6
Preliminary Load Calculations
6.1.0 Introduction
6.1.1 Prescriptive Unit Lighting Power Allowance (ULPA) (W/ft2
), Gross Lighted Area of Total Building
6.1.2 Typical Appliance/General-Purpose Receptacle Loads (Excluding Plug-In-Type A/C and Heating Equipment)
6.1.3 Typical Apartment Loads
6.1.4 Typical Connected Electrical Load for Air Conditioning Only
6.1.5 Central Air Conditioning Watts per SF, BTUs per Hour per SF of Floor Area, and SF per Ton of Air Conditioning
6.1.6 All-Weather Comfort Standard Recommended Heat-Loss Values
6.1.7 Typical Power Requirement (kW) for High-Rise Building Water Pressure–Boosting Systems
6.1.8 Typical Power Requirement (kW) for Electric Hot Water–Heating System 6.1.9 Typical Power Requirement (kW) for Fire Pumps in Commercial
Buildings (Light Hazard)
6.1.10 Typical Loads in Commercial Kitchens
6.1.11 Comparison of Maximum Demand
6.1.12 Connected Load and Maximum Demand by Tenant Classification
6.1.13 Factors Used in Sizing Distribution-System Components
6.1.14 Factors Used to Establish Major Elements of the Electrical System Serving HVAC Systems
6.1.15 Service Entrance Peak Demand (Veterans Administration)
6.1.16 Service Entrance Peak Demand (Hospital Corporation of America)
6.1.0
Introduction
The following tables are provided to assist the user in estimating preliminary loads for various building types. Considerable judgment should be used in the application of these data. Power densities typically are given in watts per square foot (W/ft2
) or volt-amperes per square foot (VA/ft2
) and are used interchangeably because unity power factor is assumed for preliminary load calculations.
6.1.1
Prescriptive Unit Lighting Power Allowance
(ULPA) (W/ft
2), Gross Lighted Area of Total Building
TABLE 6.1.1
TABLE 6.1.2
6.1.2
Typical Appliance/General-Purpose
Receptacle Loads (Excluding Plug-In-Type
A/C and Heating Equipment)
6.1.3
Typical Apartment Loads
TABLE 6.1.3
TABLE 6.1.4
6.1.4
Typical Connected Electrical
Load for Air Conditioning Only
6.1.5
Central Air Conditioning Watts per SF,
BTUs per Hour per SF of Floor Area, and
SF per Ton of Air Conditioning
TABLE 6.1.5
TABLE 6.1.6
6.1.6
All-Weather Comfort Standard
6.1.8
Typical Power Requirement (kW)
for Electric Hot Water–Heating System
TABLE 6.1.7
TABLE 6.1.8
TABLE 6.1.9
6.1.7
Typical Power Requirement (kW) for
High-Rise Building Water Pressure–Boosting Systems
6.1.9
Typical Power Requirement (kW) for Fire
Pumps in Commercial Buildings (Light Hazard)
(From IEEE Std. 241-1990. Copyright 1990 IEEE. All rights reserved.)
6.1.10
Typical Loads in Commercial Kitchens
TABLE 6.1.10
TABLE 6.1.11
Note: As an alternative to the preceding table, you may use 25 W/ft2 for commercial kitchens using natural gas for cooking or 125 W/ft2 for electric cooking. The applicable square footage in calculating kitchen floor area should include cooking and preparation, dishwashing, storage, walk-in refrigerators and freezers, food serving lines, tray assembly, and offices.
6.1.11
Comparison of Maximum Demand
6.1.12
Connected Load and Maximum
Demand by Tenant Classification
TABLE 6.1.12
TABLE 6.1.13
6.1.13
Factors Used in Sizing
Distribution-System Components
6.1.14
Factors Used to Establish Major Elements of
the Electrical System Serving HVAC Systems
TABLE 6.1.14
TABLE 6.1.15
Note: For a primary cooling system comprised of electrical centrifugal chillers, chilled water pumps, condenser water pumps, and cooling tower fans, a factor of 1.7 kVA/ton provides a good estimate.
(From IEEE Std. 602-1996. Copyright 1996 IEEE. All rights reserved.)
