ITEM 6.    Selected Financial Data

        The following selected historical financial data has been derived from our audited financial statements and should be read in conjunction with the historical Consolidated Financial Statements and related notes:

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ITEM 7.    Management's Discussion and Analysis of Financial Condition and Results of Operations

        The following discussion and analysis should be read in conjunction with the Consolidated Financial Statements and related notes included elsewhere in this annual report on Form 10-K. Also see "Forward-Looking Statements" discussion.

Introduction and Overview

        We are a national provider of comprehensive HVAC installation, maintenance, repair and replacement services within the mechanical services industry. The services we provide address a very broad need, as air is circulated through almost all commercial, industrial and institutional buildings virtually year-round. We operate primarily in the commercial, industrial and institutional HVAC markets and perform most of our services within office buildings, retail centers, apartment complexes, manufacturing plants, and healthcare, education and government facilities. In addition to standard HVAC services, we provide specialized applications such as building automation control systems, fire protection, process cooling, electronic monitoring and process piping. Certain locations also perform related activities such as electrical service and plumbing.

Nature and Economics of Our Business

        Approximately 85% of our revenues are earned on a project basis for installation of HVAC systems in newly constructed facilities or for replacement of HVAC systems in existing facilities. Customers hire us to ensure such systems deliver specified or generally expected heating, cooling, conditioning and circulation of air in a facility. This entails installing core system equipment such as packaged heating and air conditioning units, or in the case of larger facilities, separate core components such as chillers, boilers, air handlers, and cooling towers. We also typically install connecting and distribution elements such as piping and ducting. Our responsibilities usually require conforming the systems to pre-established engineering drawings and equipment and performance specifications, which we frequently participate in establishing. Our project management responsibilities include staging equipment and materials to project sites, deploying labor to perform the work, and coordinating with other service providers on the project, including any subcontractors we might use to deliver our portion of the work.

        When competing for project business, we usually estimate the costs we will incur on a project, and then propose a bid to the customer that includes a contract price and other performance and payment terms. Our bid price and terms are intended to cover our estimated costs on the project and provide a profit margin to us commensurate with the value of the installed system to the customer, the risk that project costs or duration will vary from estimate, the schedule on which we will be paid, the opportunities for other work that we might forego by committing capacity to this project, and other costs that we incur more broadly to support our operations but which are not specific to the project. Typically customers will seek bids from competitors for a given project. While the criteria on which customers select the winning bid vary widely and include factors such as quality, technical expertise, on-time performance, post-project support and service, and company history and financial strength, we believe that price is the most influential factor for most customers in choosing an HVAC installation and service provider.

        After a customer accepts our bid, we generally enter into a contract with the customer that specifies what we will deliver on the project, what our related responsibilities are, and how much and when we will be paid. Our overall price for the project is typically set at a fixed amount in the contract, although changes in project specifications or work conditions that result in unexpected additional work are usually subject to additional payment from the customer via what are commonly known as change orders. Project contracts typically provide for periodic billings to the customer as we meet progress milestones or incur cost on the project. Project contracts in our industry also frequently allow for a

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small portion of progress billings or contract price to be withheld by the customer until after we have completed the work, typically for six months. Amounts withheld under this practice are known as retention or retainage.

        Labor and overhead costs account for the majority of our cost of service. Accordingly, labor management and utilization have the most impact on our project performance. Given the fixed price nature of much of our project work, if our initial estimate of project costs is wrong or we incur cost overruns that cannot be recovered in change orders, we can experience reduced profits or even significant losses on fixed price project work. We also perform some project work on a cost-plus or a time and materials basis, under which we are paid our costs incurred plus an agreed-upon profit margin. These margins are typically less than fixed-price contract margins because there is less risk of unrecoverable cost overruns in cost-plus or time and materials work.

        As of December 31, 2009, we had 4,561 projects in process. Our average project takes six to nine months to complete, with an average contract price of approximately $420,000. Our projects generally require working capital funding of equipment and labor costs. Customer payments on periodic billings generally do not recover these costs until late in the job. Our average project duration together with typical retention terms as discussed above generally allow us to complete the realization of revenue and earnings in cash within one year. We have what we believe is a well-diversified distribution of revenues across end-use sectors that we believe reduces our exposure to negative developments in any given sector. Because of the integral nature of HVAC and related controls systems to most buildings, we have the legal right in almost all cases to attach liens to buildings or related funding sources when we have not been fully paid for installing systems, except with respect to some government buildings. The service work that we do, which is discussed further below, usually does not give rise to lien rights.

        We also perform larger HVAC projects. As of December 31, 2009, we had 6 projects in process with a contract price of between $15 and $31 million, 19 projects between $10 million and $15 million, 53 projects between $5 million and $10 million, and 241 projects between $1 million and $5 million. Taken together, projects with contract prices of $1 million or more totaled $1,286.0 million of aggregate contract value as of December 31, 2009, or approximately 67%, out of a total contract value for all projects in progress of $1,924.8 million. Generally, projects closer in size to $1 million will be completed in one year or less. It is unusual for us to work on a project that exceeds two years in length.

