10.3 Warrant Agreement

$1,200,000 December 28, 2006

WHEREAS, Can-Med Technology, Inc. d/b/a Green Diamond Oil Corp., an Ontario corporation ("Green Diamond") has prior to this date advanced sums to CECO Environmental Corp. (the "Company") as evidenced by a Second Amended and Restated Replacement Promissory Note dated December 29, 2005 (the "Prior Note"), which Prior Note shall be cancelled and replaced by this Third Amended and Restated Replacement Promissory Note (the "Note").

WHEREAS, Green Diamond has agreed to amend and restate the Prior Note and replace the Prior Note with this Note to extend the maturity date and increase the interest rate under the Prior Note.

FOR VALUE RECEIVED, the undersigned, CECO Environmental Corp. (the "Company"), a Delaware corporation, hereby promises to pay to the order of Green Diamond Oil Corp. or registered assigns ("Holder"), the principal sum of ONE MILLION TWO HUNDRED THOUSAND AND NO/100 ($1,200,000.00) on the Maturity Date, as defined in Section 1 below. This Note is subordinate to certain bank financing of the Company further described herein and to a series of promissory notes in the original principal amount of $5,000,000 originally issued on December 2, 1999 and subsequently amended and restated (the "December 1999 Notes"). The principal amount of the December 1999 Notes has been increased in connection with an amendment and restatement.

1. Maturity. This Note shall be due and payable upon the earlier to occur of the following events (the "Maturity Date"): (i) July 1, 2008 or (ii) the closing (any such closing referred to as the "Closing") of a Sale Transaction. For purposes of this Note, a Sale Transaction shall mean (i) a merger, consolidation, corporate reorganization, or sale of shares of stock of the Company as a result of which there is a change in control and/or the shareholders of the Company on the date hereof ("Current Shareholders") own 50% or less of the outstanding shares of the Company on a fully-diluted basis immediately after the transaction and, including as outstanding for purposes of such calculation, any warrants, options or other instruments convertible or exchangeable into equity securities of the Company issued to persons other than the Current Shareholders in connection with the transaction or (ii) the sale of (A) fifty percent or more of the assets of the Company or (B) any subsidiary, division or line of business of the Company for total consideration in excess of $5 million.

2. Interest. Interest shall accrue on the unpaid principal balance hereof and on any interest payment that is not made when due at the simple compounded rate of twelve percent (12%) per annum. Accrued interest shall be due and payable on March 31 and September 30 of each year and on the Maturity Date. It shall not be a default hereunder and interest will not accrue on any portion of such interest payments deferred pursuant to the Subordination Agreement ("Deferred Interest") so long as the Deferred Interest is paid at the time and in the manner allowed by the Subordination Agreement (as defined herein). In the Event of Default (as defined herein), interest shall accrue on all unpaid amounts due hereunder including without limitation, interest, at the rate of fifteen percent (15%) per annum. If a judgment is entered against the Company on this Note, the amount of the judgment so entered shall bear interest at the highest rate authorized by law as of the date of the entry of t he judgment.

3. Payments. Payments of both principal and interest shall be made at the Company's office in Toronto, Ontario, or such other place as the Holder hereof shall designate to the Company in writing, in lawful money of the United States of America. So long as no Event of Default has occurred in this Note, all payments hereunder shall first be applied to interest, then to principal. Upon the occurrence of an Event of Default in this Note, all payments hereunder shall first be applied to costs pursuant to Section 10.5, then to interest and the remainder to principal.

1. Registered Owner. Prior to due presentation for registration of transfer, the Company may treat the person in whose name this Note is registered as the owner and holder of such Note for the purpose of receiving payment of principal of, and interest on, this Note and for all other purposes.
2. Prepayment.

5.1 Optional Prepayment. The Company, at its option and without any premium, may prepay in whole or in part the principal amount of this Note at any time. The Company shall, at the time of any such prepayment, pay to the holder of this Note all interest accrued and unpaid to the Prepayment Date (defined below). Notwithstanding the foregoing, once a notice of the Closing of a Sale Transaction pursuant to Section 10.4 has been sent to the Holder, the Company may not prepay this Note prior to the Closing of a Sale Transaction, or until the Sale Transaction has been formally abandoned.

5.2 Notice of Prepayment. At least five (5) but not more than fifteen (15) days prior to the date fixed for any prepayment, written notice shall be given to the holder of this Note of the election of the Company to prepay all or a specified portion of the principal amount of the Note (the "Prepayment Notice."). The Prepayment Notice shall specify the date upon ("Prepayment Date") and the place at which, payment may be obtained and shall call upon the Holder to surrender this Note to the Company in the manner and at the place designated. On the Prepayment Date, the Holder shall surrender this Note to the Company in the manner and at the place designated in the Prepayment Notice, and thereupon prepayment shall be made to Holder and this Note shall be cancelled. In the event that less than all the principal amount of this Note is prepaid, upon surrender of this Note to the Company, the Company shall execute and deliver to Holder a new Note or Notes in princip al amount equal to the unpaid principal amount of this Note.

