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                                                                       EXHIBIT 5


                              BAKER & BOTTS, L.L.P.
                                2001 Ross Avenue
                               Dallas, Texas 75201


                                                              September 13, 1999


Lennox International Inc.
2140 Lake Park Blvd.
Richardson, Texas 75080

Ladies and Gentlemen:

                  As set forth in the Registration Statement on Form S-8 (the
"Registration Statement") to be filed by Lennox International Inc., a Delaware
corporation (the "Company"), with the Securities and Exchange Commission under
the Securities Act of 1933, as amended (the "Securities Act"), relating to
40,000 shares (the "Shares") of the common stock, par value $0.01 per share
("Common Stock"), of the Company, that may be issued pursuant to the Lennox
International Inc. Nonemployee Directors' Compensation and Deferral Plan (the
"Plan"), certain legal matters in connection with the Shares are being passed
upon for the Company by us. At your request, this opinion is being furnished to
you for filing as Exhibit 5 to the Registration Statement.

                  In our capacity as counsel to the Company in the connection
referenced above, we have examined the Company's Restated Certificate of
Incorporation and Amended and Restated Bylaws, each as amended to date, and the
Plan, and have examined the originals, or copies certified or otherwise
identified, of corporate records of the Company, including minute books of the
Company as furnished to us by the Company, certificates of public officials and
of representatives of the Company, statutes and other instruments and documents
as a basis for the opinions hereinafter expressed.

                  We have assumed that all signatures on all documents examined
by us are genuine, that all documents submitted to us as originals are
authentic, that all documents submitted to us as copies are true and correct
copies of the originals thereof and that all information submitted to us was
accurate and complete. In addition, we have assumed for purposes of paragraph 2
below that the consideration received by the Company for the Shares will not be
less than the par value of the Shares.

                  Based upon our examination as aforesaid, and subject to the
assumptions, qualifications, limitations and exceptions herein set forth, we are
of the opinion that:



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Lennox International Inc.              -2-                    September 13, 1999




                  1. The Company is a corporation duly incorporated and validly
         existing in good standing under the laws of the State of Delaware.

                  2. When issued and sold from time to time in accordance with
         the provisions of the Plan for consideration calculated pursuant to the
         terms and provisions of the Plan, the Shares will be duly authorized by
         all necessary corporate action on the part of the Company, validly
         issued, fully paid and nonassessable.

                  The opinions set forth above are limited to the General
Corporation Law of the State of Delaware, and no opinion is expressed herein as
to matters governed by the law of any other jurisdiction.

                  We hereby consent to the filing of this opinion as an exhibit
to the Registration Statement.

                                               Very truly yours,

                                               /s/ BAKER & BOTTS, L.L.P.