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                                                                  EXHIBIT 10.19

                            [NATIONSBANK LETTERHEAD]

May 12,1997

Mr. Anthony R. Maresca
Senior Vice President
ACR Group, Inc.
3200 Wilcrest Drive, Suite 440
Houston, Texas 77042

Re:      NationsBank of Texas, N.A. ("Lender") re: Credit facility for ACR
         Group, and Subsidiaries

Dear Tony:

We are pleased to advise you that we have obtained credit approval for a credit
facilities for each of ACR Group, Inc., ACR Supply, Inc., Heating and Cooling
Supply, Inc., Total Supply, Inc., Valley Supply, Inc., Ener-Tech, Inc., Florida
Cooling Supply, Inc., and Lifetime Filters, Inc., in an aggregate amount up to
$18,000,000, subject to the terms and conditions summarized below:

BORROWER:        ACR Group, Inc. ("ACR") and each of its subsidiaries, ACR
                 Supply, Inc., Heating and Cooling Supply, Inc., Total Supply,
                 Inc., Valley Supply, Inc., Ener-Tech Inc., Florida Cooling
                 Supply, Inc., and Lifetime Filters, Inc. (ACR and the above
                 named subsidiaries hereinafter each a "Borrower" and
                 collectively "Borrowers")

FACILITY:        Credit Limit: Aggregate $18,000,000.00 revolving credit
                 facilities (collectively the "Facility"), including
                 $1,000,000.00 sub-facility for letters of credit available for
                 use by any, Borrower, subject to its respective eligible
                 collateral availability, provided that the aggregate amount
                 outstanding to all Borrowers under the Facility at any time
                 shall not exceed $18,000,000.00. See "Loan Availability" and
                 "Letters of Credit" below.

PURPOSE:         Refinance of certain existing debt owing to Lender, working
                 capital, issuance of letters of credit and acquisitions.

LOAN
AVAILABILITY:    Advances to each Borrower under the Facility will be limited
                 to the sum of (a) 85% of eligible accounts of such Borrower,
                 plus (b) 50% of eligible inventory, of such Borrower (provided
                 that the aggregate amount available for borrowing under the
                 Facility under this clause (b) shall not exceed
                 $9,000,000.00). Standards and determination of eligibility,
                 and applicable reserves from eligibility, shall be established
                 from time to time in the discretion of Lender.

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ACR Group, Inc.
May 12, 1997
Page 2

SECURITY:        All obligations and indebtedness from time to time owing under
                 the Facility shall be secured by first, prior and exclusive
                 security interests in all accounts, inventory, documents,
                 chattel paper, instruments, deposit accounts, contract rights
                 and general intangibles now owned or hereafter acquired by
                 each Borrower, and any and all proceeds thereof, as more
                 particularly described in the governing credit agreements
                 evidencing the Facility. All collateral will
                 cross-collateralize all obligations owing by each Borrower to
                 Lender.

LETTERS OF
CREDIT:          The Facility may be utilized by any Borrower to support the
                 issuance of letters of credit, subject to availability of
                 eligible collateral of such Borrower, up to the aggregate
                 maximum unfunded face amount at any time outstanding for the
                 account of all Borrowers of $1,000,000.00. Each letter of
                 credit shall be supported by a duly executed letter of credit
                 application and reimbursement agreement in form satisfactory
                 to Lender. The amount, if any, from time to time funded by
                 Lender under any such letters of credit shall be payable on
                 demand, or at Lender's option, charged as a loan under the
                 Facility in favor of the Borrower for whose account such
                 letter of credit was issued. The aggregate amount from time to
                 time outstanding for the account of any Borrower under letters
                 of credit shall be added to the amount outstanding so such
                 Borrower under the Facility for purposes of determining unused
                 availability under the Facility.

MATURITY:        Initial term of three (3) years, automatically extending for 
                 one year periods thereafter (subject to continued credit 
                 approval), each extending through the day preceding each 
                 successive the anniversary of the expiration of such initial 
                 term, unless notice of termination is provided by either party
                 at least sixty (60) days prior to any such anniversary date.

                 In the event that the Facility is terminated other than at the
                 end of the initial term in or any extended term, Borrowers
                 shall pay to Lender, as liquidated damages resulting from such
                 termination, an amount equal to the following applicable
                 percentage of the aggregate credit limit under the Facility:
                 (i) three percent (3.0%) if such termination occurs during the
                 first year following closing; (ii) two percent (2.0%) if such
                 termination occurs during the second year following closing;
                 and (iii) one percent (1%) at any time thereafter.