5.3 Cessation of Rights. From and after the Prepayment Date, unless there has been a default under the Prepayment Notice, all interest on the redeemed principal amount shall cease to accrue and all rights of Holder as a Holder of this Note shall cease with respect to the principal amount prepaid and, with respect to such amount, this Note thereafter shall not be deemed to be outstanding for any purpose whatsoever. By acceptance of this Note, Holder agrees to execute and deliver such documents as may be reasonably requested from time to time by the Company in order to implement the foregoing provisions of this Section.

3. Subordination. The indebtedness evidenced by this Note shall at all times be wholly subordinate and junior in right of payment to all obligations of the Company under or in connection with the Credit Agreement dated December 29, 2005 ("Superior Debt") among the Company, CECO Group Inc., CECO Filters, Inc., New Bush Co., Inc., The Kirk & Blum Manufacturing Company, kbd/Technic, Inc., CECOAire, Inc., CECO Abatement Systems, Inc. and Fifth Third Bank, upon the terms and conditions contained in the Subordination Agreement, dated as of December 29, 2005 (as amended, restated, supplemented or modified from time to time, the "Subordination Agreement") in favor of Fifth Third Bank (together with its successors and assigns, and the other holders, if any, of the Senior Obligations identified therein). This Note also is subordinate to the December 1999 Notes, and no payments of principal or interest shall be made under this Note, if an Event of Default (as defined in the December 1999 Notes) is existing under any of the December 1999 Notes.
4. Covenants of the Company. The Company covenants and agrees that it shall not, without the prior written approval of the Holder:

1. Allow, suffer or cause to exist any lien, claim, security interest or encumbrance on the Company's property or assets, other than with respect to the Superior Debt and purchase money indebtedness incurred in the ordinary course of business.
2. Enter into any arrangement or agreement involving the merger or consolidation of the Company.
3. Use the proceeds from this Note other than in the ordinary course of its business for general corporate purposes including lending monies to any of its subsidiaries. The Company also covenants and agrees that it shall operate its business in the ordinary course.

1. Events of Default.

1. if the Company fails to pay any amount payable, under this Note when due;
2. if the Company breaches any of its representations, warranties or covenants set forth in this Note;
3. the commencement of an involuntary case against the Company or its subsidiary or any of its subsidiaries under any applicable bankruptcy, insolvency or other similar law now or hereafter in effect, or the appointing of a receiver, liquidator, assignee, custodian, trustee or similar official of the Company or for any substantial part of the Company or one of its subsidiary's property, or ordering the winding-up or liquidation of the Company or one of its subsidiary's affairs;
4. if the Company or any of its subsidiaries shall commence a voluntary case under any applicable bankruptcy, insolvency or other similar law now or hereafter in effect, or shall consent to the entry of an order for relief in an involuntary case under any such law, or shall consent to the appointment of or taking possession by a receiver, liquidator, assignee, trustee, custodian or similar official of the Company or its subsidiary or for any substantial part of the Company or one of its subsidiary's property, or shall make any general assignment for the benefit of creditors, or shall take any corporate action in furtherance of any of the foregoing; or
5. if the Company's business shall fail, as determined in good faith by the Holder and evidenced by the Company's inability to pay its ongoing debts as such debts become due.

1. Investment Representations of the Holder. With respect to the purchase of this Note, the Holder hereby represents and warrants to the Company as follows:

10. Miscellaneous.

1. Invalidity of Any Provision. If any provision or part of any provision of this Note shall for any reason be held invalid, illegal or unenforceable in any respect, such invalidity, illegality or unenforceability shall not affect any other provisions of this Note and this Note shall be construed as if such invalid, illegal or unenforceable provisions or part hereof had never been contained herein, but only to the extent of its invalidity, illegality or unenforceability.

1. Notices. Any notice or other communication required or permitted hereunder shall be in writing and shall be deemed to have been duly given (i) on the date of delivery if delivered personally, (ii) one (1) business day after transmission by facsimile transmission with a written confirmation copy sent by first class mail, or (iii) five (5) days after mailing if mailed by first class mail, to the following addresses:

If to the Company: CECO Environmental Corp.

