# EDGAR Filing Document

**Accession Number:** 0001216231
**File Stem:** 0001193125-26-255971
**Filing Date:** 2026-6
**Character Count:** 8205
**Document Hash:** fde26ae3b19768ae743f0e4a37ea7832
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193125-26-255971.hdr.sgml**: 20260603

**ACCESSION NUMBER**: 0001193125-26-255971

**CONFORMED SUBMISSION TYPE**: 4

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20260601

**FILED AS OF DATE**: 20260603

**DATE AS OF CHANGE**: 20260603

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** RICHEY VICTOR L JR
- **CENTRAL INDEX KEY:** 0001216231

**ORGANIZATION NAME:**

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 000-07099
- **FILM NUMBER:** 261062659

**MAIL ADDRESS:**
- **STREET 1:** 28601 CLEMENS ROAD
- **CITY:** WESTLAKE
- **STATE:** OH
- **ZIP:** 44145
**ISSUER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** CECO ENVIRONMENTAL CORP
- **CENTRAL INDEX KEY:** 0000003197
- **STANDARD INDUSTRIAL CLASSIFICATION:** INDUSTRIAL & COMMERCIAL FANS & BLOWERS & AIR PURIFYING EQUIP [3564]
- **ORGANIZATION NAME:** 06 Technology
- **EIN:** 132566064
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**BUSINESS ADDRESS:**
- **STREET 1:** 5080 SPECTRUM DRIVE
- **STREET 2:** SUITE 800E
- **CITY:** ADDISON
- **STATE:** TX
- **ZIP:** 75001
- **BUSINESS PHONE:** (513) 458-2600

**MAIL ADDRESS:**
- **STREET 1:** 5080 SPECTRUM DRIVE
- **STREET 2:** SUITE 800E
- **CITY:** ADDISON
- **STATE:** TX
- **ZIP:** 75001

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** API ENTERPRISES INC
- **DATE OF NAME CHANGE:** 19920703

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** ALARM PRODUCTS INTERNATIONAL INC
- **DATE OF NAME CHANGE:** 19851210

### UNITED STATES SECURITIES AND EXCHANGE COMMISSION
**Washington, D.C. 20549**

## FORM 4

### STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

[ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

[ ] Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>RICHEY VICTOR L JR<br><sub>(Last) (First) (Middle)</sub><br>5080 SPECTRUM DRIVE<br>SUITE 800E<br><sub>(Street)</sub><br>ADDISON, TX 75001<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2026-06-01 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director [ ] 10% Owner<br>[ ] Officer (give title below) [ ] Other (specify below)<br>_ _ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>CECO ENVIRONMENTAL CORP [ CECO ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[X] Form filed by One Reporting Person<br>[ ] Form filed by More than One Reporting Person |

---

## Table I - Non-Derivative Securities

---

|  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | 3. Transaction Code (V) | 3. Transaction Code (V) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | Code | V | Amount | (A) or (D) | Price | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
| Common Stock | 2026-06-01 |  | A |  | 6378 | A | <sup>(1)(2)(3)</sup> | 6378 | D |  |

---

## Table II - Derivative Securities

---

|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | 4. Transaction Code (V) | 4. Transaction Code (V) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 6. Date Exercisable and Expiration Date | 6. Date Exercisable and Expiration Date | 7. Title and Amount of Underlying Securities | 7. Title and Amount of Underlying Securities | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | Code | V | (A) | (D) | Date Exercisable | Expiration Date | Title | Amount or Number of Shares | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
| Restricted Stock Units | <sup>(4)</sup> | 2026-06-01 |  | A |  | 2215 |  | <sup>(5)</sup> | <sup>(5)</sup> | Common Stock | 2215 | $0 | 2215 | D |  |

---

### Footnotes:

(1) On June 1, 2026 (the "Closing Date"), pursuant to an Agreement and Plan of Merger, dated as of February 23, 2026 (the "Merger Agreement"), by and among CECO Environmental Corp. (the "Issuer"), Thermon Group Holdings, Inc. ("Thermon"), Longhorn Merger Sub, Inc. ("Merger Sub, Inc.") and Longhorn Merger Sub LLC ("Merger Sub LLC"), (i) Merger Sub, Inc. merged with and into Thermon, with Thermon continuing as a wholly-owned subsidiary of the Issuer and the surviving corporation of the merger (the "First Merger") and (ii) Thermon, as the surviving corporation of the First Merger, merged with and into Merger Sub LLC, with Merger Sub LLC being the surviving entity of the merger.

(2) (Continued from Footnote 1) Pursuant to the Merger Agreement, at the effective time of the First Merger (the "Effective Time"), each share of Thermon's common stock issued and outstanding immediately prior to the Effective Time was converted into the right to receive, at the election of the holder and subject to the proration mechanisms set forth in the Merger Agreement, one of the following forms of merger consideration: (A) 0.6840 shares of the Issuer's common stock plus $10.00 in cash without interest (the "Mixed Election Consideration"), (B) $63.89 in cash, (C) 0.8110 shares of the Issuer's common stock (the "Stock Election Consideration"), or (D) for any shares of Thermon's common stock for which no election was made, the Mixed Election Consideration.

(3) (Continued from Footnote 2) The Reporting Person elected to receive the Stock Election Consideration in exchange for his shares of Thermon common stock. As a result, the Reporting Person received 6,378 shares of the Issuer's common stock in exchange for shares of Thermon common stock held by the Reporting Person immediately prior to the Effective Time.

(4) Represents restricted stock units granted under the CECO Environmental Corp. Deferred Compensation Plan for Non-Employee Directors. Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock and will vest on May 15, 2027.

(5) Conversion of restricted stock units to the Issuer's common stock and distribution of such stock under the Deferred Compensation Plan is deferred until termination of service as a director.

**Signature:** /s/ Kiril Kovachev as Attorney-in-Fact for Victor L. Richey Jr.  
**Date:** 2026-06-03

### Remarks:

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.

**Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.**