        In addition to project work, approximately 15% of our revenues represent maintenance and repair service on already-installed HVAC and controls systems. This kind of work usually takes from a few hours to a few days to perform. Prices to the customer are usually based on the equipment and materials used in the service as well as technician labor time. We usually bill the customer for service work when it is complete, typically with payment terms of up to thirty days. We also provide maintenance and repair service under ongoing contracts. Under these contracts, we are paid regular monthly or quarterly amounts and provide specified service based on customer requirements. These agreements typically cover periods ranging from one to three years and are cancelable on 30 to 60 days notice.

        A relatively small portion of our revenues comes from national and regional account customers. These customers typically have multiple sites, and contract with us to perform maintenance and repair service. These contracts may also provide for us to perform new or replacement systems installation. We operate a national call center to dispatch technicians to sites requiring service. We perform the majority of this work with our own employees, with the balance being subcontracted to third parties that meet our performance qualifications. We will also typically use proprietary information systems to maintain information on the customer's sites and equipment, including performance and service records, and related cost data. These systems track the status of ongoing service and installation work,

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and may also monitor system performance data. Under these contractual relationships, we usually provide consolidated billing and credit payment terms to the customer.

Profile and Management of Our Operations

        We manage our 43 operating units based on a variety of factors. Financial measures we emphasize include profitability, and use of capital as indicated by cash flow and by other measures of working capital principally involving project cost, billings and receivables. We also monitor selling, general, administrative and indirect project support expense, backlog, workforce size and mix, growth in revenues and profits, variation of actual project cost from original estimate, and overall financial performance in comparison to budget and updated forecasts. Operational factors we emphasize include project selection, estimating, pricing, management and execution practices, labor utilization, safety, training, and the make-up of both existing backlog as well as new business being pursued, in terms of project size, technical application and facility type, end-use customers and industries, and location of the work.

        Most of our operations compete on a local or regional basis. Attracting and retaining effective operating unit managers is an important factor in our business, particularly in view of the relative uniqueness of each market and operation, the importance of relationships with customers and other market participants such as architects and consulting engineers, and the high degree of competition and low barriers to entry in most of our markets. Accordingly, we devote considerable attention to operating unit management quality, stability, and contingency planning, including related considerations of compensation, and non-competition protection where applicable.

Economic and Industry Factors

        As an HVAC and building controls services provider, we operate in the broader nonresidential construction services industry and are affected by trends in this sector. While we do not have operations in all major cities of the United States, we believe our national presence is sufficiently large that we experience trends in demand for and pricing of our services that are consistent with trends in the national nonresidential construction sector. As a result, we monitor the views of major construction sector forecasters along with macroeconomic factors they believe drive the sector, including trends in gross domestic product, interest rates, business investment, employment, demographics, and the general fiscal condition of federal, state and local governments. Although nonresidential construction activity has demonstrated periods of both significant growth and decline, it has grown at a compound annual rate of approximately 4.2% over the last twenty-five years.

        Spending decisions for building construction, renovation and system replacement are generally made on a project basis, usually with some degree of discretion as to when and if projects proceed. With larger amounts of capital, time, and discretion involved, spending decisions are affected to a significant degree by uncertainty, particularly concerns about economic and financial conditions and trends. We have experienced periods of time when economic weakness caused a significant slowdown in decisions to proceed with installation and replacement project work.

Operating Environment and Management Emphasis

        Nonresidential building construction and renovation activity, as reported by the federal government, declined over the three year period of 2001 to 2003, expanded moderately during 2004 and 2005, and was strong over the three year period from 2006 to 2008. During the decline and through 2003, we responded to market challenges by pursuing work in sectors less affected by this downturn, such as government, educational, and health care facilities, and by establishing marketing initiatives that take advantage of our size and range of expertise. We also responded to declining gross profits over those years by reducing our selling, general, and administrative expenses, and our indirect

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project and service overhead costs. We believe our efforts in these areas partially offset the decline in our profitability over that period. We have experienced notable improvements in both industry activity as well as our own results from 2004 to 2008.

        As a result of our continued strong emphasis on cash flow, our debt outstanding under our revolving credit facility is zero, and we have substantial uncommitted cash balances, as discussed further in "Liquidity and Capital Resources" below. We have a credit facility in place with considerably less restrictive terms than those of our previous facilities; this facility does not expire until February 2012. We have strong surety relationships to support our bonding needs, and we believe our relationships with the surety markets are positive in light of our strong current results and financial position. We have generated positive free cash flow in each of the last ten calendar years and will continue our emphasis in this area. We believe that the relative size and strength of our balance sheet and surety support as compared to most companies in our industry represent competitive advantages for us.

        As discussed at greater length in "Results of Operations" below, we have seen declining activity levels in our industry since late 2008 and we expect price competition to continue to be strong, as local and regional competitors respond cautiously to changing conditions. We will continue our efforts to find the more active sectors in our markets, and to increase our regional and national account business. Our primary emphasis for 2010 will be on execution and cost control, and on maintaining levels that will permit us to earn reasonable profits while preserving our core workforce. We have increased our focus on project qualification, estimating, pricing and management, and on service performance.