1. Successors and Assigns. The rights and obligations of the Company and the Holder shall be binding upon and benefit the successors, assigns, heirs, administrators and transferees of the parties.
2. Waivers. The Company and any endorsers, sureties, guarantors, and all others who are, or may become liable for the payment hereof severally: (a) waive presentment for payment, demand, notice of demand, notice of nonpayment or dishonor, protest and notice of protest of this Note, and all other notices in connection with the delivery, acceptance, performance, default, or enforcement of the payment of this Note, (b) consent to all extensions of time, renewals, postponements of time of payment of this Note or other modifications hereof from time to time prior to or after the maturity date hereof, whether by acceleration or in due course, without notice, consent or consideration to any of the foregoing, (c) agree to any substitution, exchange, addition, or release of any of the security for the indebtedness evidenced by this Note or the addition or release of any party or person primarily or secondarily liable hereon, (d) agree that Holder shall not be required first to institute any suit, or to exhaust its remedies against the Company or any other person or party to become liable hereunder or against the security in order to enforce the payment of this Note and (e) agree that, notwithstanding the occurrence of any of the foregoing (except by the express written release by Holder of any such person), the Company shall be and remain, directly and primarily liable for all sums due under this Note.
3. Time. Time is of the essence in this Note.
4. Captions. The captions of sections of this Note are for convenient reference only, and shall not affect the construction or interpretation of any of the terms and provisions set forth in this Note.
5. Number and Gender. Whenever used in this Note, the singular number shall include the plural, and the masculine shall include the feminine and the neuter, and vice versa.
6. Remedies. All remedies of the Holder shall be cumulative and concurrent and may be pursued singly, successively, or together at the sole discretion of the Holder and may be exercised as often as occasion therefor shall arise. No act of omission or commission of the Holder, including specifically any failure to exercise any right, remedy or recourse shall be effective unless it is set forth in a written document executed by the Holder and then only to the extent specifically recited therein. A waiver or release with reference to one event shall not be construed as continuing as a bar to or as a waiver or release of any subsequent right, remedy, or recourse as to any subsequent event.
7. No Waiver by Holder.  The acceptance by Holder of any payment under this Note which is less than the amount then due or the acceptance of any amount after the due date thereof, shall not be deemed a waiver of any right or remedy available to Holder nor nullify the prior exercise of any such right or remedy by Holder. None of the terms or provisions of this Note may be waived, altered, modified or amended except by a written document executed by Holder and then only to the extent specifically recited therein. No course of dealing or conduct shall be effective waive, alter, modify or amend any of the terms or provisions hereof. The failure or delay to exercise any right or remedy available to Holder shall not constitute a waiver of the right of the Holder to exercise the same or any other right or remedy available to Holder at that time or at any subsequent time.
8. Waiver of Trial by Jury. HOLDER AND BORROWER HEREBY KNOWINGLY, IRREVOCABLY, VOLUNTARILY AND INTENTIONALLY WAIVE ANY RIGHT EITHER MAY HAVE TO A TRIAL BY JURY IN RESPECT OF ANY ACTION, PROCEEDING OR COUNTERCLAIM BASED ON THIS NOTE, OR ARISING OUT OF, UNDER OR IN CONNECTION WITH THIS NOTE OR ANY OTHER DOCUMENT EXECUTED IN CONNECTION THEREWITH, OR ANY COURSE OF CONDUCT, COURSE OF DEALING, STATEMENTS (WHETHER VERBAL OR WRITTEN) OR ACTIONS OF ANY PARTY HERETO. THIS PROVISION IS A MATERIAL INDUCEMENT FOR HOLDER TO MAKE THE LOAN EVIDENCED BY THIS NOTE.

[signature page follows]

CECO ENVIRONMENTAL CORP.

By: /s/ Dennis W. Blazer

Dennis W. Blazer

Title: Vice President-Finance and Administration

and Chief Financial Officer

Can-Med Technology, Inc.

d/b/a Green Diamond Oil Corp.

By: /s/ Phillip DeZwirek

Its: /s/President

NEITHER THIS NOTE NOR ANY SECURITIES WHICH MAY BE ISSUED UPON THE EXERCISE OF THE WARRANTS HEREOF HAVE BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR REGISTERED OR OTHERWISE QUALIFIED UNDER ANY STATE SECURITIES LAW. NEITHER THIS NOTE NOR ANY SUCH SECURITIES MAY BE SOLD OR OFFERED FOR SALE IN THE ABSENCE OF AN EFFECTIVE REGISTRATION STATEMENT UNDER SAID ACT AND REGISTRATION OR OTHER QUALIFICATION UNDER ANY APPLICABLE STATE SECURITIES LAWS, OR AN OPINION OF COUNSEL SATISFACTORY TO THE COMPANY THAT SUCH REGISTRATION OR OTHER QUALIFICATION IS NOT REQUIRED.

FIFTH AMENDED AND RESTATED REPLACEMENT

$4,542,570 December 28, 2006

WHEREAS, Can-Med Technology, Inc. d/b/a Green Diamond Oil Corp., an Ontario corporation ("Green Diamond") has prior to this date advanced sums to CECO Environmental Corp. (the "Company") as evidenced by a Fourth Amended and Restated Replacement Promissory Note dated December 29, 2005 (the "Prior Note"), which Prior Note shall be cancelled and replaced by this Fifth Amended and Restated Replacement Promissory Note (the "Note").

WHEREAS, Green Diamond has agreed to amend and restate the Prior Note and replace the Prior Note with this Note to extend the maturity date under the Prior Note.