INTEREST RATE:   At Borrowers' option: (i) Lender's Prime Rate (as defined in
                 the governing credit agreements) plus one half of one percent
                 (0.50%) and/or (ii) LIBOR (as defined and adjusted in the
                 governing edit agreements) plus three percent (3.00%) (subject
                 to applicable maximum legal interest rates). Changes in the
                 applicable rate of interest based on


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ACR Group, Inc.
May 12, 1997
Page 3

                 the Prime Rate would be effective as of the first day of the
                 month following any change in the Prime Rate.  Interest would 
                 be calculated on the basis of a year of 360 days, subject to
                 applicable maximum legal interest rates. In order to reimburse
                 Lender for the cost of delays the collection and clearance of
                 remittances applied to the loan, accrued interest would be
                 calculated as if each such remittance had been received two
                 business days subsequent to its actual receipt.

CLOSING
FEE:             At closing, in consideration for establishing the Facility
                 and Lender's commitment thereunder, Borrowers shall pay to
                 Lender a commitment fee of $70,000.00 at the time of execution
                 and delivery of definitive credit agreements establishing the
                 Facility (payment thereof to be allocated among each Borrower
                 as determined by Borrowers in a manner which is acceptable to
                 Lender). Such fee shall be deemed earned when payable and
                 shall be non-refundable.

ADMINISTRATION &
FIELD EXAMINATION
FEE:             In consideration for Lender's administration of the Facility,
                 Borrowers shall pay to Lender a quarterly fee of $4,200 to
                 cover field examinations and other costs associated with the
                 administration of the Facility, payable quarterly in arrears
                 (payment thereof to be allocated among each Borrower as
                 determined by Borrowers in a manner which is acceptable to
                 Lender).


LETTER OF CREDIT
FEE:             The greater of one and one-half percent (1.50%) per annum for
                 standby letters of credit or Lender's minimum issuance fee.

COVENANTS:       The following covenants in respect of financial position shall
                 apply, in each case determined on a consolidated basis for 
                 ACR and its consolidated subsidiaries (financial covenant 
                 terms to be defined in the governing credit agreements 
                 evidencing the Facility:)

                 Leverage Ratio: Maximum ratio of total liabilities less
                 subordinated debt to tangible net worth plus subordinated debt
                 of 6.5 to 1.0. Step-down in the ratio to be mutually agreed
                 upon.

                 Tangible Net Worth. Tangible net worth to be determined.
                 Annual step-up provision equal to fifty percent (50%) of net
                 income after taxes.

                 Fixed Charge Coverage Ratio. A minimum fixed charge coverage
                 ratio of at least 1.1 to 1, measured as of the end of each
                 calendar month based on rolling previous twelve (12) months of
                 operations.
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ACR Group, Inc.
May 12,1997
Page 4

                 Minimum Availability. Minimum availability of at least
                 $200,000 during the period of each fiscal year comprised by
                 the calendar months of December through February.

                 Capital expenditures. Maximum amount of $250,000 annually.

                 Net Income. Net Income shall not be less than $0.00 for any
                 period of more than three consecutive calendar months.

OTHER TERMS:     Except as otherwise agreed by Lender:

                 1.       Borrowers shall provide Lender with the following
                 reporting (for ACR and its consolidated subsidiaries):

                          a.       Monthly consolidated and consolidating
                          financial statements, prepared in conformance with
                          generally accepted accounting principles, within 30
                          days of the end of each calendar month, accompanied
                          by a certification from each Borrower evidencing
                          compliance with all representations, warranties, and
                          covenants contained in the governing credit
                          agreements.

                          b.      Annual audited financial statements
                          (consolidated and consolidating), prepared in
                          conformance with generally accepted accounting
                          principles, within 120 days after the end of each
                          fiscal year, accompanied by a certification from each
                          Borrower evidencing compliance with all
                          representations, warranties, and covenants contained
                          in the governing credit agreements.

                          c.      Collateral and borrowing base reports by each
                          Borrower, as requested.

                          d.       Monthly certificate confirming compliance
                          with all covenants and requirements under the
                          governing credit agreements, signed by an officer of
                          each Borrower.

                          e.      Accounts receivable aging report and
                          inventory report for each Borrower, in form
                          satisfactory to Lender, within 30 days after the end
                          of each calendar month.