Critical Accounting Policies

        In response to the Commission's Release No. 33-8040, "Cautionary Advice Regarding Disclosure About Critical Accounting Policies," we identified our critical accounting policies based upon the significance of the accounting policy to our overall financial statement presentation, as well as the complexity of the accounting policy and our use of estimates and subjective assessments. We have concluded that our most critical accounting policy is our revenue recognition policy. As discussed elsewhere in this annual report on Form 10-K, our business has two service functions: (i) installation, which we account for under the percentage of completion method, and (ii) maintenance, repair and replacement, which we account for as the services are performed, or in the case of replacement, under the percentage of completion method. In addition, we identified other critical accounting policies related to our allowance for doubtful accounts receivable, the recording of our self-insurance liabilities, valuation of deferred tax assets and the recoverability of goodwill and identifiable intangible assets. These accounting policies, as well as others, are described in Note 2 to the Consolidated Financial Statements included elsewhere in this annual report on Form 10-K.

Percentage of Completion Method of Accounting

        Approximately 85% of our revenues were earned on a project basis and recognized through the percentage of completion method of accounting. Under this method contract revenue recognizable at any time during the life of a contract is determined by multiplying expected total contract revenue by the percentage of contract costs incurred at any time to total estimated contract costs. More specifically, as part of the negotiation and bidding process in which we engage in connection with obtaining installation contracts, we estimate our contract costs, which include all direct materials (exclusive of rebates), labor and subcontract costs and indirect costs related to contract performance, such as indirect labor, supplies, tools, repairs and depreciation costs. These contract costs are included in our results of operations under the caption "Cost of Services." Then, as we perform under those contracts, we measure such costs incurred, compare them to total estimated costs to complete the contract, and recognize a corresponding proportion of contract revenue. Labor costs are considered to be incurred as the work is performed. Subcontract labor is recognized as the work is performed, but is generally subjected to approval as to milestones or other evidence of completion. Non-labor project

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cost consists of purchased equipment, prefabricated materials and other materials. Purchased equipment on our projects is substantially produced to job specifications and is a value added element to our work. The costs are considered to be incurred when title is transferred to us, which typically is upon delivery to the worksite. Prefabricated materials, such as ductwork and piping, are generally performed at our shops and recognized as contract costs when fabricated for the unique specifications of the job. Other materials cost are not significant and are generally recorded when delivered to the worksite. This measurement and comparison process requires updates to the estimate of total costs to complete the contract, and these updates may include subjective assessments.

        We generally do not incur significant costs prior to receiving a contract, and therefore, these costs are expensed as incurred. In limited circumstances, when significant pre-contract costs are incurred, they are deferred if the costs can be directly associated with a specific contract and if their recoverability from the contract is probable. Upon receiving the contract, these costs are included in contract costs. Deferred costs associated with unsuccessful contract bids are written off in the period that we are informed that we will not be awarded the contract.

        Our contracts typically provide for a schedule of billings or invoices to the customer based on reaching agreed- upon milestones or as we incur costs. The schedules for such billings usually do not precisely match the schedule on which we incur costs. As a result, contract revenues recognized in the statement of operations can and usually do differ from amounts that can be billed or invoiced to the customer at any point during the contract. Amounts by which cumulative contract revenues recognized on a contract as of a given date exceed cumulative billings to the customer under the contract are reflected as a current asset in our balance sheet under the caption "Costs and estimated earnings in excess of billings." Amounts by which cumulative billings to the customer under a contract as of a given date exceed cumulative contract revenues recognized on the contract are reflected as a current liability in our balance sheet under the caption "Billings in excess of costs and estimated earnings."

        The percentage of completion method of accounting is also affected by changes in job performance, job conditions, and final contract settlements. These factors may result in revisions to estimated costs and, therefore, revenues. Such revisions are frequently based on further estimates and subjective assessments. We recognize these revisions in the period in which they are determined. If such revisions lead us to conclude that we will recognize a loss on a contract, the full amount of the estimated ultimate loss is recognized in the period we reach that conclusion, regardless of the percentage of completion of the contract.

        Revisions to project costs and conditions can give rise to change orders under which the customer agrees to pay additional contract price. Revisions can also result in claims we might make against the customer to recover project variances that have not been satisfactorily addressed through change orders with the customer. Except in certain circumstances, we do not recognize revenues or margin based on change orders or claims until they have been agreed upon with the customer. The amount of revenue associated with unapproved change orders and claims is currently immaterial. Variations from estimated project costs could have a significant impact on our operating results, depending on project size, and the recoverability of the variation via additional customer payments.

Accounting for Allowance for Doubtful Accounts

        We are required to estimate the collectability of accounts receivable and provide an allowance for doubtful accounts for receivable amounts we believe we will not ultimately collect. This requires us to make certain judgments and estimates involving, among others, the creditworthiness of the customer, our prior collection history with the customer, ongoing relationships with the customer, the aging of past due balances, our lien rights, if any, in the property where we performed the work, and the availability, if any, of payment bonds applicable to our contract. These estimates are re-evaluated and adjusted as additional information is received.

