The Vikings inaugural first game at the Metrodome was on September 12, 1982. Over 64,000 seats in two tiers circle the entire field when the Metrodome is in football configuration. The Metrodome is one of the easiest stadium to be converted from baseball to football. The entire process takes around four hours. A section of 7,600 retractable seats make up the 23 foot high right field wall during a baseball game, but the seats are pulled out allowing the capacity to be increased during football games. The dome roof consists of over ten acres of Teflon-coated fiberglass. It is the only air-supported dome, and fans enter the park through revolving doors that prevent the release of the air that keeps the dome upright. The roof requires 250,000 cubic feet of air pressure per minute to remain inflated. The roof has snow melting ducts to prevent a collapse. However, in the fall of 1982, the dome collapsed, but was re-inflated. Since its opening in 1982, there have been several changes to the Metrodome. They include LED Boards, new color replay screens, a new Plaza outside the stadium, new rows of seats behind home plate for baseball, new Terrace Suite, re-construction of all concession stands, and new concourse televisions. After the 2003 season, the Astroturf field was removed and replaced with Fieldturf. Currently, the Vikings and the Twins are lobbying to get new stadiums built.