FOR VALUE RECEIVED, the undersigned, CECO Environmental Corp. (the "Company"), a Delaware corporation, hereby promises to pay to the order of Green Diamond Oil Corp. or registered assigns ("Holder"), the principal sum of FOUR MILLION FIVE HUNDRED FORTY-TWO THOUSAND FIVE HUNDRED AND SEVENTY DOLLARS ($4,542,570) on the Maturity Date, as defined in Section 1 below. This Note is part of a series of Notes of like tenor and effect to this Note in the aggregate original principal amount of $5,000,000, which aggregate principal amount has been increased to $6,441,315, that were originally issued in connection with a mezzanine financing by the Company (the "1999 Subordinated Notes").

1. Maturity. This Note shall be due and payable upon the earlier to occur of the following events (the "Maturity Date"): (i) July 1, 2008; (ii) six (6) months after repayment of the Superior Debt (as defined in Section 8 below); or (iii) the closing (any such closing referred to as the "Closing") of a Sale Transaction. For purposes of this Note, a Sale Transaction shall mean (i) a merger, consolidation, corporate reorganization, or sale of shares of stock of the Company as a result of which there is a change in control and/or the shareholders of the Company on the date hereof ("Current Shareholders") own 50% or less of the outstanding shares of the Company on a fully-diluted basis immediately after the transaction and, including as outstanding for purposes of such calculation, any warrants, options or other instruments convertible or exchangeable into equity securities of the Company issued to persons other than the Current Shareholders in connection with the transaction o r (ii) the sale of (A) fifty percent or more of the assets of the Company or (B) any subsidiary, division or line of business of the Company for total consideration in excess of $5 million.

2. Interest. Interest shall accrue on the unpaid principal balance hereof and on any interest payment that is not made when due at the simple compounded rate of twelve percent (12%) per annum. Accrued Interest shall be due and payable on June 30 and December 31 of each year. It shall not be a default hereunder and interest will not accrue on any portion of such interest payments deferred pursuant to the Subordination Agreement ("Deferred Interest") so long as the Deferred Interest is paid at the time and in the manner allowed by the Subordination Agreement. In the Event of Default (as defined herein), interest shall accrue on all unpaid amounts due hereunder, including without limitation, interest, at the rate of fifteen percent (15%) per annum. If a judgment is entered against the Company on this Note, the amount of the judgment so entered shall bear interest at the highest rate authorized by law as of the date of the entry of the judgment.

3. Payments. Payments of both principal and interest shall be made at the principal executive office of the Company, or such other place as the holder hereof shall designate to the Company in writing, in lawful money of the United States of America.

So long as no Event of Default has occurred in this Note, all payments hereunder shall first be applied to interest, then to principal. Upon the occurrence of an Event of Default in this Note, all payments hereunder shall first be applied to costs pursuant to Section 12.5, then to interest and the remainder to principal.

4. Registration, Transfer and Exchange of Notes. The Company will keep at its principal office a register in which it will provide for the registration of and transfer of this Note, at its own expense (excluding transfer taxes). If this Note is surrendered at said office or at the place of payment named in this Note for registration of transfer or exchange (accompanied in the case of registration of transfer or exchange by a written instrument of transfer in form satisfactory to the Company duly executed by or on behalf of the holder), the Company, at its expense, will deliver in exchange one or more new notes in denominations of $10,000 or larger multiples of $1,000, as requested by the holder for the aggregate unpaid principal amount. Any note or notes issued in a transfer or exchange shall carry the same rights to increase notes surrendered. The Holder agrees that prior to making any sale, transfer, pledge, assignment, hypothecation, or other disposition (each, a "Transfer ") of this Note, the Holder shall give written notice to the Company describing the manner in which any such proposed Transfer is to be made and providing such additional information and documentation regarding the Transfer as the Company reasonably requests. If the Company so requests, the Holder shall at his expense provide the Company with an opinion of counsel (which counsel must be reasonably satisfactory to the Company), in form and substance satisfactory to the Company, that the proposed Transfer complies with applicable federal and state securities laws. The Company shall have no obligation to Transfer this Note unless the Holder thereof has complied with the foregoing provisions, and any such attempted Transfer shall be null and void.

5. Registered Owner. Prior to due presentation for registration of transfer, the Company may treat the person in whose name this Note is registered as the owner and holder of such Note for the purpose of receiving payment of principal of, and interest on, such Note and for all other purposes.

6. Prepayment.

7. Subordination. The indebtedness evidenced by this Note shall at all times be wholly subordinate and junior in right of payment to all obligations of the Company under or in connection with the Credit Agreement dated December 29, 2005 ("Superior Debt") among the Company, CECO Group Inc., CECO Filters, Inc., New Bush Co., Inc., The Kirk & Blum Manufacturing Company, kbd/Technic, Inc., CECOAire, Inc., CECO Abatement Systems, Inc. and Fifth Third Bank, upon the terms and conditions contained in the Subordination Agreement, dated as of December 29, 2005 (as amended, restated, supplemented or modified from time to time, the "Subordination Agreement") in favor of Fifth Third Bank (together with its successors and assigns, and the other holders, if any, of the Senior Obligations identified therein).