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Accounting for Self-Insurance Liabilities

        We are substantially self-insured for worker's compensation, employer's liability, auto liability, general liability and employee group health claims in view of the relatively high per-incident deductibles we absorb under our insurance arrangements for these risks. Losses up to deductible amounts are estimated and accrued based upon known facts, historical trends and industry averages. Loss estimates associated with the larger and longer-developing risks—worker's compensation, auto liability and general liability—are reviewed by a third party actuary quarterly. We believe these accruals are adequate. However, insurance liabilities are difficult to estimate due to unknown factors, including the severity of an injury, the determination of our liability in proportion to other parties, timely reporting of occurrences, ongoing treatment or loss mitigation, general trends in litigation recovery outcomes and the effectiveness of safety and risk management programs. Therefore, if actual experience differs from the assumptions and estimates used for recording the liabilities, adjustments may be required and would be recorded in the period that such experience becomes known.

Accounting for Deferred Tax Assets

        We regularly evaluate valuation allowances established for deferred tax assets for which future realization is uncertain. We perform this evaluation quarterly. Estimations of required valuation allowances include estimates of future taxable income. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which the activity underlying these assets becomes deductible. We consider projected future taxable income and tax planning strategies in making this assessment. If actual future taxable income differs from our estimates, we may not realize deferred tax assets to the extent we have estimated.

Recoverability of Goodwill and Identifiable Intangible Assets

        Goodwill is the excess of purchase cost over the fair value of the net assets of acquired businesses. We do not amortize goodwill. We assess our goodwill asset amounts for impairment each year, and more frequently if circumstances suggest that an impairment may have occurred. Impairment must be reflected when the value of a given business unit in excess of its tangible net assets falls below the goodwill asset balance carried for that unit on our books. If other business units have had increases in the value of their respective goodwill balances, such increases may not be recorded. Accordingly, such increases may not be netted against impairments at other business units. The requirements for assessing whether goodwill assets have been impaired involve market-based information. This information, and its use in assessing goodwill, entails some degree of subjective assessment.

        We currently perform our annual impairment testing as of October 1 and any impairment charges resulting from this process are reported in the fourth quarter. We segregate our operations into reporting units based on the degree of operating and financial independence of each unit and our related management of them. We perform our annual goodwill impairment testing at the reporting unit level. As of October 1, 2009, we had 41 reporting units of which 25 reporting units have a goodwill balance. These reporting units are tested for impairment by comparing each unit's fair value to its carrying value.

        We estimate the fair value of the reporting unit based on two market approaches and an income approach, which utilizes discounted future cash flows. Assumptions critical to the fair value estimates under the discounted cash flow model include discount rates, cash flow projections, projected long-term growth rates and the determination of terminal values. The market approaches utilized market multiples of invested capital from comparable publicly traded companies ("public company approach") and comparable transactions ("transaction approach"). The market multiples from invested capital include revenues, book equity plus debt and earnings before interest, taxes, depreciation and amortization ("EBITDA"). These assumptions are evaluated and updated on an annual basis. During

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2007 and 2008, we assigned a weighting of 40% to the discounted cash flow analysis, and a weighting of 30% for each of the market approaches. During 2009, we assigned a weighting of 40% to the discounted cash flow analysis, 60% to the public company approach and 0% to the transaction approach. There was no weighting assigned to the transaction approach due to the lack of comparable market data in 2009. There were no other changes in our methodologies for valuing goodwill during the current year.

        The fair value exceeded the carrying value by a significant margin for 24 of the 25 reporting units. There was one reporting unit where the fair value exceeded the carrying value by a less significant margin. The material assumptions used for the income approach for this reporting unit included a weighted average cost of capital of 15% and a long-term growth rate of 3%. This reporting unit had a goodwill balance of $17.2 million, and its fair value exceeded its carrying value by $1.0 million, or 3.5%. Under the income approach which is weighted 40%, a one percentage point increase in the discount rate and a one percentage point decrease in the long-term growth rate would have decreased the fair value of this reporting unit by $0.9 million. Under the public company market approach which has a weighting of 60%, a 10% decrease in the market approach multiples would have decreased the fair value of this reporting unit by $2.4 million.

        There are significant inherent uncertainties and management judgment involved in estimating the fair value of each reporting unit. While we believe we have made reasonable estimates and assumptions to estimate the fair value of our reporting units, it is possible that a material change could occur. If actual results are not consistent with our current estimates and assumptions, or the current economic downturn worsens or the projected recovery is significantly delayed beyond our projections, goodwill impairment charges may be recorded in future periods.

        We amortize identifiable intangible assets with finite lives over their useful lives. Intangible assets with indefinite lives are not amortized, but are subject to an annual review for impairment. Changes in strategy and/or market condition, may result in adjustments to recorded intangible asset balances or their useful lives.

Results of Operations (in thousands):

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2009 Compared to 2008

        Revenues decreased $192.9 million, or 14.6% to $1,128.9 million in 2009 compared to 2008. The revenue decrease stemmed primarily from reduced activity in the nonresidential markets throughout the United States especially in manufacturing (approximately $38.9 million), office buildings (approximately $38.6 million) as well as continued decreases in the multi-family sector (approximately $87.4 million). These decreases were partially offset by increased activity in the education (approximately $29.6 million) and government sectors (approximately $14.1 million).