                 2.       Borrowers' accounting policies and practices shall
                 conform to generally accepted accounting principles. Each
                 Borrower shall keep and maintain proper, complete and
                 consistent books of record and account respecting its
                 operations, affairs and financial condition and shall permit
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ACR Group, Inc.
May 12, 1997
Page 5

                 Lender from time to time, by and through its authorized
                 agents, to visit and inspect any of it properties, inspect and
                 copy its books and records, and discuss its affairs, finances,
                 accounts, and operations with its officers.

                 3.       On and after the date of initial funding, all
                 remittances to each Borrower in payment of accounts will be
                 directed to Lender, for collection and application (on a
                 periodic basis acceptable to Borrowers and Lender) in
                 reduction of the loan balance of such Borrower under the
                 Facility.

                 4.       Each Borrower will maintain and preserve its
                 corporate existence and all rights, privileges, franchises and
                 other authority for the conduct of its business.

                 5.       Each Borrower will maintain its properties and
                 facilities in good order and repair.

                 6.       Borrowers will maintain insurance with responsible
                 insurance carriers against such risks and in such amounts as
                 is customary for similar businesses, naming Lender as loss
                 payee, in form satisfactory to Lender.

                 7.       Borrowers will pay and discharge all taxes,
                 assessments and governmental charges in a timely manner,
                 except those being contested in good faith with adequate
                 reserves satisfactory to Lender.

                 8.       Borrowers will provide Lender with annual projections
                 of each Borrower's anticipated financial performance for the
                 succeeding year.

                 9.       Borrowers shall furnish waivers from all landlords,
                 mortgagees or other third party potential lien claimants as
                 may be requested by Lender with respect to each premises where
                 any of Lender's collateral is located, which shall be in form
                 satisfactory to Lender.

                 10.      The governing credit agreements will specify
                 customary events of default and remedies as may be required 
                 by Lender. All obligations from time to time owing to Lender 
                 by Borrowers shall be cross-defaulted.

                 11.      The governing credit agreements and all related legal
                 documentation will be governed by the laws of the State of
                 Texas.

                 12.      Borrowers will reimburse Lender for all costs and
                 expenses, including without limitation, attorney's fees and
                 other out-of-pocket
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ACR Group, Inc.
May 12, 1997
Page 6
                 costs, incurred in connection with the governing agreements
                 evidencing the Facility and the ongoing administration or
                 enforcement of the Facility.

CONDITIONS
FOR CLOSING:     1.       Borrowers will execute and deliver all definitive
                 legal documentation relative to the Facility as may be
                 required by Lender. All legal documentation in respect of the
                 Facility shall be acceptable to Lender in its sole discretion.
                 Such legal documentation shall contain conditions, covenants
                 and other provisions (in addition to those specified above)
                 customary for credit facilities of this type including,
                 without limitation, conditions for funding and provisions
                 addressing: (i) litigation, claims and contingent liabilities,
                 (ii) incurrence of other indebtedness, lease obligations or
                 contingent liabilities, (iii) investments, (iv) transactions
                 with affiliates, (v) subordination of obligations owing to
                 affiliates, (vi) payment of subordinated debt, (vii) material
                 change in management or ownership, (viii) merger or
                 consolidation, (ix) repurchase or redemption of capital stock,
                 (x) liens on assets, (xi) dividends, (xii) acquisitions,
                 (xiii) compliance with applicable laws, and other provisions
                 customary for similar credit facilities as Lender shall
                 require. Lender will require an acceptable opinion of counsel
                 for Borrowers, addressing such matters as Lender may
                 designate.

                 2.       There is no material adverse change in the financial
                 condition, assets, liabilities, business, results of
                 operations or projected operations of any Borrower, or of
                 Borrowers taken as a whole, since the effective date of the
                 last financial statements and other financial and operating
                 information submitted to Lender, such determination to be made
                 according to Lender's subjective opinion in its discretion.

                 3.       Lender shall complete a field audit of Borrowers'
                 operations, the results of which shall be satisfactory to
                 Lender.

                 4.       Lender shall obtain a copy of Borrowers' audited
                 financial statement for the fiscal year ended February 28,
                 1997, which shall reflect no material adverse change relative
                 to the draft copy thereof delivered to Lender by Borrowers.

