Its green potential

Here is a somewhat different way to look at what might be done with the Igloo if it is preserved:

The Mellon Arena has a "secret" potential for lowering air conditioning and ventilating loads, which could save a lot of money. The "secret" lies in a simple timing procedure for opening and closing the roof during the summer.

Here it is:

After a nighttime event at the arena is over, and the people have left, the roof should be kept closed. At the coolest time of the next day (usually between 5 a.m. and 7 a.m.), the roof should be completely opened.

The cooler (and heavier) outside air would dump into the arena and flush out the warmer (lighter) air that was left over from the previous nighttime event. After the flushing, the roof should be quickly closed again, so that the arena contains only the cool, fresh morning air.

At the start of the next event, people would begin to fill up the seats, adding their heat to the arena. Ordinarily the air conditioning and ventilating systems would then start up full blast to keep down the temperature of the air in the dome. However, if the timing scheme were used, these systems would not have to work hard, because the arena would be initially filled with cool, fresh morning air.

This timing scheme should be considered among the many pros and cons of preserving the Igloo.

JOHN C. SCHMERTZ
Wilkinsburg
The writer is a retired mechanical engineer.