        Backlog reflects revenues still to be recognized under contracted or committed installation and replacement project work. Project work generally lasts less than one year. Service agreement revenues and service work and short duration projects which are generally billed as performed do not flow through backlog. Accordingly, backlog represents only a portion of our revenues for any given future period, and it represents revenues that are likely to be reflected in our operating results over the next six to twelve months. As a result, we believe the predictive value of backlog information is limited to indications of general revenue direction over the near term, and should not be interpreted as indicative of ongoing revenue performance over several quarters.

        Backlog as of December 31, 2009 was $550.2 million (including $27.1 million from two companies acquired during the fourth quarter of 2009) a 0.7% decrease from September 30, 2009 backlog of $554.3 million. The sequential change in backlog was relatively flat due to an increase of approximately 4.9% related to acquisitions made during the fourth quarter of 2009. The internal decrease of 5.6% was primarily related to our Northern Maryland and Colorado operations. The internal decrease was offset by increases at our Central Arizona and Northern Virginia operations.

        Backlog as of December 31, 2009 was $550.2 million (including $27.1 million from two companies acquired during the fourth quarter of 2009), a 26.8% decrease from December 31, 2008 backlog of $751.6 million. Approximately 30.4% of the year-over-year decrease in backlog is primarily related to our Colorado and Arkansas operations as well as our planned downsizing of our large multi-family operation based in Texas. The internal decrease was offset by 3.6% increase related to acquisitions.

        Following the three-year period of industry activity declines from 2001-2003 noted previously, we saw modest year-over-year revenue increases at our ongoing operations beginning in mid-2003 and continuing throughout 2008. Based on our backlog and forecasts from industry construction analysts, we expect that activity levels in our industry are likely to decrease over the next twelve months, particularly in the area of new construction.

        We continue to experience a noticeable amount of price competition in our markets, which restrains our ability to increase revenues.

        Gross Profit—Gross profit decreased $34.4 million, or 13.2%, to $225.6 million in 2009 as compared to 2008. As a percentage of revenues, gross profit for 2009 was 20.0%, up slightly from 19.7% in 2008. The increase in gross profit percentage resulted primarily from improved profitability at our Northern Maryland (approximately $6.6 million), and Central Florida operation (approximately $3.7 million). These increases were partially offset by lower margins at our combined Arizona operations (approximately $3.9 million) and additional accruals for two completed projects associated with our multi-family operation based in Texas (approximately $3.0 million).

        Selling, General and Administrative Expenses ("SG&A")—SG&A decreased $11.8 million, or 6.5% for 2009 as compared to 2008. The decrease is primarily related to overhead reductions and lower compensation accruals due to lower profitability in 2009. As a percentage of revenues, SG&A increased from 13.7% in 2008 to 15.0% for 2009 due to a lower 2009 revenue base.

        Interest Income—Interest income decreased $2.0 million, or 77.0% in 2009. The decrease is primarily due to lower interest rates in 2009.

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        Income Tax Expense—Our year to date effective tax rate for 2009 was 38.3%, as compared to 38.3% in 2008. Adjustments to tax reserves are analyzed and adjusted quarterly as events occur to warrant such changes. Adjustments to tax reserves are a component of the effective tax rate. We currently estimate our effective tax rate for 2010 will be between 38% and 40%.

Discontinued Operations—

        We sold a small operating company in June 2009. This company's after tax loss of $0.1 million and $0.3 million for the year ended December 31, 2008 and 2009, respectively, has been recorded in discontinued operations under "Operating income (loss), net of tax benefit (expense)."

        We recorded an estimated loss on the sale of this company of $1.0 million in 2009. This loss has been reported in discontinued operations under "Estimated loss on disposition, net of income tax expense."

        In March 2002, we sold 19 operations to Emcor Group, Inc. ("Emcor"). There are ongoing obligations relating to this transaction that we continue to address with Emcor. We do not believe these obligations, either individually or in the aggregate, will have a material adverse effect on our financial position when ultimately resolved. During the fourth quarter of 2009, we recorded a gain of $0.8 million based upon a review of open matters. These amounts are reflected in discontinued operations in 2009 in the caption "Estimated loss on disposition, net of tax." We continue to evaluate the likely disposition of approximately $1.2 million that is currently held in escrow relating to this transaction.

2008 Compared to 2007

        Revenues increased $220.2 million, or 20.0% to $1,321.8 million in 2008 compared to 2007. Approximately 10.0% of the increase in revenues related to internal growth and the remaining 10.0% resulted from acquisitions. The internal revenue growth stemmed primarily from increased activity in the nonresidential markets throughout the United States especially in government (approximately $41.1 million), education (approximately $31.8 million) and healthcare facilities (approximately $27.1 million). These increases were partially offset by decreased activity in the multi-family sector (approximately $31.1 million). We have seen increased activity, primarily at our Central Florida, Central Arizona and Wisconsin operations, resulting from the start-up of several large projects partially offset by our planned downsizing of our large multi-family operations based in Texas and lower activity levels at our California operation.

