Winter design conditions

Use Table B-l in the textbook or Table 1A of ASHRAE Fundamental Handbook Chapter26.

The 99.6% and 99% indicate the risk level desired. When 99% is selected, it means the outdoor temperatures have been equaled or exceeded by 99% of the total number of hours in a year (8760 hrs).

99.6% (0.4%) ~ 35 hrs 99.0% (1.0%) ~ 88 hrs

98.0 (2.0%) ~ 175 hrs

95.0 (5.0%)-438 hrs

Design conditions — Column 2 Wind — Column 3

Peak load for infiltration — Columns 4 and 5

ASHRAE Handbook 1997 and the textbook use annual percentiles of 99.6% and 99%.

Design rule of thumb: design outdoor relative humidity in winter 60%

Posted in Fundamentals of Heating. Ventilating, and Air-Conditioning


Добавить комментарий

Ваш e-mail не будет опубликован. Обязательные поля помечены *