UFC 3-400-02

28 FEBRUARY 2003

2-10

example of Data Set Page 13. Data Set Page 13 consists of charts summarizing a site's

mean heating and cooling degree days.

2-10.1

2-10.1.1

multiplying the number of hours that the outdoor temperature is above the base

temperature of 65 F (18 C) times the number of degrees of that temperature

difference. For example, if 1 hour was observed at a temperature of 78 F, that

observation adds 13 degree-hours to the annual total. The sum of the degree-hours is

divided by 24 to yield degree-days.

2-10.1.2

similarly, against the base temperature of 65 F, so a 1-hour outside temperature

observation of 62 F adds 3 degree-hours to the annual total. Heating degree-days are

summed separately from the cooling degree-days. Heating and Cooling degree-hours

do not cancel each other out, since both heating and cooling conditions may occur over

the course of a given day.

2-10.1.3

added to the AFCCC W eb site to include the cooling degree-days based upon a base

temperature of 50 F. This file is located on the Engineering W eather Data page under

the Standard EW D Package file. This data is intended to allow selection of the proper

Building Envelope Requirements table from within ASHRAE/IESNA Standard 90.1 of

2001 for energy conservation design. The cooling degree-days based on 65 F

tabulated and graphed here are historically used to estimate loads as suggested in

paragraph 2-10.2 below.

2-10.2

and sensible cooling loads on the building envelope. Degree-day loads can be used to

estimate the annual energy consumption of a building, provided that the loads from

ventilation and infiltration air are also considered (see paragraph 2-11).

27