        Backlog as of December 31, 2008 was $751.6 million a 6.5% decrease from September 30, 2008 backlog of $803.7 million. The sequential decrease was primarily due to the planned decrease at our large multi-family operation based in Texas, as well as decreases at our Virginia, Tennessee, and Central Arizona operations. On a same store basis, backlog as of December 31, 2008 was $659.6 million, a decrease of 16.0% from December 31, 2007 backlog of $785.0 million. The year-over-year decrease is primarily due to planned decrease at our large multi-family operation based in Texas, as well as decreases at our Central Arizona and Central Florida locations.

        Gross Profit—Gross profit increased $64.7 million, or 33.1%, to $259.9 million in 2008 as compared to 2007. Approximately 23.5% of the increase is due to internal growth and the remaining 9.6% is due to acquisitions. As a percentage of revenues, gross profit for 2008 was 19.7%, up from 17.7% in 2007. The increase in gross profit percentage resulted primarily from improved results at our large multi-family operation based in Texas (approximately $13.4 million), as well as from improved profitability at our Central Florida operation (approximately $5.3 million), and at our Southern Maryland operation (approximately $3.6 million). These increases were partially offset by lower margins at our combined Arizona operations (approximately $2.0 million) and Central Washington operation (approximately $2.3 million).

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        Selling, General and Administrative Expenses ("SG&A")—SG&A increased $35.0 million, or 24.0% for 2008 as compared to 2007. As a percentage of revenues, SG&A increased from 13.2% in 2007 to 13.7% for 2008. This is primarily due to higher compensation accruals due to strong performance at a number of our operations, an increase in the number of selling and overhead personnel for new or expanded service operations, the acquisition and start-up of new operations and increased bad debt expense.

        Interest Income—Interest income decreased $0.7 million, or 22.6% in 2008. The decrease is primarily due to lower interest rates in 2008.

        Interest Expense—Interest expense increased $0.8 million, or 125.0%. The increase is primarily due to the interest expense associated with notes due to former owners of companies acquired in 2008.

        Income Tax Expense—Our year to date effective tax rate for 2008 was 38.3%, as compared to 38.2% in 2007. Adjustments to tax reserves are analyzed and adjusted quarterly as events occur to warrant such changes. Adjustments to tax reserves are a component of the effective tax rate.

Discontinued Operations

        We sold a small operating company in June 2009. This company's after tax income of $0.2 million for the year ended December 31, 2007 and after tax loss of $0.1 million for the year ended December 31, 2008, have been recorded in discontinued operations under "Operating income (loss), net of tax benefit (expense)."

Outlook

        We expect that developing weakness in the underlying environment for nonresidential activity has and will continue to affect 2010 activity levels in our industry compared to recent years. Our backlog while still at solid levels by historical standards has been declining. Our primary emphasis for 2010 will be on execution including a focus on cost controls and efficient project and service performance at the unit level. Based on our backlog and the weakening economic conditions for our industry, we expect continued profitability during 2010, but we expect lower profitability than we achieved in 2009 as industry conditions continue to weaken.

Liquidity and Capital Resources

        Cash Flow—We define free cash flow as cash provided by operating activities, less customary capital expenditures, plus the proceeds from asset sales. Positive free cash flow represents funds available to invest in significant operating initiatives, to acquire other companies, or to reduce a company's outstanding debt or equity. If free cash flow is negative, additional debt or equity is

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generally required to fund the outflow of cash. Free cash flow may be defined differently by other companies.

        Our business does not require significant amounts of investment in long-term fixed assets. The substantial majority of the capital used in our business is working capital that funds our costs of labor and installed equipment deployed in project work until our customers pay us. Customary terms in our industry allow customers to withhold a small portion of the contract price until after we have completed the work, typically for six months. Amounts withheld under this practice are known as retention or retainage. Our average project duration together with typical retention terms generally allow us to complete the realization of revenue and earnings in cash within one year. Accordingly, we believe free cash flow, by encompassing both profit margins and the use of working capital over our approximately one year working capital cycle, is an effective measure of operating effectiveness and efficiency. We have included free cash flow information here for this reason, and because we are often asked about it by third parties evaluating us. However, free cash flow is not considered under generally accepted accounting principles to be a primary measure of an entity's financial results, and accordingly free cash flow should not be considered an alternative to operating income, net income, or amounts shown in our consolidated statements of cash flows as determined under generally accepted accounting principles.

        For the year ended December 31, 2009, we had free cash flow of $45.6 million as compared to $68.9 million in 2008. This decrease is primarily due to lower income in 2009 as our net income decreased by $15.5 million, from $49.7 million in 2008 to $34.2 million in 2009. For the year ended December 31, 2008, we had free cash flow of $68.9 million as compared to $72.8 million in 2007. This decrease resulted primarily from an investment in working capital due to higher activity levels.