8. Repayment of Notes. In the event the Company completes an equity financing or offering or a series of equity financing or offerings for a total consideration in excess of $10,000,000, then twenty-five percent (25%) of all such consideration in excess of $10,000,000 shall be used immediately, upon receipt by the Company, to pre-pay the 1999 Subordinated Notes, provided such prepayment shall be made proportionately among the 1999 Subordinated Notes until the 1999 Subordinated Notes are paid in full.

9. Covenants of the Company. The Company covenants and agrees that it shall not, without the prior written approval of the Holders of a majority of the aggregate principal amount outstanding of the 1999 Subordinated Notes ("Majority Holders"):

10. Events of Default.

11. Investment Representations of the Holder. With respect to the purchase of this Note, the Holder hereby represents and warrants to the Company as follows:

12. Miscellaneous.

[signature page follows]

CECO ENVIRONMENTAL CORP.

By: /s/Dennis W. Blazer

Dennis W. Blazer

Vice President -- Finance and Administration

and Chief Financial Officer

Can-Med Technology, Inc.

d/b/a Green Diamond Oil Corp.

By: /s/ Phillip DeZwirek

Its: /s/President

WARRANT AGREEMENT (the "Agreement") dated as of December 28, 2006 between CECO Environmental Corp., a Delaware corporation (the "Company"), and Can-Med Technology, Inc. d/b/a Green Diamond Oil Corp. (hereinafter referred to as a "Holder" or "Green Diamond").

WHEREAS, Green Diamond and the Company are parties to a Second Amended and Restated Replacement Promissory Note and a Fourth Amended and Restated Replacement Promissory Note, whereby the Company owes Green Diamond the sums set forth therein;

WHEREAS, Green Diamond agreed to extend the maturity date under the Notes from April 1, 2007 to July 1, 2008 pursuant to a Third Amended and Restated Replacement Promissory Note ("Replacement Note 1") and a Fifth Amended and Restated Replacement Promissory Note ("Replacement Note 2" and together with Replacement Note 1, the "Notes"); and

WHEREAS, as part of the consideration for Green Diamond's agreement to extend the maturity date under the Notes, the Company desires to grant to Green Diamond, and Green Diamond desires to accept from the Company, warrant certificates giving Green Diamond the right to purchase shares of the Company's Common Stock;

NOW, THEREFORE, in consideration of the premises, the agreements herein set forth and other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the parties hereto agree as follows:

1. Grant. Green Diamond is granted the right to purchase, from the Company, at any time from December 28, 2006, until 5:00 p.m., Eastern Standard Time, on December 28, 2016 (the "Expiration Date"), at which time the Warrants expire, up to an aggregate of 250,000 shares (subject to adjustment as provided in Section 8 hereof) of common stock, par value $.01 per share, of the Company ("Common Stock") at an initial exercise price (subject to adjustment as provided in Section 11 hereof) of $9.07 per share (the "Exercise Price").

2. Warrant Certificates. The warrant certificates (the "Warrant Certificates") delivered and to be delivered pursuant to this Agreement shall be in the form set forth in Exhibit A, attached hereto and made a part hereof, with such appropriate insertions, omissions, substitutions, and other variations as required or permitted by this Agreement.

3. Registration of Warrant. The Warrants shall be numbered and shall be registered on the books of the Company when issued.

4. Exercise of Warrant.

5. Issuance of Certificates. Upon the exercise of the Warrants, the issuance of certificates for shares of Common Stock shall be made forthwith (and in any event within five (5) business days thereafter) without charge to the Holder thereof including, without limitation, any tax which may be payable in respect of the issuance thereof, and such certificates shall (subject to the provisions of Sections 7 and 9 hereof) be issued in the name of, or in such names as may be directed by, the Holder thereof; provided, however, that the Company shall not be required to pay any tax which may be payable in respect of any transfer involved in the issuance and delivery of any such certificates in a name other than that of the Holder and the Company shall not be required to issue or deliver such certificates unless or until the person or persons requesting the issuance thereof shall have paid to the Company the amount of such tax or shall have established to the satisfaction of the Company that such tax has been paid.

The Warrant Certificates and the certificates representing the shares of Common Stock, or other securities, property or rights issued upon exercise of the Warrants shall be executed on behalf of the Company by the manual or facsimile signature of the then present Chief Executive Officer, President or any Vice President of the Company, attested to by the manual or facsimile signature of the then present Secretary or any Assistant Secretary of the Company. Warrant Certificates shall be dated the date of execution by the Company upon initial issuance, division, exchange, substitution or transfer.

