HISTORIC ST. AUGUSTINE PRESERVATION BOARD
TO: Marsha Chance & David Scott
FROM: Bob Steinbach S
SUBJECT: De Mesa Air Conditioning System
DATE: June 2, 1988
The system consists of three major parts:
1. Water supply pump, located behind fence next to the rear
door of the Greek Shrine. This pump draws its water from an
artesian well which is located under the steel plate next to the
rear gate to De Mesa.
If, for some reason air gets into the suction side of the
pump, it will air lock and begin to cycle on and off. Since it
is not pumping any water, the bearing and impeller are not being
cooled. If left to cycle, it will burn the pump up.
There is a switch next to the pump which will turn it off.
There is also a hose bib on the discharge side which can be used
to bleed the system of any residual air.
2 & 3. The other two major components of the system are the
compressor/evaporator units located in the attic. There is one
for each floor. These units rely on the water from the well to
cool the refrigerant. If the water supply is interrupted, the
compressors will overheat and a safety switch will turn them off.
They can be restarted by simply turning the units off and then
back on at the thermostats, after the compressors cool down, even
if the water supply is not restored. This cycling will
eventually cause the compressors to burn up. Since it costs
approximately $1500 apiece to replace them, it is important that
this cycling is not allowed to occur.
The only sure way to determine if water is flowing through
the units is to go up in the attic and listen for water running
through the discharge piping while the compressors are running,
since there are solenoid valves on the discharge side which are
only open at that time.
If the pump is cycling normally, ie. continues to run
constantly when the units are demanding water, and then shuts off
and maintains a constant pressure when the units are off, you can
assume the system is operating normally, unless it fails to heat
or cool. Should this occur, the best course of action is to turn
the systems off at the thermostat and call David Scott. If it is
an emergency and you cannot get in contact with David, you can
contact Drew at Arnett's (824-9022). He is familiar with the
system and may be able to correct the problem.
The fan switches on the thermostats should always be left in
the "on" position, not "auto". This will provide better humidity
control and air circulation in the house.