        As of December 31, 2009, our marketable securities consisted of $5.6 million of auction rate securities, which are variable rate debt instruments, having long-term maturities, but whose interest rates are designed to reset through an auction process, at intervals ranging from seven to 35 days. We had $9.4 million investments in marketable securities as of December 31, 2008. All of our auction rate securities are high quality direct municipal obligations which have high investment grade ratings or otherwise are backed by high investment grade rated insurance agencies. In February 2008, liquidity issues in the global credit markets caused auctions representing some of the auction rate securities we hold to fail because the amount of securities offered for sale exceeded the bids. As a result, the liquidity of our remaining auction rate securities has diminished, and we expect that this decreased liquidity for our auction rate securities will continue as long as the present depressed global credit market environment persists, or until issuers refinance and replace these securities with other instruments. As a result of the temporary declines in fair value for our auction rate securities, which we attribute to liquidity issues rather than credit issues, we recorded an unrealized loss of $0.3 million, net of tax of $0.1 million, to accumulated other comprehensive income (loss). Our analysis of the fair values of these securities considered, among other items, the creditworthiness of the counterparty, the timing of expected future cash flows, and the possibility that a discount may be required if we choose to sell the securities in the absence of a successful auction. These securities were also compared, when possible, to other observable market data with similar characteristics.

        As a result of the current situation in the auction markets, our ability to liquidate our investment in auction rate securities and fully recover the carrying value of our investment in the near term may be limited or impossible. If in the future the issuers are unable to successfully close future auctions and their credit ratings deteriorate and if we determine that any future valuation adjustment was other than temporary, we may be required to record an impairment charge on these investments. Because the tax exempt interest rates on these bonds are relatively attractive, we believe that we may be able to liquidate our investment without significant loss in the foreseeable future; however, it could take until the final maturity of the underlying notes (up to October 2034) to be repaid. Based on our expected operating cash flows, and our other sources of cash, we do not anticipate the potential lack of liquidity

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on these investments will affect our ability to execute our current business plan. For the years ended December 31, 2008 and 2009, we sold $8.6 million and $4.0 million, respectively, of these auction rate securities at face value. An additional $0.9 million was sold at face value during February 2010; this is included in "Prepaid Expenses and Other" in our consolidated balance sheet.

        As of March 29, 2007, our Board of Directors (the "Board") approved a stock repurchase program to acquire up to one million shares of our outstanding stock. As of December 31, 2008, the Board approved extensions of the program to cover an additional 2.9 million shares. During the first quarter of 2009, the Board approved an extension of the program to cover an additional 0.5 million shares. During the third quarter of 2009, the Board approved an extension of the program to cover an additional 0.5 million shares. Since the inception of the repurchase program, the Board has approved 4.9 million shares to be repurchased.

        The share repurchases will be made from time to time at our discretion in the open market or privately negotiated transactions as permitted by securities laws and other legal requirements, and subject to market conditions and other factors. The Board may modify, suspend, extend or terminate the program at any time. We repurchased 1.2 million shares for approximately $12.6 for year ended December 31, 2009, at an average price of $10.39 per share. We repurchased 0.9 million shares for approximately $11.1 million and 2.4 million shares for approximately $25.5 million under our share repurchase program for the years ended December 31, 2007 and 2008, respectively. Since the inception of the repurchase program in 2007, we have repurchased a cumulative total of 4.4 million shares as of December 31, 2009, for $49.2 million, at an average price of $11.15 per share.

        Credit Facility—On February 20, 2007, we entered into a $100.0 million senior credit facility (the "Facility") provided by a syndicate of banks. The Facility expires in February 2012 and is secured by the capital stock of our current and future subsidiaries. As of December 31, 2009, we had no outstanding borrowings, $39.1 million in letters of credit outstanding, and $60.9 million of credit available.

        In conjunction with our December 31, 2009 acquisition of a company based in Raleigh, North Carolina, we acquired $0.3 million of short-term borrowings. This is included as current debt on our balance sheet as of December 31, 2009.

        We have a choice of two interest rate options for borrowings under the Facility; these rates are floating rates determined by the broad financial markets, meaning they can and do move up and down from time to time. Excluding the amortization of debt financing and arrangement cost, we estimate that the interest rate applicable to the borrowings under the Facility would be approximately 1.5% as of December 31, 2009. Commitment fees are payable on the portion of the capacity not in use for borrowings or letters of credit at any given time. These fees range from 0.20%-0.30% per annum, based on the ratio of debt to Credit Facility Adjusted EBITDA.

        Interest expense included the following primary elements (in thousands):

        Covenant compliance is assessed as of each quarter end. We were in compliance with all of the financial covenants as of December 31, 2009. Credit Facility Adjusted EBITDA is defined under the Facility for financial covenant purposes as net earnings for the four quarters ending as of any given

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quarterly covenant compliance measurement date, plus the corresponding amounts for (a) interest expense; (b) income taxes; (c) depreciation and amortization; and (d) other non-cash charges. The following is a reconciliation of Credit Facility Adjusted EBITDA to net income (in thousands):

        The Facility contains financial covenants defining various measures and the levels of these measures with which we must comply. The Facility's principal financial covenants include:

        Leverage Ratio— The Facility requires that the ratio of our total indebtedness less cash and cash equivalents to our Credit Facility Adjusted EBITDA not exceed 2.50. The leverage ratio as of December 31, 2009 was 0.11.

