AAON to Close Canadian Operations

TULSA, OK, May 18 (MARKET WIRE) --
AAON, Inc. (NASDAQ: AAON) today announced that it will close its Canadian
operations effective July 23, 2009.

Norman H. Asbjornson, President and CEO, stated that, "The closing will
have no significant affect on the Company's income statement or balance
sheet." He said, "The manufacture of Canada's custom equipment will be
relocated to the Company's Tulsa, Oklahoma, and Longview, Texas, plants."

AAON, Inc. is a manufacturer of air-conditioning and heating equipment
consisting of rooftop units, chillers, air-handling units and coils. Its
products serve the new construction and replacement markets. The Company
has successfully gained market share through its "semi-custom" product
lines, which offer the customer value, quality, function, serviceability
and efficiency.

Certain statements in this news release may be "forward-looking
statements" within the meaning of Section 27A of the Securities Act of
1933. Statements regarding future prospects and developments are based
upon current expectations and involve certain risks and uncertainties
that could cause actual results and developments to differ materially
from the forward-looking statements.

For Further Information:
Jerry R. Levine
Phone: (914) 244-0292
Fax: (914) 244-0295

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