```X-Message-Number: 2026
Date: Thu, 25 Mar 93 14:29:15 CST
From: Brian Wowk < var s1 = "wowk"; var s2 = "ccu.UManitoba.CA"; var s3 = s1 + "@" + s2; document.write("<a href='mailto:" + s3 + "'>" + s3 + "</a>"); >
Subject: CRYONICS Freeman Model

Tim Freeman's idea for modelling the edges and corners of the
room as sections of cylinders and spheres is exceedingly clever.  I
immediately proceeded to implement it and discovered that the heat
flow in the limit of very small radii for both spheres and cylinders
is zero!  Oh well.

Current Summary of Heat Flow Calculations for 5m x 5m x 3m Room with
1m Trymer Insulation:

Flat Wall Approximation, Uniform Room-Temp K Value:

347 watts, 128 liters LN2 per day.

Flat Wall Approximation, K Proportional to sqrt(T):

297 watts, 110 liters LN2 per day.

Spherical Room (R1=2.17m), K Proportional to sqrt(T):

434 watts, 160 liters LN2 per day

or 500 watts, 180 liters LN2 per day
if I take inner surface area as 4*pi*R1^2
instead of 110m^2 of the actual room.

I am satisfied for the time being that I have the heat flow
calculations under control.  I think 200 liters per day is a good
estimate for the LN2 use.  Besides, I have a thesis to write too!

--- Brian Wowk

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