Chapter hvac engineering Fundamentals: Part 1 Introduction

3.4
Design Criteria
The first step in any load calculation is to establish the design criteria
for the project. These data should be listed on standard forms, such
as those shown in Figs. 3.1, 3.2, and 3.3, and are needed for either
manual or computer calculations.
For manual calculations, some specific times of day must be as-
sumed because it is impractical to calculate manually for every hour
of occupancy. Due to solar effects, maximum loads in exterior zones
depend on exposure—in a typical office building, east-facing zones
peak at about 10 a.m. to noon, south-facing at noon to 2 p.m., and
west- and north-facing at 3 to 6 p.m., sometimes later. Because solar
factors for south-facing glass are greater in winter than in summer, a
Design Procedures: Part 1
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