

50

1,120,588

Other

-

"U"

-

SF

50

-

RATE

Infiltration

1.1

BTU/LF

26,670

LF

50

1,466,850

Ventilation

1.1

BTU/CFM

72,780

CFM

50

4,002,900

TOTAL BTUH =

6,839,955

MBH =

6,840

Equivalent Electricity =

KWH/YR =

3,464,992

Equivalent Gas =

CCF/YR =

140,662