Thermon Group Holdings, Inc.

DEFM14A 1 tm2612301-1_defm14a.htm DEFM14A TABLE OF CONTENTS UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 ​ SCHEDULE 14A PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES EXCHANGE ACT OF 1934 (AMENDMENT NO. ) ​ Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Information Statement ​ ☐ Confidential for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ​ ☒ Definitive Proxy Statement ​ ☐ Definitive Additional Materials ​ ☐ Soliciting Material under §240.14a-12 ​ Thermon Group Holdings, Inc. ​ (Name of Registrant as Specified in its Charter) ​ (Name of Person(s) Filing Proxy Statement, if other than the Registrant) Payment of Filing Fee (Check all boxes that apply): ☒ No fee required ​ ☐ Fee paid previously with preliminary materials ​ ☐ Fee computed on table in exhibit required by Item 25(b) per Exchange Act Rules 14a-6(i)(1) and 0-11 ​ TABLE OF CONTENTS Filed Pursuant to Rule 424b3 ​ Registration No. 333-294924 ​ ​ ​ ​ ​ JOINT PROXY STATEMENT/PROSPECTUS MERGER PROPOSED — YOUR VOTE IS VERY IMPORTANT On behalf of the boards of directors of CECO Environmental Corp. (“CECO” or “Parent”) and Thermon Group Holdings, Inc. (“Thermon” or the “Company”), we are pleased to enclose the accompanying joint proxy statement/prospectus relating to the proposed combination of CECO and Thermon. We are requesting that you take certain actions as a CECO or Thermon stockholder. On February 23, 2026, CECO, Longhorn Merger Sub, Inc., a Delaware corporation and a direct wholly owned subsidiary of CECO (“Merger Sub Inc.”), Longhorn Merger Sub LLC, a Delaware limited liability company and a direct wholly owned subsidiary of CECO (“Merger Sub LLC”), and Thermon entered into an Agreement and Plan of Merger (as may be amended from time to time, the “merger agreement”), pursuant to which CECO will acquire Thermon through a series of mergers. In the first merger, Merger Sub Inc. will merge with and into Thermon, with Thermon surviving as a wholly owned subsidiary of CECO (the “first merger” and the surviving entity, the “surviving corporation”). Immediately following the first merger, the surviving corporation will merge with and into Merger Sub LLC, with Merger Sub LLC continuing as the surviving entity (the “second merger” and, together with the first merger, the “mergers,” and the surviving entity, the “surviving company”). The first merger will become effective at such time as the parties shall agree and shall specify in the certificate of merger filed with the Secretary of State of the State of Delaware (the “effective time”). The second merger will become effective one minute after the effective time, or at such later time as the parties shall agree and shall specify in the certificate of merger for the second merger (the “second merger effective time”). In the first merger, each share of common stock, par value $0.001 per share, of Thermon (“Thermon common stock”) (other than certain excluded shares and dissenting shares) will be converted into the right to receive, at the election of the holder, one of the following forms of merger consideration, subject, in the case of any cash election or stock election, to proration as described in the merger agreement: • Mixed Election: 0.6840 shares of common stock, par value $0.01 per share, of CECO (“CECO common stock”) and $10.00 in cash, without interest (the “mixed consideration”). Shares for which no election is made will be treated as mixed election shares. ​ • Cash Election: $63.89 in cash per share, without interest (the “cash consideration”). ​ • Stock Election: 0.8110 shares of CECO common stock per share (the “stock consideration”). ​ Importantly, although Thermon stockholders may elect among these three options, the aggregate amount of cash and stock to be paid by CECO in the mergers is fixed. Based on the number of shares of Thermon common stock expected to be outstanding at closing, the total cash payable by CECO is capped at approximately $334 million and the total CECO shares issuable is capped at approximately 22.9 million shares. Cash and stock needed to pay the mixed consideration (the default for stockholders who make no election) are funded first from each pool, and only the remainder is available to satisfy cash elections and stock elections. Accordingly, all elections for all-cash or all-stock consideration are subject to mandatory proration to the extent cumulative elections exceed the amounts available, and stockholders who made those elections may receive a prorated amount of their chosen consideration and the balance in the alternative form. The mixed consideration is not subject to proration. Following the closing of the mergers, it is anticipated that persons who were stockholders of CECO or Thermon immediately prior to the mergers will own approximately 62.5% and 37.5% of the combined company on a fully diluted basis, respectively. The actual ownership percentages will depend on the number of shares of CECO common stock and Thermon common stock issued and outstanding immediately prior to the effective time. CECO and Thermon will each hold meetings of their respective stockholders in connection with the mergers (as may be adjourned or postponed from time to time, respectively, the “CECO annual meeting” and the “Thermon special meeting”). TABLE OF CONTENTS At the CECO annual meeting, CECO stockholders will be asked to consider and vote various proposals described herein, including on a proposal to approve the issuance of shares of CECO common stock in connection with the first merger and other shares of CECO common stock to be issued in the mergers or reserved for issuance in connection with the mergers (the “CECO stock issuance proposal”). The CECO board of directors unanimously recommends that CECO stockholders vote “FOR” the CECO stock issuance proposal and the other proposals described herein. At the Thermon special meeting, Thermon stockholders will be asked to consider and vote on proposals to (1) adopt the merger agreement (the “Thermon merger proposal”) and (2) approve, on a non-binding advisory basis, the compensation that may be paid or become payable to Thermon’s named executive officers in connection with the mergers (the “Thermon compensation proposal”). The Thermon board of directors unanimously recommends that Thermon stockholders vote “FOR” each of the proposals to be considered at the Thermon special meeting. Concurrently with the execution of the merger agreement, Jason DeZwirek, Chairman of the CECO board, and Todd Gleason, Chief Executive Officer and a director of CECO, entered into voting agreements with CECO and Thermon, pursuant to which, subject to the terms and conditions therein, each has agreed to vote all of his respective shares of CECO common stock in favor of the CECO stock issuance proposal. As of April 17, 2026, Messrs. DeZwirek and Gleason collectively owned approximately 5,519,870 shares of CECO common stock (including shares beneficially owned), representing approximately 15.4% of the outstanding shares of CECO common stock. Copies of the voting agreements are attached as Annex G to this joint proxy statement/prospectus. For additional information, see the section titled “ Voting Agreements ” beginning on page 37 of this joint proxy statement/prospectus. CECO common stock is traded on the Nasdaq Stock Market LLC (“Nasdaq”) under the symbol “CECO,” and Thermon common stock is traded on the New York Stock Exchange (the “NYSE”) under the symbol “THR.” The market prices of both CECO common stock and Thermon common stock will fluctuate before the mergers, and you should obtain current stock price quotations for CECO common stock and Thermon common stock. Your vote is very important. We cannot complete the mergers unless the CECO stockholders vote to approve the CECO stock issuance proposal and the Thermon stockholders vote to adopt the merger agreement. This document