LIMITED POWER OF ATTORNEY FOR SECTION 16 REPORTING OBLIGATIONS

The  undersigned  hereby  makes,  constitutes,  and appoints Laura F. Howell and
Rachel J. Reagor, each acting individually, as the undersigned's true and lawful
attorney-in-fact,  with  full  power  and  authority as hereinafter described on
behalf of and in the name, place, and stead of the undersigned to:

   (1) prepare,  execute,  acknowledge,  deliver,  and  file  Forms  3, 4, and 5
       (including  any  amendments  thereto)  with  respect to the securities of
       Comfort  Systems  USA, Inc., a Delaware corporation (the "Company"), with
       the  United  States  Securities  and  Exchange  Commission,  any national
       securities  exchanges,  and  the  Company,  as  considered  necessary  or
       advisable  under Section 16(a) of the Securities Exchange Act of 1934 and
       the rules and regulations promulgated thereunder, as amended from time to
       time (the "Exchange Act");

   (2) seek   or   obtain,  as  the  undersigned's  representative  and  on  the
       undersigned's  behalf,  information  on  transactions  in  the  Company's
       securities from any third party, including brokers, employee benefit plan
       administrators,  and  trustees, and the undersigned hereby authorizes any
       such  person  to release any such information to the attorney-in-fact and
       approves and ratifies any such release of information; and

   (3) perform  any  and  all  other  acts  that,  in  the  discretion  of  such
       attorney-in-fact,  are  necessary  or  desirable for and on behalf of the
       undersigned in connection with the foregoing.

The undersigned acknowledges that:

   (1) this   Power   of   Attorney  authorizes,  but  does  not  require,  such
       attorney-in-fact  to act in his or her discretion on information provided
       to   such  attorney-in-fact  without  independent  verification  of  such
       information;

   (2) any documents prepared and/or executed by such attorney-in-fact on behalf
       of  the  undersigned  pursuant  to this Power of Attorney will be in such
       form   and   will   contain  such  information  and  disclosure  as  such
       attorney-in-fact, in his or her discretion, deems necessary or desirable;

   (3) neither  the  Company nor such attorney-in-fact assumes (i) any liability
       for  the  undersigned's  responsibility to comply with the requirement of
       the  Exchange  Act, (ii) any liability of the undersigned for any failure
       to comply with such requirements, or (iii) any obligation or liability of
       the  undersigned  for  profit  disgorgement  under  Section  16(b) of the
       Exchange Act; and

   (4) this   Power   of   Attorney   does  not  relieve  the  undersigned  from
       responsibility  for  compliance  with the undersigned's obligations under
       the Exchange Act, including without limitation the reporting requirements
       under Section 16 of the Exchange Act.

The  undersigned  hereby  gives  and  grants the foregoing attorney-in-fact full
power  and  authority  to  do and perform all and every act and thing whatsoever
requisite,  necessary,  or  appropriate  to  be  done in and about the foregoing
matters  as  fully to all intents and purposes as the undersigned might or could
do  if  present,  hereby ratifying all that such attorney-in-fact of, for, or on
behalf  of  the  undersigned, shall lawfully do or cause to be done by virtue of
this Limited Power of Attorney.

This  Power  of  Attorney  shall  remain  in  full  force  and  effect until the
undersigned  is no longer required to file Forms 3, 4, and 5 with respect to the
undersigned's  holdings of and transactions in securities issued by the Company,
unless  earlier  revoked by the undersigned in a signed writing delivered to the
foregoing attorney-in-fact.

IN  WITNESS  WHEREOF,  the  undersigned  has caused this Power of Attorney to be
executed in Harris County, Texas as of this 6th date of March, 2019.

                                                   /s/ Herman E. Bulls
                                                   -----------------------------
                                                   Herman E. Bulls