Comfort Systems USA (FIX) 10-K 2013 FY Annual report

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EXHIBIT 21.1

SUBSIDIARIES OF COMFORT SYSTEMS USA, INC.

ENTITY NAME	DOMESTIC JURISDICTION	FORMATION DATE
ACI Mechanical, Inc.	Delaware		06/26/1998
ARC Comfort Systems USA, Inc.	Delaware		03/17/1998
Accu-Temp GP, Inc.	Delaware		05/21/1998
Accu-Temp LP, Inc.	Delaware		05/20/1998
Acorn Industrial, LLC	North Carolina		01/03/1997
Air Systems Engineering, Inc.	Washington		05/18/1973
AirTemp, Inc.	Maine		10/15/1998
Atlas-Accurate Holdings, L.L.C.	Delaware		12/28/1998
Atlas Comfort Systems USA, Inc.	California		07/31/2007
Atlas Comfort Systems USA, L.L.C.	Delaware		06/08/2007
Batchelor's Mechanical Contractors, LLC	Alabama		03/16/1981
BCM Controls Corporation	Massachusetts		10/03/1984
California Comfort Systems USA, Inc.	California		05/18/1983
ColonialWebb Contractors Company	Virginia		03/30/1972
Comfort Systems USA (Arkansas), Inc.	Delaware		03/17/1998
Comfort Systems USA (Baltimore), LLC	Delaware		10/15/1998
Comfort Systems USA (Bristol), Inc.	Delaware		08/25/1997
Comfort Systems USA (Carolinas), LLC	North Carolina		01/01/2011
Comfort Systems USA Energy Services, Inc.	Delaware		08/25/1997
Comfort Systems USA G.P., Inc.	Delaware		08/12/1998
Comfort Systems USA (Intermountain), Inc.	Utah		05/06/1969
Comfort Systems USA (Kentucky), Inc.	Kentucky		02/10/1981
Comfort Systems USA (MidAtlantic), LLC	Virginia		01/01/2010
Comfort Systems USA (Midwest), LLC	Iowa		10/13/2009
Comfort Systems USA National Accounts, LLC	Indiana		07/28/1998
Comfort Systems USA (Ohio), Inc.	Ohio		10/10/1979
Comfort Systems USA (Pasadena), Inc.	Texas		06/28/2007
Comfort Systems USA Puerto Rico, Inc.	Puerto Rico		08/09/1991
Comfort Systems USA (South Central), Inc.	Texas		06/22/2007
Comfort Systems USA (Southeast), Inc.	Delaware		03/24/1998
Comfort Systems USA (Southwest), Inc.	Arizona		12/23/1977
Comfort Systems USA (Syracuse), Inc.	New York		03/08/1965
Comfort Systems USA (Texas), L.P.	Texas		08/14/1998
Comfort Systems USA (Western Michigan), Inc.	Michigan		07/21/1989
Control Concepts, LLC	Georgia		12/16/1996
Control Concepts Mechanical Services, LLC	Georgia		01/17/2008
CS53 Acquisition Corp.	Delaware		01/26/1999
Delcard Associates, LLC	Delaware		06/23/2000
Design Mechanical Incorporated	Delaware		10/30/1997
Dillingham & Smith Mechanical and Sheet Metal Contractors, LLC	Tennessee		12/31/2003
Eastern Heating & Cooling, Inc.	New York		12/19/1988
Eastern Refrigeration Co., Inc.	New York		01/30/1990
Environmental Air Systems, LLC	North Carolina		10/07/2011
Envirotrol, LLC	North Carolina		10/27/2011
Granite State Holdings Company, Inc.	Delaware		11/02/2005
Granite State Plumbing & Heating, LLC	Delaware		07/31/2001
H & M Mechanical, Inc.	Delaware		06/25/1998
Helm Corporation	Colorado		10/26/1972

ENTITY NAME	DOMESTIC JURISDICTION	FORMATION DATE
Hess Mechanical Corporation	Delaware		03/17/1998
Hudson River Heating and Cooling, Inc.	Delaware		08/19/2005
H-VAC Supply, L.L.C.	Puerto Rico		10/18/2006
Mechanical Technical Services, Inc.	Texas		06/22/2007
Merit Mechanical, Inc.	Washington		02/14/1984
MJ Mechanical Services, Inc.	Delaware		12/12/1997
North American Mechanical, Inc.	Delaware		03/17/1998
Plant Services Incorporated	Iowa		07/02/1986
Quality Air Heating and Cooling, Inc.	Michigan		09/10/1980
Riddleberger Brothers, Inc.	Virginia		12/22/1958
S.I. Goldman Company, Inc.	Florida		10/04/1976
S.M. Lawrence Company, Inc.	Tennessee		03/08/1973
SA Associates, Inc.	Utah		03/27/1984
Salmon & Alder, LLC	Utah		07/08/1996
Seasonair, Inc.	Maryland		10/28/1966
Temp-Right Service, Inc.	Delaware		09/25/1997
The Capital Refrigeration Company	Delaware		08/06/1998

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EXHIBIT 21.1

SUBSIDIARIES OF COMFORT SYSTEMS USA, INC.