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Heating Load Estimator

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Input Parameters

Unit System

Auto-calculated from Area × Height

Additional calculation parameters

CSV Data Import/Export

Includes hourly profiles, temperature sensitivity, and parameter variations

Calculation Results

Total Heating Load

104,300
Transmission BTU/hr
7,560
Infiltration BTU/hr
111,860
Total BTU/hr

Load Breakdown

Transmission Load104,300 BTU/hr
Wall Transmission16,800 BTU/hr
Roof Transmission21,000 BTU/hr
Floor Transmission52,500 BTU/hr
Window Transmission14,000 BTU/hr
Infiltration Load7,560 BTU/hr(7%)

System Sizing

Required Capacity: 112 MBH
(111,860 BTU/hr)
Electric Heat Equivalent: 32.8 kW

Load Breakdown

Transmission vs Infiltration

Load Distribution

Load Density Comparison

Percentage Contribution

Detailed Analysis & Recommendations

Load Density Analysis

Total Load Density:74.57 BTU/hr/sq ft
Transmission Load Density:69.53 BTU/hr/sq ft
Infiltration Load Density:5.04 BTU/hr/sq ft

System Recommendations

• Commercial unit heater or rooftop unit

Performance Metrics

93%
Transmission Ratio
7%
Infiltration Ratio
70
Temperature Difference
0.50
Overall U-Value

Heating Load Calculation Steps

1

Calculate Temperature Difference

Formula:
ΔT=Tindoor−Toutdoor\Delta T = T_{indoor} - T_{outdoor}
Calculation:
ΔT=70−0\Delta T = 70 - 0
Result:
70 °F70 \text{ °F}
2

Calculate Wall Transmission Load

Formula:
Qwall=Awall×Uwall×ΔTQ_{wall} = A_{wall} \times U_{wall} \times \Delta T
Calculation:
Qwall=800×0.3×70Q_{wall} = 800 \times 0.3 \times 70
Result:
16800 BTU/hr16800 \text{ BTU/hr}
3

Calculate Roof Transmission Load

Formula:
Qroof=Aroof×Uroof×ΔTQ_{roof} = A_{roof} \times U_{roof} \times \Delta T
Calculation:
Qroof=1500×0.2×70Q_{roof} = 1500 \times 0.2 \times 70
Result:
21000 BTU/hr21000 \text{ BTU/hr}
4

Calculate Floor Transmission Load

Formula:
Qfloor=Afloor×Ufloor×ΔTQ_{floor} = A_{floor} \times U_{floor} \times \Delta T
Calculation:
Qfloor=1500×0.5×70Q_{floor} = 1500 \times 0.5 \times 70
Result:
52500 BTU/hr52500 \text{ BTU/hr}
5

Calculate Window Transmission Load

Formula:
Qwindow=Awindow×Uwindow×ΔTQ_{window} = A_{window} \times U_{window} \times \Delta T
Calculation:
Qwindow=200×1×70Q_{window} = 200 \times 1 \times 70
Result:
14000 BTU/hr14000 \text{ BTU/hr}
6

Calculate Total Transmission Load

Formula:
Qtransmission=Qwall+Qroof+Qfloor+QwindowQ_{transmission} = Q_{wall} + Q_{roof} + Q_{floor} + Q_{window}
Calculation:
Qtransmission=16800+21000+52500+14000Q_{transmission} = 16800 + 21000 + 52500 + 14000
Result:
104300 BTU/hr104300 \text{ BTU/hr}
7

Calculate Infiltration Load

Formula:
Qinfiltration=ACHadjusted×V×ΔT×0.018Q_{infiltration} = ACH_{adjusted} \times V \times \Delta T \times 0.018
Calculation:
Qinfiltration=0.50×12000×70×0.018Q_{infiltration} = 0.50 \times 12000 \times 70 \times 0.018
Result:
7560 BTU/hr7560 \text{ BTU/hr}
8

Calculate Total Heating Load

Formula:
Qtotal=Qtransmission+Qinfiltration+QventilationQ_{total} = Q_{transmission} + Q_{infiltration} + Q_{ventilation}
Calculation:
Qtotal=104300+7560+0Q_{total} = 104300 + 7560 + 0
Result:
111860 BTU/hr111860 \text{ BTU/hr}