                 5.       Confirmation to Lender that each Borrower is a
                 corporation duly formed and validly existing and presentation 
                 of documentation regarding authority to act and authorization 
                 of the transaction and all documentation.

                 6.       Evidence of insurance in compliance with the
                 requirements of this commitment.
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ACR Group, Inc.
May 12, 1997
Page 7

                 7.       Lender shall confirm to its satisfaction the absence
                 of other liens or security interests on the collateral.

                 8.       Verification by Lender of Lender's first priority
                 security interest and lien in all collateral.

                 9.       Payment to Lender of all expenses and costs,
                 including without limitation, reasonable fees and costs of
                 Lender's counsel, incurred by Lender in connection with
                 preparation of this letter and documenting and establishing
                 the Facility.

                 10.      The accomplishment of all requirements and conditions
                 stated in this letter.

The foregoing is intended to provide a substantive outline of the Facility and
is not intended as a complete statement of all terms, conditions and documents
that will be required in connection with  the transaction. Our approval is
expressly conditioned upon the satisfaction of Lender in its discretion of all
legal documentation and the furnishing by Borrowers to Lender of such
documentation, information, certifications and opinions as Lender may request
in connection with establishing the Facility. It is expressly understood that
such legal documentation, when executed by Borrowers and Lender, shall
constitute the final and complete agreement between Lender and Borrowers
regarding the subject matter hereof and shall supersede all of the provisions
hereof. Nothing contained in this letter shall alter, amend, change or modify
such loan documents, nor shall anything contained herein be construed as an
agreement or commitment except as specifically provided herein. This approval
may be withdrawn by Lender at any time if Lender discovers that any material
misrepresentations have been made to Lender by any Borrower, or if any material
facts come to our attention which we reasonably believe adversely affects our
evaluation of the collateral or of any Borrower, or of Borrowers as a whole, or
of the creditworthiness, financial condition or operations of any Borrower, or
of Borrowers as a whole.

We are pleased to have the opportunity to work with you to complete this
financing. Please indicate your acceptance of this letter by signing and
returning the enclosed copy on or before 5:00 p.m., May 15, 1997, together with
your check in the amount of $15,000.00 as a deposit against costs, expenses and
professional fees incurred by Lender in connection with the Facilities, at
which time, if not accepted, this confirmation approval will automatically
terminate without notice and be of no further effect. Further, after such
acceptance in the event this Facility is not consummated on or before July 15,
1997 this approval confirmation shall automatically terminate without notice
unless extended by mutual agreement in writing. By accepting this letter,
Borrowers agree to pay all out-of-pocket costs and expenses incurred by Lender
in connection with preparations to establish the Facility, including, without
limitation, reasonable at attorneys' fees and costs in preparation of this
letter and preparation of documentation and closing, and all other costs
incurred in connection therewith, whether or not the Facility is consummated.

This letter is intended for you only and may not be relied upon by any third
party.
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ACR Group, Inc.
May 12, 1997
Page 8

       THIS WRITTEN AGREEMENT REPRESENTS THE FINAL AGREEMENT BETWEEN THE
       PARTIES AND MAY NOT BE CONTRADICTED BY EVIDENCE OF PRIOR,
       CONTEMPORANEOUS OR SUBSEQUENT ORAL AGREEMENTS BETWEEN THE PARTIES.

Sincerely,

NATIONSBANK OF TEXAS, N.A.

By:/s/ CATHY BARROW        
---------------------------
       Cathy Barrow
       Vice President

ACCEPTED this 13th day of May, 1997.

ACR GROUP, INC.


By: /s/ ANTHONY R. MARESCA
---------------------------
Name:   Anthony R. Maresca
---------------------------
Title:  Sr. Vice President
---------------------------


cc:     Jim Recer
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[NationsBank Letterhead]




June 10, 1997


Mr. Anthony R. Maresca
Senior Vice President
ACR Group, Inc.
3200 Wilcrest Drive, Suite 440
Houston, Texas 77042

RE:     Amendment to Letter of May 12, 1997 concerning Credit Facility for ACR
        Group, Inc. and Subsidiaries


Dear Tony:

As clarification of Condition 2 of the Conditions of Closing and in accordance
with our discussions, Lender hereby defines material adverse change as a decline
in the consolidated shareholder's equity of more than $150,000.

Please call me if you have any questions.


Sincerely,


/s/  CATHY BARLOW


Cathy Barlow
Vice President

cc:     Dora Martinez