6. Non-transferability of Warrants. The Warrants issued hereunder or any interest in such Warrants may not be sold, assigned, conveyed, gifted, pledged, hypothecated or otherwise transferred in any manner other than by will or the laws of descent and distribution. Notwithstanding any other Section of this Agreement, any such attempted sale, assignment, conveyance, gift, pledge, hypothecation or transfer shall be null and void and shall nullify such Warrants immediately.

7. Transfer of Warrant. The Warrants shall be transferable only as set forth in Section 6 above and only on the books of the Company maintained at its principal office, where its principal office may then be located, upon delivery thereof duly endorsed by the Holder or by its duly authorized attorney or representative accompanied by proper evidence of succession, assignment or authority to transfer. Upon any such permitted transfer, the Company shall execute and deliver new Warrants to the person entitled thereto.

8. Exercise Price and Number of Securities. Except as otherwise provided in Section 10 hereof, each of the Warrants are exercisable to purchase one share of Common Stock at an initial exercise price equal to the Exercise Price. The Exercise Price and the number of shares of Common Stock for which the Warrant may be exercised shall be the price and the number of shares of Common Stock which shall result from time to time from any and all adjustments in accordance with the provisions of Section 11 hereof.

9. Registration Rights.

Notwithstanding the provisions of this Section 9.2, the Company shall have the right at any time after it shall have given written notice pursuant to this Section 9.2 (irrespective of whether a written request for inclusion of any such securities shall have been made) to elect not to file any such proposed registration statement or to withdraw the same after the filing but prior to the effective date thereof.

10. Obligations of Holders. It shall be a condition precedent to the obligations of the Company to take any action pursuant to Section 9 hereof that each of the selling Holders shall:

11. Adjustments to Exercise Price and Number of Securities. The Exercise Price in effect at any time and the number and kind of securities purchasable upon the exercise of the Warrants or the securities underlying the Warrants shall be subject to adjustment from time to time upon the happening of certain events as follows:

(a) Upon the issuance or sale of the Warrants or the Warrant Shares;

12. Exchange and Replacement of Warrant Certificates. Each Warrant Certificate is exchangeable, without expense, upon the surrender thereof by the registered Holder at the principal executive office of the Company for a new Warrant Certificate of like tenor and date representing in the aggregate the Holder's right to purchase the same number of Warrant Shares in such denominations as shall be designated in such Warrant Certificate at the time of such surrender.

Upon receipt by the Company of evidence reasonably satisfactory to it of the loss, theft, destruction or mutilation of any Warrant Certificate, and, in case of loss, theft or destruction, of indemnity or security reasonably satisfactory to it and reimbursement to the Company of all reasonable expenses incidental thereto, and upon surrender and cancellation of the Warrant Certificate, if mutilated, the Company will make and deliver a new Warrant Certificate of like tenor, in lieu thereof.

13. Elimination of Fractional Interests. The Company shall not be required to issue certificates representing fractions of shares of Common Stock or other securities upon the exercise of the Warrants, nor shall it be required to issue scrip or pay cash in lieu of fractional interests, it being the intent of the parties that all fractional interests shall be eliminated by rounding any fraction up to the nearest whole number of shares of Common Stock or other securities, properties or rights.

14. Reservation and Listing of Securities. The Company shall at all times reserve and keep available out of its authorized shares of Common Stock, solely for the purpose of issuance upon the exercise of the Warrants, such number of shares of Common Stock or other securities, properties or rights as shall be issuable upon the exercise thereof or the exercise or conversion of any other exercisable or convertible securities underlying the Warrants. Every transfer agent and warrant agent (collectively "Transfer Agent") for the Common Stock and other securities of the Company issuable upon the exercise of the Warrants will be irrevocably authorized and directed at all times to reserve such number of authorized shares of Common Stock and other securities as shall be requisite for such purpose. The Company will keep a copy of this Agreement on file with every Transfer Agent for the Common Stock and other securities of the Company issuable upon the exercise of the Warrants. The C ompany will supply every such Transfer Agent with duly executed stock and other certificates, as appropriate, for such purpose. The Company covenants and agrees that, upon each exercise of the Warrants and payment of the Purchase Price, all shares of Common Stock and other securities issuable upon such exercise shall be duly and validly issued, fully paid, non-assessable and not subject to the preemptive rights of any stockholder. As long as the Warrants shall be outstanding, the Company shall use its best efforts to cause all shares of Common Stock and other securities issuable upon the exercise of the Warrants and the securities underlying the securities issuable upon exercise of the Warrants to be listed (subject to official notice of issuance) on all securities exchanges or securities associations on which the Common Stock issued to the public in connection herewith may then be listed and/or quoted.

