Exhibit 10.1

CHANGE IN CONTROL AGREEMENT

This Agreement, dated October 16, 2009, is entered into by and between CECO Environmental Corp. (the “Company”), and Dennis W. Blazer (“Executive”). For good and valuable consideration, the sufficiency of which is hereby acknowledged, the Company and the Executive agree as follows:

1. Definitions.

(a) “ Cause ” shall mean:

(i) negligence, fraud, dishonesty or misconduct by Executive in the performance of his duties;

(ii) intoxication with alcohol or drugs while on the premises of the Company or any of its subsidiaries or any customer or potential customer to the extent that in the reasonable judgment of management, Executive is abusive or his ability to perform his duties and responsibilities is impaired;

(iii) conviction of a felony or any misdemeanor involving dishonesty, theft, the failure to tell the truth, other unethical behavior, racial prejudice, drugs, alcohol, sexual misconduct or any other crime likely to result in public disparagement with respect to the Company or its subsidiaries;

(iv) intentional misappropriation of property belonging to the Company or any of its subsidiaries;

(v) illegal business practices in connection with the Company or any of its subsidiaries’ businesses which could have a material adverse effect on the Company or any of its subsidiaries’ business or financial position or reputation;

(vi) excessive absence of Executive from his employment during usual business hours for reasons other than vacation, disability or sickness after written notice thereof is delivered to Executive describing the nature of such excess absences and affording Executive one more opportunity to avoid excess absences;

(vii) failure of Executive to obey directions of the Board of Directors of CECO or the chief executive officer of the Company, provided that Executive has been given written notice of such directions; or

(viii) the breach by Executive of any confidentiality agreement between Executive and the Company.

(b) “ Change in Control ” shall mean the occurrence of any of the following: (i) any “person”, as the term is used in Section 3 of the Securities Exchange Act of 1934, as amended (“Exchange Act”) (other than a Company employee benefit plan) is or becomes the “beneficial owner” as defined in Rule 16a-1 under the Exchange Act, directly or indirectly, of securities of the Company representing

50% or more of the Company’s outstanding securities ordinarily having the right to vote in the election of directors; (ii) individuals who constitute the Board (the “Incumbent Board”), cease for any reason to constitute at least a majority thereof in any twelve month period, provided that any person becoming a director subsequent to the date hereof whose election was approved by a vote of at least three-quarters of the directors comprising the Incumbent Board shall be for purposes of this clause (ii) considered as though he or she were a member of the Incumbent Board; or (iii) a sale of substantially all of the Company’s assets, a liquidation or dissolution of the Company or a similar transaction.

(c) “ Date of Termination ” shall mean the date the Executive’s employment is terminated.

(d) “ Disability ” shall have the meaning in the Company’s long term disability plan.

(e) “ Good Reason ” shall mean: (i) the relocation of the location of Executive’s regular work place to a location more than 35 miles from its current location in Cincinnati, Ohio (excluding travel in the course of performing Executive’s duties), (ii) demotion of the Executive to a position with materially diminished authority, duties or responsibilities without the mutual agreement of the Company and the Executive, and (iii) the material reduction of Executive’s Base Salary below $260,000.

2. Termination. If during the period beginning on the date of the Change of Control and continuing one (1) year thereafter, the Company shall terminate the Executive’s employment other than for Cause, death or Disability, or the Executive shall terminate employment for Good Reason, then:

(a) The Company shall: (i) pay the Executive any base compensation due to the Executive through the Date of Termination, at the rate in effect immediately prior to the termination; (ii) continue to pay to the Executive the Executive’s base salary or compensation, at the rate in effect immediately prior to the Date of Termination, over a twel