POWER OF ATTORNEY

  KNOW ALL MEN BY THESE PRESENTS, that the undersigned hereby constitutes and
appoints Mathew Eckl, and Paul Gohr, and each of them, as the true and lawful
attorney or attorneys-in- fact, with full power of substitution and revocation,
for the undersigned and in the name, place and stead of the undersigned, in any
and all capacities, to execute, on behalf of the undersigned, (1) any and all
notices pursuant to Rule l44 under the Securities Act of 1933 with respect to
sales of shares of common stock, par value $0.01 per share, or other securities,
of CECO Environmental Corp., including, without limitation, all notices of
proposed sale on Form 144, and (2) any and all statements or reports under
Section 16 of the Securities Exchange Act of 1934 with respect to the beneficial
ownership of common stock, par value $0.01 per share, or other securities, of
CECO Environmental Corp., including, without limitation, all initial statements
of beneficial ownership on Form 3, all statements of changes in beneficial
ownership on Form 4, all annual statements of beneficial ownership on Form 5 and
all successor or similar forms, to be filed with the Securities and Exchange
Commission, to execute any and all amendments or supplements to any such
notices, statements or reports, and to file the same, with all exhibits thereto,
and other documents in connection therewith, with the Securities and Exchange
Commission, granting to said attorney or attorneys-in-fact, and each of them,
full power and authority to do so and perform each and every act and thing
requisite and necessary to be done in and about the premises (including, without
limitation, completing, executing, delivering and filing a Form ID to apply for
electronic filing codes), as fully and to all intents and purposes as the
undersigned might or could do in person, and hereby ratifying and confirming all
that said attorney or attorneys-in-fact, or any of them, or their substitute or
substitutes, may lawfully do or cause to be done by virtue hereof. The
undersigned acknowledges that the foregoing attorneys-in-fact, and each of them,
in serving in such capacity at the request of the undersigned, are not assuming
any of the responsibilities of the undersigned to comply with Section 16 of the
Securities Exchange Act of 1934 or any other legal requirement. This Power of
Attorney shall remain in effect until revoked in writing by the undersigned.



                                     /s/ Robert E. Knowling, Jr.
                                     -----------------------------
                                     Name: Robert E. Knowling Jr.

Date: July 11, 2022