HVAC at CSU
by Zube (Zube@cs.colostate.edu)  
Created:  Jun 6, 2008
Updated:  Jun 6, 2008
http://www.cs.colostate.edu/~dzubera/hvac.txt

[Additions, suggestions, corrections or thoughtful discussion always welcome.]

This is an odd topic, but I find it interesting even though it is
related to HVAC (Heating, Ventilation and Air Conditioning).

The thermostat in my office has two dials, one for heat and one for
cooling.

Which one am I supposed to use?  It's hard to tell.

The only way to know which one is active is to move the dial a bit and
see if it hisses like a goose protecting its goslings.  If it does,
that's the active one.  Because only one is active, my temperature
choices are limited.  The building provides either heating or cooling,
but never both at the same time.  So if it is a hot day and the
building is being cooled, I can turn off the cooling but I can't get
any heat and vice-versa.

During the spring/fall months, swings in temperature cause the building
to be cooled during the day yet heated at night.  This would not matter
if the heat dial was active when heat was available and the cooling
dial was active when cooling was available, but that is not always the
case.

Here is a typical scenario in my building:

1) hot day, cooling available, so I turn the cooling dial down to 60
2) my office is cooled very nicely, even with servers running
3) during the night, the building switches over to heat, but the cooling
   dial is still the active one
4) hot air pours into the room and it's 90 or so when I get in the next 
   morning

Because of this design, during the spring/fall months, every night before 
going home I must set both dials to "off", meaning the cooling dial to 85 
and the heating dial to 55.

No grand conclusion, just a guess that every possible expense was spared
in the choice of an HVAC system for my building.