April 30, 2019 Matthew Eckl Chief Financial Officer CECO Environmental Corp. 14651 North Dallas Parkway, Suite 500 Dallas, TX 75254 Re: CECO Environmental Corp. Registration Statement on Form S-3 April 24, 2019 File No. 333-231001 Dear Mr. Eckl: This is to advise you that we have not reviewed and will not review your registration statement. Please refer to Rules 460 and 461 regarding requests for acceleration. We remind you that the company and its management are responsible for the accuracy and adequacy of their disclosures, notwithstanding any review, comments, action, or absence of action by the staff. Please contact Edward M. Kelly, Senior Counsel, at (202) 551-3728 with any questions. Sincerely, Division of Corporation Finance Office of Manufacturing and Construction