
re: pjm  founder
14 sep 2004
wrote:
> but, but, but .... what about my plans to take over the world
>? i thought a usenet group would be as good a place to start as any
>....
fight those evil thoughts. let goodness and mercy envelop your soul.
pretend that people are cats.
> nick, get help. psychiatric help. you're getting worse and
>worse as time goes on, and eventually you're going to find yourself
>living out in a cabin in the woods, sending packages to people.
i do that already, but there are easier ways to get your face on a stamp.
you can buy a sheetful for a mere $20, if you do the graphics online...
cheers,
nick
work in progress...
20 ta=84'ambient temp (f)
30 wa=.0185'ambient humidity ratio
40 pa=29.921/(.62198/wa+1)'ambient vapor pressure ("hg)
50 tdp=9621/(17.863log(pa))460'dew point temp (f)
60 twbl=460+(ta+tdp)/2'initial twb estimate (r)
70 twb=9621/(22.468log(ta+460+100*patwb))'wet bulb temp (r)
80 if abs(twbtwbl)/twb >.01 then twbl=twb:goto 70
90 twb=twb460'wet bulb temp (f)
100 carea=200'clothing area (ft^2, 1 side)
110 gc=1.5*2*carea'clothingair conductance (btu/hf)
120 dryrate=(tatwb)*gc'drying rate (btu/h)
130 ww=12'water weight (pounds)
140 drytime=1000*ww/dryrate'drying time (h)
150 print 0,ta,twb,tdp,drytime
170 fullsun=250'solar power (btu/ft^2h)
180 sunpower=.9*16*16*fullsun'sun into greenhouse (btu/h)
190 gg=256'greenhouse thermal conductance (btu/h)
200 rho=.075'nominal air density (lb/ft^3)
210 lat=1000'latent heat (btu/lb)
220 f1=60*lat*rho'factor
230 f2=60*lat*rho/gc'factor
240 tar=ta+460'ambient temp (r)
250 for c=100 to 200 step 20'greenhouse airflow (cfm)
260 alpha=sunpower+gg*tar+wa*c*(f1+f2*(c+gg))+tar*c
270 beta=gg+c
280 gamma=c*(f1+f2*(c+gg))
290 twbl=100+460'twb initial est (r)
300 wi=(alphabeta*twbl)/gamma'greenhouse humidity ratio
310 twb=9621/(22.468log(ta+460+2992.1/(.62198/wi+1)twb))
320 if abs(twbtwbl)/twb >.01 then twbl=twb:goto 300
330 twb=twb460'wet bulb temp (f)
340 tg=twb+f2*c*(wiwa)'greenhouse air temp (f)
350 dryrate=(tgtwb)*gc'drying rate (btu/h)
360 drytime=1000*ww/dryrate'drying time (h)
370 pi=29.921/(.62198/wi+1)'greenhouse vapor pressure ("hg)
380 tdp=9621/(17.863log(pi))460'greenhouse dew point (f)
390 print c,tg,twb,tdp,drytime
400 next
airflow dry bulb wet bulb dew point drying time
free 84 f 77.61066 f 74.23621 f 3.130212 hours
100 cfm 161.7445 114.8843 118.6882 .4268011
120 157.2436 110.5703 114.3571 .4285108
140 157.7107 109.005 111.8636 .4106299
160 154.7812 106.2406 108.9128 .4120266
180 152.2271 103.9094 106.3851 .4139266
200 149.969 101.9149 104.1895 .4161981
the first is the clothesline. why is the wet bulb less than the dew point?

