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Exhibit 99.1 COMFORT SYSTEMS USA CONTACT : William George , CFO ( 713-830-9650 ) Julie Shaeff , CAO ( 713-830-9687 ) ir@comfortsystemsusa.com FOR IMMEDIATE RELEASE 675 Bering Drive , Suite 400 Houston , Texas 77057 713-830-9600 COMFORT SYSTEMS USA REPORTS FIRST QUARTER 2021 RESULTS Houston , TX - April 28 , 2021 - Comfort Systems USA , Inc. ( NYSE : FIX ) today reported results for the quarter ended March 31 , 2021 . For the quarter ended March 31 , 2021 , net income was $ 26.5 million , or $ 0.73 per diluted share , as compared to $ 17.7 million , or $ 0.48 per diluted share , for the quarter ended March 31 , 2020. Revenue for the first quarter of 2021 was $ 669.8 million compared to $ 700.1 million in 2020. The Company reported operating cash flow of $ 84.6 million in the current quarter compared to $ 21.9 million in 2020 . Backlog as of March 31 , 2021 was $ 1.66 billion as compared to $ 1.51 billion as of December 31 , 2020 and $ 1.62 billion as of March 31 , 2020. On a same - store basis , backlog decreased from $ 1.62 billion as of March 31 , 2020 to $ 1.34 billion as of March 31 , 2021 . Brian Lane , Comfort Systems USA's President and Chief Executive Officer , said , “ We are happy to report a strong start to 2021 with increases in earnings , cash flow , and sequential backlog . Our earnings significantly exceed the first quarter of 2020 , which was the quarter last year that was most negatively impacted by the global pandemic . Our essential workforce continues to perform beyond all expectations , and we are grateful for their courage and perseverance . " Mr. Lane continued , “ Our backlog strengthened this quarter as compared to year end . Although we are still experiencing some delays in bookings and starts , we see good signs that first half headwinds are subsiding . Our pipeline and bidding activity remain strong . Cash flow was unprecedented for a first quarter as a result of strong execution as well as the receipt of large advance payments for certain orders and projects . " Mr. Lane concluded , “ The sporadic air pockets that were caused by the pandemic seem to be abating , and we look forward to continued strong results for the balance of 2021. We perceive good trends in underlying activity levels , especially in our industrial , technology and modular markets , and we are optimistic about our prospects for the next several quarters . The Company will host a webcast and conference call to discuss its financial results and position on Thursday , April 29 , 2021 at 10:30 a.m. Central Time . The call - in number for this conference call is 1-888-713-4218 , and the passcode is 52608066. The call and the slide presentation to accompany the remarks can be accessed on the Company's website at www.comfortsystemsusa.com under the Investor tab . A replay of the entire call will be available on the Company's website on the next business day following the call . Comfort Systems USA® is a leading provider of commercial , industrial and institutional heating , ventilation , air conditioning and electrical contracting services , with 139 locations in 113 cities around the nation . For more information , visit the Company's website at www.comfortsystemsusa.com .