re: snow architecture - ideas needed
31 may 2002
chris f. wrote:
>...check out this link before reading any further:
>i'm the author of this site, and the "architect" behind these projects.
>forts #18 and 19, in particular, show just what can actually be done with
>snow under the right circumstances. but there is still much room for
>improvement. the biggest problem we have right now is overcoming the
>occasional warm-ups, which might last anywhere from 6 to 48 hours or more.
>such thaws completely destroyed many early forts, later ones survived but
>often with considerable damage...
>covering these structures with tarps has helped reduce the effects of rain,
>but because of their size, it's becoming harder and more awkward to create
>tarps large enough to cover the entire structures...
>so what should we do? move north? i figure some of you guys must
>have a few ideas. if not for heat and rain, these forts would have
>almost no limit for size and complexity.
how about enclosing the snow in a commercial plastic film greenhouse
that works like an icehouse? a quonset shape, say 30'x100', with 3
layers of plastic film over semicircular pipe hoops on 4' centers.
the space between the outer layers might be automatically filled with
tiny cold soap bubble foam for insulation (using a shop vac to pump air
into 2 100'x2" pipes with holes under a few inches of 10% sodium laurel
sulfate solution in a plastic film fold near the ground) when the outdoor
temp is greater than 32 f, and the space might be collapsed to make ice
or snow by spraying water from a 100' overhead indoor pipe when the temp
is less than 32 f.
when the outer layers are foamed, the space between the inner layers
might be filled with 32 f air from a blower that melts a "sacrificial
snowpile" that protects the forts inside.
here's a basic simulation using nrel's "typical meteorological year"
data for philadelphia, assuming usr36 insulation when the layers are
foamed and r1 when they are not. if it works in phila, it ought to
work in canada :-)
10 open "fandat" for input as #1
20 for d=1 to 365'day
30 for h=1 to 24'hour
40 line input#1, s$'input a line from tmy2 file
50 temp=val(mid$(s$,8,5))'outdoor temp (f)
60 if temp<32 goto 70 else goto 90
70 snow=snow+(32-temp)/144'accumulate snow (pounds)
80 goto 110
90 snow=snow-(temp-32)/36/144'melt snow (pounds)
100 if snow < 0 then snow = 0'eliminate negative snow
110 next h
120 if d<4 or d> 362 or d>182 and d<186 then print s$,snow'snapshots
130 next d
140 close 1
m/d/h temp rh net snow
010124 12.92 053 2.3125
010224 19.04 051 4.205
010324 26.96 060 5.293751
starting with no snow, we've made 5.29 pounds per square foot of
plastic film by midnight on january 3rd...
070224 71.06 057 30.31894
070324 64.94 070 30.13144
070424 62.96 081 29.94667
slowly melting 30 psf at midnight in july...
122924 28.94 066 17.48907
123024 26.06 066 18.08081
123124 41.00 089 18.50223
by new year's eve we have a net gain of 18.5 pounds per square foot :-)