SecProbe.io

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549-7010

       DIVISION OF
CORPORATION FINANCE

Mail Stop 7010
October 25, 2007
 Via U.S. mail and facsimile

 Mr. Dennis W. Blazer V.P. - Finance and Administrati on and Chief Financial Officer
CECO Environmental Corp. 3120 Forrer Street
Cincinnati, OH  45209

 RE: Form 10-K for the fiscal  year ended D ecember 31, 2006
Form 10-Q for the quarte r ended June 30, 2007
File No. 0-07099

Dear Mr. Blazer:    We have reviewed your filings and have the following comments.  If you disagree with a comment, we will consider your explanation as to why our comment is inapplicable or a revision is unnecessary.  Pl ease be as detailed as necessary in your
explanation.  In some of our comments, we may ask you to provide us with information so we may better understand your disclosure.  After reviewing this information, we may
or may not raise additional comments.   Please understand that the purpose of our re view process is to assist you in your
compliance with the applicable disclosure  requirements and to  enhance the overall
disclosure in your filing.  We look forward to  working with you in these respects.  We
welcome any questions you may have about our comments or on any other aspect of our review.  Feel free to call us at the telephone numbers listed at the end of this letter.

FORM 10-K FOR THE YEAR ENDED DECEMBER 31, 2006

 General

1. Where a comment below requests additional disclosures or other revisions to be
made, please show us in your response wh at the revisions will look like.  These
revisions should be included in your future  filings, including your interim filings.

Mr. Dennis W. Blazer
CECO Environmental Corp.
October 25, 2007 Page 2    Management’s Discussion and Analysis of Fi nancial Condition and Results of Operations

Results of Operations, page 33

2. Please quantify the impact of each factor when multiple factors contribute to material fluctuations.  For example,  in your discussion of $54 million and $4.5
million increases to consolidated sales and selling and administrative expenses, respectively, you appear to only quantif y the portion of th e increase (20-25%)
attributable to the additional of H.M. Wh ite, Inc.  Furthermore, you state that the
decrease in the gross profit percentage from 2005 to 2006 was due to changes in
product mix and an underperforming large pr oduct but do not quantify the impact of
either so that a reader is able to the determine the extent to which each factor
impacted your results.  Refer to Items 303( a)(3)(i) and (iii) of  Regulation S-K and
Financial Reporting Codification 501.04.

Consolidated Financial Statements

Consolidated Statements of Operations, page F-5
 3. We note your disclosure on page 35 that ot her income (expense) for the year ended
December 31, 2005 included a non-cash charge of $173,000 related to the
impairment of fixed assets which had been  retained from the discontinued operation
of U.S. Facilities Management.  Please revi se your filing to present the loss within
operating expenses or explain why your curr ent treatment is appropriate.  Refer to
paragraph 45 of SFAS 144.
 Consolidated Statements of Shareholders’ Equity, page F-6

 4. Please revise to disclose the accumulated balances for each classification within
accumulated other comprehensive income.  You may disclose this information on
the face of the balance sheet, in the statemen t of shareholders’ equity or in the notes
the financial statements.  Refer to paragraph 26 of SFAS 130.

Note 9 – Debt, page F-17

5. It appears from your disclosures on page F- 18 that you modified your Credit Facility
with Fifth Third Bank in June 2006 and ag ain in February 2007.  We also notice
your disclosures on page F-19 indicating that your subordinated debt agreement with Green Diamond has been modified multiple  times, most recently in December 2006
and March 2007.  Please tell us in detail how you considered the provisions of EITF
96-19 (including paragraph 1f) in determ ining the accounting treatment for each
separate modification.  Please revise your filing to describe how you accounted for any fees paid or received in connect ion with modifications, if applicable.

Mr. Dennis W. Blazer
CECO Environmental Corp.
October 25, 2007 Page 3     Note 11 – Shareholders’ Equity, page F-19

 6. So that we may better understand your acc ounting treatment, please tell us how you
accounted for the issuance of the detachab le stock warrants issued in December
2001, including the financial statement lin e items to which you recorded amounts
related to the warrants, methods used fo r calculating fair value of the warrants upon
issuance, how you determined the market value adjustments associated with your
warrants, and the circumstances under which you recorded such adjustments.  Please also describe the authoritative literature you relied upon to support your accounting
treatment.
 Note 12 – Pension and Employee Benefit Plans, page F-24

 7. Please revise future filings to clarify, if  true, that the funded status for your post-
retirement health care plan is calculated based on the accumulated
 post-retirement
benefit obligation instead of the projected  benefit obligation as could be inferred
from your current disclosure.  If your f unded status is calculated based upon the
projected benefit obligation, please tell us how you determined that your accounting
is consistent with paragraph 4a of SFAS 158.

8. Please revise to provide the disclosures required by paragraphs  7(a)-(c) of SFAS
158.

9. It appears from your disclosures on page  F-24 that you determined the required
adjustments to the ending balance of accumulated other comprehensive income due to the adoption of SFAS 158 was $208,000 fo r your defined benefit plan and
$18,000 for your post-retirement health plan.  However, it is appears that this
adjustment may not be properly classified in  your statement of shareholders’ equity.
The amount of the adjustment should be  reflected within accumulated other
comprehensive income as of December 31, 2006 but should not appear in the amount of total comprehensive income for the year ended December 31, 2006.  Please see paragraph A6 and A7 of SFAS  158 and revise your filing accordingly.

FORM 10-Q FOR THE PERIOD ENDED JUNE 30, 2007

Condensed Consolidated Statements of Operations, page 3
 10. Please revise future filings beginning with your next Form 10-Q to report a total for
comprehensive income in your condensed fi nancial statements of interim periods.
See paragraph 27 of SFAS 130.

Mr. Dennis W. Blazer
CECO Environmental Corp. October 25, 2007 Page 4
*    *    *    *
      Please respond to these comments with in 10 business days, or tell us when you
will provide us with a response.  Please provi de us with a response letter that keys your
responses to our comments and provides a ny requested information.  Detailed letters
greatly facilitate our review.  Pleas e furnish your response on EDGAR as a
correspondence file.  Please understand that we may have additional comments after reviewing your responses to our comments.
We urge all persons who are responsible for the accuracy and adequacy of the
disclosure in the filings reviewed by the staff to be certain that they have provided all information investors require for an info rmed decision.  Since the company and its
management are in possession of all facts re lating to a company’s disclosure, they are
responsible for the accuracy and adequacy of the disclosures they have made.

 In connection with responding to our comments, please provide, in writing, a statement from the company acknowledging that:
• the company is responsible for the adequacy and accuracy of the disclosure in
their filings;
• staff comments or changes to disclosure  in response to staff comments do not
foreclose the Commission from taking any action with respect to the filing; and
• the company may not assert staff comme nts as a defense in any proceeding
initiated by the Commission or any pers on under the federal s ecurities laws of
the United States.

  In addition, please be advi sed that the Division of En forcement has access to all
information you provide to the staff of the Divi sion of Corporation Fi nance in our review
of your filing or in response to our comments on your filing.

If you have any questions regarding these comments, please direct them to Lisa
Haynes, Staff Accountant, at (202) 551-3424 or, in her absen ce, to the undersigned at
(202) 551-3769.          S i n c e r e l y ,              R u f u s  D e c k e r          A c c o u n t i n g  B r a n c h  C h i e f