15. Notices to Warrant Holders. Nothing contained in this Agreement shall be construed as conferring upon the Holder(s) of the Warrants the right to vote or to consent or to receive notice as a stockholder in respect of any meetings of stockholders for the election of directors or any other matter, or as having any rights whatsoever as a stockholder of the Company. If, however, at any time prior to the expiration of the Warrants and their exercise, any of the following events shall occur:

16. Notices. All notices, requests, consents and other communications hereunder shall be in writing and shall be deemed to have been duly made and sent when delivered, or mailed by registered or certified mail, return receipt requested:

(a) if to the registered Holder of the Warrants, to the address of such

Holder as shown on the books of the Company; or

17. Investment Representation. The Holder represents and warrants that the Warrants and any shares of Common Stock to be issued upon exercise of the Warrants are and will be acquired by the Holder solely for the Holder's own account for investment and not with a view to or for sale in connection with any distribution thereof. The Holder agrees that the Holder will not, directly or indirectly, offer, transfer, sell, pledge, convey, gift, assign, encumber, alienate, hypothecate or otherwise dispose of all or any shares of Common Stock underlying the Warrants (or solicit any offers to buy, purchase or otherwise acquire or take a pledge of all or any of the shares of Common Stock underlying the Warrants), except in compliance with this Agreement, the Act and the rules and regulations of the Commission thereunder, and in compliance with applicable state securities or "blue sky" laws.

18. Supplements; Amendments; Entire Agreement. This Agreement contains the entire understanding between the parties hereto with respect to the subject matter hereof and may not be modified or amended except by a writing duly signed by the party against whom enforcement of the modification or amendment is sought. The Company and the Holder(s) may from time to time supplement or amend this Agreement in order to cure any ambiguity, to correct or supplement any provision contained herein which may be defective or inconsistent with any provisions herein, or to make any other provisions in regard to matters or questions arising hereunder which the Company and the Holders may deem necessary or desirable and which the Company and the Holder deem shall not adversely affect the interests of the Holders of Warrant Certificates.

19. Successors. All of the covenants and provisions of this Agreement shall be binding upon and inure to the benefit of the Company, the Holder(s) and their respective successors and assigns hereunder.

20. Survival of Representations and Warranties. All statements in any schedule, exhibit or certificate or other instrument delivered by or on behalf of the parties hereto, or in connection with the transactions contemplated by this Agreement, shall be deemed to be representations and warranties hereunder. Notwithstanding any investigations made by or on behalf of the parties to this Agreement, all representations, warranties and agreements made by the parties to this Agreement or pursuant hereto shall survive.

21. Governing Law; Submission to Jurisdiction. This Agreement and each Warrant Certificate issued hereunder shall be deemed to be a contract made under the laws of the State of New York and for all purposes shall be construed in accordance with the laws of said State without giving effect to the rules of said State governing the conflicts of laws.

22. Severability. If any provision of this Agreement shall be held to be invalid or unenforceable, such invalidity or unenforceability shall not affect any other provision of this Agreement.

23. Captions. The caption headings of the Sections of this Agreement are for convenience of reference only and are not intended, nor should they be construed as, a part of this Agreement and shall be given no substantive effect.

24. Benefits of this Agreement. Nothing in this Agreement shall be construed to give to any person or corporation other than the Company and Green Diamond and any other registered Holder(s) of the Warrant Certificates or Warrant Shares any legal or equitable right, remedy or claim under this Agreement; and this Agreement shall be for the sole and exclusive benefit of the Company and Green Diamond and any other Holder(s) of the Warrant Certificates or Warrant Shares.

25. Counterparts. This Agreement may be executed in any number of counterparts and each of such counterparts shall for all purposes be deemed to be an original, and such counterparts shall together constitute but one and the same instrument.

IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be duly executed, as of the day and year first above written.

By:/s/ Dennis W. Blazer

Name:/s/ Dennis W. Blazer

Title:CFO

Can-Med Technology, Inc.

By: /s/ Phillip DeZwirek

Name: Phillip DeZwirek

Title:/s/ President

EXHIBIT A

WARRANT CERTIFICATE

THE WARRANTS REPRESENTED BY THIS CERTIFICATE AND THE OTHER SECURITIES ISSUABLE UPON EXERCISE THEREOF MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO (i) AN EFFECTIVE REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933, (ii) TO THE EXTENT APPLICABLE, RULE 144 UNDER SUCH ACT (OR ANY SIMILAR RULE UNDER SUCH ACT RELATING TO THE DISPOSITION OF SECURITIES), OR (iii) AN OPINION OF COUNSEL, IF SUCH OPINION SHALL BE REASONABLY SATISFACTORY TO COUNSEL FOR THE ISSUER, THAT AN EXEMPTION FROM REGISTRATION UNDER SUCH ACT IS AVAILABLE.

THE TRANSFER OR EXCHANGE OF THE WARRANTS OR OTHER SECURITIES REPRESENTED BY THIS CERTIFICATE IS RESTRICTED IN ACCORDANCE WITH THE WARRANT AGREEMENT REFERRED TO HEREIN.

