MIL-HDBK-1011/2
APPENDIX D (continued)
1.3.1
Results of the Climate Analysis. The results of the climate
analysis are shown on the Climate Analysis Summary Worksheet (Figure D-11). In
the Kaneohe Bay climate, ventilation is the most suitable strategy for cooling
(Step 2). On an annual basis, comfort can be achieved using 197 fpm 1.0 m/sec
ventilation for 99.9 percent of the year, and using 98 fpm (0.5 m/sec)
ventilation for 96.6 percent of the year. No mechanical air conditioning
(Step 3) or heating system (Step 5) is required, and the building envelope
does not need to be infiltration resistant (Step 4).
If 0.5 m/sec ventilation is used, only September will have a
significant (over 14 percent) uncomfortable period (Step 6). Since smaller
window areas will be permitted if 0.5 m/sec ventilation is used (as opposed to
1.0 m/sec), this example will use 0.5 m/sec ventilation as the cooling
strategy with ceiling fans providing additional ventilation during September
and any times when the outside wind speed is too low for comfort.
1.4
Window Sizing Procedure. Since this is an existing building which
is being modified, this example uses the window sizing procedure to check the
adequacy of the proposed window sizes (Appendix C, para. 1.1.2) rather than to
predict the sizes that should be incorporated into the design. Both of these
functions of the window sizing procedure are the same up to Step 15.
(1)
Required air velocity rate.
V=
98.5
fpm =
0.5 m/sec
From Climate Analysis
(2)
Cross-sectional area of the room, CS
Height of room, H
H =
8.5 ft
Width of room across flow, W
W =
9.5 ft
80.75ft2
CS = H * W
CS =
(3)
Required airflow rate, CFM.
CFM = V x CS
CFM =
7953.8cfm
(4)
Building location =
Kaneohe Bay, HI
(city)
Weather Station location = Kaneohe Bay, HI
From: Climate Analysis--examine worst two
naturally ventilated months separately.
Design months:
Sept. / August
Prevailing wind direction for month, WD.
WD =
ENE
/
ENE
(a) OPTION 1: MOS Part E--"Temperature vs. Wind Direction". Pick
predominant wind direction associated with the 82deg.F to
86deg.F
band for the month.
(b) OPTION 2: If no SMOS exists for the location, use RUSSWO Part
C--"Surface Winds." Pick predominant wind direction for month.
(6)
Wind speed for month, WS.
WS = 9.5 kn = 10.3 kn
From: SMOS or RUSSWO Part C--"Surface Winds."
Pick mean wind speed corresponding to direction
chosen in Step 5 for the month.
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