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-----Original Message-----
From: phys-l-bounces@carnot.physics.buffalo.edu [mailto:phys-l-
bounces@carnot.physics.buffalo.edu] On Behalf Of James Mackey
Sent: Wednesday, August 24, 2011 10:42 PM
To: Forum for Physics Educators
Subject: Re: [Phys-l] cooling hints
Years ago, during 70s energy crisis (la plus sa change, la meme la
chose!) I
did a simulation in lab with a variac and a homemade AC box that was
connected to a simple immersion heater placed in a an insulated beaker
and
an uninsulated beaker. Part of the lab was to compare energy
consumption
between complete AC turn off and reducing the set point temperature. A
complete cycle was run to simulate a constant AC setting, a temp
reduction
setting and a complete AC off by starting all runs at a fixed
temperature
and running through the 3 cycles for fixed times and then returning to
the
initial temperature. Invariably, minimum energy consumption for the
complete cycle was lowest with the complete turn off cycle. Probably
not
terribly applicable to today's units, but students found it very
surprising. Most students believed you used more energy to "catch up"
if
you turned off the heater.
James Mackey
On Wed, Aug 24, 2011 at 3:31 PM, John Clement <clement@hal-pc.org>
wrote:
I know someone who was working for the Army and in the winter theyused to
open the windows to combat the overheating of their work space. Butduring
one year when there was a jump in energy prices the Army sealed thewindows
shut to prevent this. Why they didn't just turn down the heat is an_______________________________________________
unsolved mystery. So the employees found they could have comfort by
turning
on the AC.
John M. Clement
Houston, TX
Ah! Bitten by the "Law" of Unintended Consequences.
_______________________________________________
Forum for Physics Educators
Phys-l@carnot.physics.buffalo.edu
https://carnot.physics.buffalo.edu/mailman/listinfo/phys-l
Forum for Physics Educators
Phys-l@carnot.physics.buffalo.edu
https://carnot.physics.buffalo.edu/mailman/listinfo/phys-l