EXERCISABLE ON OR BEFORE

5:00 P.M., EASTERN STANDARD TIME, DECEMBER 28, 2016

No.: 12-31-06-1

WARRANT CERTIFICATE

This Warrant Certificate certifies that Can-Med Technology, Inc. d/b/a Green Diamond Oil Corp., or registered assigns, is the registered holder of Warrants to purchase initially, at any time from December 28, 2006 until 5:00 p.m., Eastern Standard Time, on December 28, 2016 ("Expiration Date"), up to 250,000 shares, of fully-paid and non-assessable common stock, $.01 par value ("Common Stock") of CECO Environmental Corp., a Delaware corporation (the "Company"), at the initial exercise price, subject to adjustment in certain events, of $9.07 per share upon surrender of this Warrant Certificate and payment of the Exercise Price at the principal executive office of the Company, but subject to the conditions set forth herein. Payment of the Exercise Price shall be made by certified or official bank check in United States dollars payable to the order of the Company.

No Warrant may be exercised after 5:00 p.m., Eastern Standard Time, on the Expiration Date, at which time all Warrants evidenced hereby, unless exercised prior thereto, shall thereafter expire and shall be void.

The Warrants evidenced by this Warrant Certificate are part of a duly authorized issue of Warrants issued pursuant to the Warrant Agreement, which Warrant Agreement is hereby incorporated by reference in and made a part of this instrument and is hereby referred to for a description of the rights, limitation of rights, obligations, duties and immunities thereunder of the Company and the holders (the words "holders" or "holder" meaning the registered holders or registered holder) of the Warrants.

The Warrant Agreement provides that upon the occurrence of certain events the Exercise Price and the type and/or number of the Company's securities issuable thereupon may, subject to certain conditions, be adjusted. In such event, the Company will, at the request of the holder, issue a new Warrant Certificate evidencing the adjustment in the Exercise Price and the number and/or type of securities issuable upon the exercise of the Warrants; provided, however, that the failure of the Company to issue such new Warrant Certificates shall not in any way change, alter, or otherwise impair, the rights of the holder as set forth in the Warrant Agreement.

Upon due presentment for registration of transfer of this Warrant Certificate at the principal executive office of the Company, a new Warrant Certificate or Warrant Certificates of like tenor and evidencing in the aggregate a like number of Warrants shall be issued to the transferee(s) in exchange for this Warrant Certificate, subject to the limitations provided herein and in the Warrant Agreement, without any charge except for any tax or other governmental charge imposed in connection with such transfer.

Upon the exercise of less than all of the Warrants evidenced by this Certificate, the Company shall forthwith issue to the holder hereof a new Warrant Certificate representing such numbered of unexercised Warrants.

The Company may deem and treat the registered holder(s) hereof as the absolute owner(s) of this Warrant Certificate (notwithstanding any notation of ownership or other writing hereon made by anyone), for the purpose of any exercise hereof, and of any distribution to the holder(s) hereof, and for all other purposes, and the Company shall not be affected by any notice to the contrary.

All terms used in this Warrant Certificate which are defined in the Warrant Agreement shall have the meanings assigned to them in the Warrant Agreement.

This Warrant Certificate does not entitle any Warrant holder to any of the rights of a shareholder of the Company.

IN WITNESS WHEREOF, the Company has caused this Warrant Certificate to be duly executed under its corporate seal.

Dated as of December 28, 2006.

By:/s/ Dennis W. Blazer

Title:/s/ CFO

ELECTION TO PURCHASE PURSUANT TO SECTION 4.1 OF THE

The undersigned hereby irrevocably elects to exercise the right, represented by a Warrant Certificate No. 12-31-06-1, to purchase shares of Common Stock (as defined in the Warrant Agreement described below) and herewith tenders in payment for such securities a certified or official bank check payable in United States dollars to the order of CECO Environmental Corp., a Delaware corporation (the "Company") in the amount of $____________, all in accordance with the terms of Section 4.1 of the Warrant Agreement dated as of December 28, 2006 between the Company and Can-Med Technology, Inc. d/b/a Green Diamond Oil Corp. The undersigned requests that a certificate for such securities be registered in the name of the undersigned, and if said number of shares of Common Stock shall not be all the shares of Common Stock purchasable hereunder, that a new Warrant Certificate for the balance of the shares of Common Stock purchasable under the within Warrant Certificate be registered in the name of the undersigned warrant holder or his assignee as below indicated and delivered to the address stated below.

Dated:

Signature: _______________________________________

(Signature must conform in all respects to name of holder as specified on the face of the Warrant Certificate.)

Address:_________________________________________

________________________________________________

________________________________________________

________________________________________________

Signature Guaranteed: ____________________________________________________________

(Signature must be guaranteed by a bank, savings and loan association, stockbroker, or credit union with membership in an approved signature guaranty Medallion Program pursuant to Securities Exchange Act Rule 17Ad-15.)