APPENDIX 7A. INTERNAL LOADS SCHEDULES AND PART-LOAD 

PERFORMANCE CURVES 

LIST OF TABLES 

Table 7A.1 Occupancy, Lighting and Plug Loads Schedules..................................... 7A-1 

Table 7A.2 CAC and CHP Performance Curves Used in Small Office Modeling..... 7A-2 

7A-i 

7A-1
 

APPENDIX 7A. INTERNAL LOADS SCHEDULES AND PART-LOAD PERFORMANCE C

Table 7A.1. Occupancy, Lighting and Plug Loads Schedules 

Schedule Day of 

Week 

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 

Lighting (1.0 W/sf) 

Weekday 0.18 0.18 0.18 0.18 0.18 0.23 0.23 0.42 0.90 0.90 0.90 0.90 0.80 0.90 0.90 0.90 0.90 0.61 0.42 

Sat 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18 

Sun, Hol, Other 

0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18 

Plug Equipment (0.63 W/sf) 

Weekday 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.50 1.00 1.00 1.00 1.00 0.94 1.00 1.00 1.00 1.00 0.50 0.20 

Sat 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 

Sun, Hol, Other 

0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 

Occupancy Weekday 0.00 0.00 0.00 0.00 0.00 0.00 0.11 0.21 1.00 1.00 1.00 1.00 0.53 1.00 1.00 1.00 1.00 0.32 0.11 

Sat 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Sun, Hol, Other 

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Heating Setpoint 

Weekday 60.0 60.0 60.0 60.0 60.0 60.0 65.0 70.0 70.0 70.0 70.0 70.0 70.0 70.0 70.0 70.0 70.0 70.0 70.0 

Sat 60.0 60.0 60.0 60.0 60.0 60.0 60.0 60.0 60.0 60.0 60.0 60.0 60.0 60.0 60.0 60.0 60.0 60.0 60.0 

Sun, Hol, Other 

60.0 60.0 60.0 60.0 60.0 60.0 60.0 60.0 60.0 60.0 60.0 60.0 60.0 60.0 60.0 60.0 60.0 60.0 60.0 

Cooling Setpoint 

Weekday, 85.0 85.0 85.0 85.0 85.0 85.0 80.0 75.0 75.0 75.0 75.0 75.0 75.0 75.0 75.0 75.0 75.0 75.0 75.0 

Sat 85.0 85.0 85.0 85.0 85.0 85.0 85.0 85.0 85.0 85.0 85.0 85.0 85.0 85.0 85.0 85.0 85.0 85.0 85.0 

Sun, Hol, Other 

85.0 85.0 85.0 85.0 85.0 85.0 85.0 85.0 85.0 85.0 85.0 85.0 85.0 85.0 85.0 85.0 85.0 85.0 85.0 

Fan Operation and Ventilation 

Weekday, 0.0 0.0 0.0 0.0 0.0 0.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 

Sat 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 

Sun, Hol, Other 

0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 

Infiltration Weekday, 1.00 1.00 1.00 1.00 1.00 1.00 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 

Sat, 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 

Sun, Hol, Other 

1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 

Hot Water Weekday, 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.27 0.55 0.64 0.64 0.82 1.00 0.91 0.55 0.55 0.73 0.37 0.37 

Sat, 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 

Sun, Hol, Other 

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 
Table 7A.2. CAC and CHP Performance Curves Used in Small Office Modeling 

Type Performance Curve 

Equation Curve Coefficients 

a b c d 

CAC Total Cooling Capacity Function of Temperature Curve 

EDBWBfEDBe

COOL EDBdWBcWBbaFTCAP

××+×+

×+×+×+=−−

2 

2 

1.186036 -0.06799 0.003167 -0.00902 

Total Cooling Capacity Function of Flow Fraction Curve 

FF 2 COOL cFFbaFFCAP ×+×+=−−

0.63751 0.409767 -0.12055 NA 

Energy Input Ratio Function of Temperature Curve 

EDBWBfEDBeEDBd

COOL WBcWBbaFTEIR

××+×+×+

×+×+=−−

2 

2 

-0.43891 0.145182 -0.00394 -0.02064 

Energy Input Ratio Function of Flow Fraction Curve 

FF 2 COOL cFFbaFFEIR ×+×+=−−

1.54819 -0.49832 0.204972 NA 

Cooling Part Load Fraction Correlation Curve 

PLR2 COOL cPLRbaPLREIR ×+×+=−−

0.771 0.229 0.0 NA 

PTHP Heating Capacity Function of Temperature Curve 

DB2 HEAT cDBbaFTCAP ×+×+=−−

0.691549 0.031304 0.000501 NA 

Heating Capacity Function of Flow Fraction Curve 

DB2 HEAT cDBbaFFCAP ×+×+=−−

1.014278 -0.16365 0.149368 NA 

Heating Energy Input Ratio Function of Temperature Curve 

2 3 HEAT ×+×+×+=−− DBcDBcDBbaFTEIR

0.829204 0.000697 0.000779 -0.00320 

Heating Energy Input Ratio Function of Flow Fraction Curve 

FF 2 HEAT cFFbaFFEIR ×+×+=−−

1.40347 -0.51017 0.106692 NA 

Heating Part Load Fraction Correlation Curve 

PLR2 HEAT cPLRbaFPLREIR ×+×+=−−

0.771 0.229 0.0 NA 

7A-2
 
 

 

 

 

 

Where: 

COOL − CAP − FT = Total Cooling Capacity Function of Temperature, 

COOL −CAP − FF = Total Cooling Capacity Function of Flow Fraction Curve, 

COOL − EIR − FT = Energy Input Ratio Function of Temperature, 

COOL − EIR − FF = Energy Input Ratio Function of Flow Fraction, 

COOL − EIR − FPLR = Total Cooling Part Load Fraction Correlation Curve Name, 

HEAT − CAP − FT = Heating Capacity Function of Temperature Curve Name, 

HEAT −CAP − FF = Heating Capacity Function of Flow Fraction Curve Name, 

HEAT − EIR − FT = Heating Energy Input Ratio Function of Temperature Curve Name, 

HEAT − EIR − FF = Heating Energy Input Ratio Function of Flow Fraction Curve 

Name, 

HEAT − EIR − FPLR = Heating Part Load Fraction Correlation Curve Name, 

WB = entering coil wet-bulb temperature (° F), 

DB = outside dry-bulb temperature (° F), 

EDB = entering coil dry-bulb temperature (° F), and 

PLR = Part Load Ratio (cooling load/steady-state capacity). 

Normalized performance curves for the CAC and CHP condensing units were developed 

based on manufacturers catalog data for Carrier CAC (50ES036) for cooling performance and 

Carrier CHP (50VT036) equipment for heating performance.1,2 Equations are in formats 

accepted for use in the EnergyPlus simulation tool input files (*. idf) files for each simulation 

run. Part load fraction correlation curves were based on commercial performance data used in the 

DOE Benchmark model for cooling part-load performance degradation. Nomenclature used for 

left hand side of each performance curve equation based on DOE2.1E descriptors for these 

parameters and is not normally found in the EnergyPlus documentation. 

1

 Carrier performance data for CAC. (Last accessed April 2009.) 

http://www.docs.hvacpartners.com/idc/groups/public/documents/techlit/50es-02pd.pdf

2

 Carrier performance data for CAC. (Last accessed April 2009.) 

http://www.docs.hvacpartners.com/idc/groups/public/documents/techlit/50vt-01pd.pdf 

7A-3