        Fixed Charge Coverage Ratio— The Facility requires that the ratio of Credit Facility Adjusted EBITDA, less non-financed capital expenditures, tax provision, dividends and amounts used to repurchase stock to the sum of interest expense and scheduled principal payments be at least 1.50. Capital expenditures, tax provision, dividends and stock repurchase payments are defined under the Facility for purposes of this covenant to be amounts for the four quarters ending as of any given quarterly covenant compliance measurement date. The calculation of the fixed charge coverage ratio excludes acquisitions, stock repurchases and the payment of cash dividends at any time that the Leverage Ratio does not exceed 1.0. The fixed charge coverage ratio as of December 31, 2009 was 17.52.

        Other Restrictions— The Facility permits acquisitions of up to $25.0 million per transaction, or $50.0 million in the aggregate. However, these limitations only apply when the Leverage Ratio is greater than 1.0.

        While the Facility's financial covenants do not specifically govern capacity under the Facility, if our debt level under the Facility at a quarter-end covenant compliance measurement date were to cause us to violate the Facility's debt-to-Credit Facility Adjusted EBITDA covenant, our borrowing capacity under the Facility and the favorable terms that we currently enjoy could be negatively impacted by the lenders.

        Notes to Former Owners—We issued subordinated notes to the former owners of acquired companies, as part of the consideration used to acquire these companies. These notes had an outstanding balance of $7.4 million, of which $0.9 million is current, as of December 31, 2009 and bear interest, payable annually, at a weighted average interest rate of 4.9%.

        Off-Balance Sheet Arrangements and Other Commitments—As is common in our industry, we have entered into certain off-balance sheet arrangements in the ordinary course of business that result in risks not directly reflected in our balance sheets. Our most significant off-balance sheet transactions include liabilities associated with noncancelable operating leases. We also have other off-balance sheet obligations involving letters of credit and surety guarantees.

        We enter into noncancelable operating leases for many of our facility, vehicle and equipment needs. These leases allow us to conserve cash by paying a monthly lease rental fee for use of facilities, vehicles and equipment rather than purchasing them. At the end of the lease, we have no further

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obligation to the lessor. If we decide to cancel or terminate a lease before the end of its term, we would typically owe the lessor the remaining lease payments under the term of the lease.

        Certain of our vendors require letters of credit to ensure reimbursement for amounts they are disbursing on our behalf, such as to beneficiaries under our self-funded insurance programs. We have also occasionally used letters of credit to guarantee performance under our contracts and to ensure payment to our subcontractors and vendors under those contracts. The letters of credit we provide are actually issued by our lenders through the Facility as described above. A letter of credit commits the lenders to pay specified amounts to the holder of the letter of credit if the holder demonstrates that we have failed to perform specified actions. If this were to occur, we would be required to reimburse the lenders. Depending on the circumstances of such a reimbursement, we may also have to record a charge to earnings for the reimbursement. Absent a claim, there is no payment or reserving of funds by us in connection with a letter of credit. However, because a claim on a letter of credit would require immediate reimbursement by us to our lenders, letters of credit are treated as a use of the Facility's capacity just the same as actual borrowings. Claims against letters of credit are rare in our industry. To date we have not had a claim made against a letter of credit that resulted in payments by a lender or by us. We believe that it is unlikely that we will have to fund claims under a letter of credit in the foreseeable future.

        Many customers, particularly in connection with new construction, require us to post performance and payment bonds issued by a financial institution known as a surety. If we fail to perform under the terms of a contract or to pay subcontractors and vendors who provided goods or services under a contract, the customer may demand that the surety make payments or provide services under the bond. We must reimburse the sureties for any expenses or outlays they incur. To date, we are not aware of any losses to our sureties in connection with bonds the sureties have posted on our behalf, and we do not expect such losses to be incurred in the foreseeable future.

        Surety market conditions are currently challenging as a result of significant losses incurred by many sureties in recent periods, both in the construction industry as well as in certain larger corporate bankruptcies. As a result, less bonding capacity is available in the market and terms have become more restrictive. Further, under standard terms in the surety market, sureties issue bonds on a project-by-project basis, and can decline to issue bonds at any time. Historically, approximately 25% to 30% of our business has required bonds. While we have enjoyed strong surety relationships to support our bonding needs, current market conditions as well as changes in our sureties' assessment of our operating and financial risk could cause our sureties to decline to issue bonds for our work. If that were to occur, our alternatives include doing more business that does not require bonds, posting other forms of collateral for project performance such as letters of credit or cash, and seeking bonding capacity from other sureties. We would likely also encounter concerns from customers, suppliers and other market participants as to our creditworthiness. While we believe our general operating and financial characteristics, including a significant amount of cash on our balance sheet, would enable us to ultimately respond effectively to an interruption in the availability of bonding capacity, such an interruption would likely cause our revenues and profits to decline in the near term.

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        The following recaps the future maturities of our contractual obligations as of December 31, 2009 (in thousands):

        Absent any significant commitments of capital for items such as capital expenditures, acquisitions, dividends and share repurchases, it is reasonable to expect us to continue to maintain excess cash on our balance sheet. Therefore, we assumed that we would continue our current status of not utilizing any borrowings under our revolving loan.

        As of December 31, 2009, we also have $39.1 million letter of credit commitments, of which $38.6 million expire in 2010 and $0.5 million expire in 2011. The substantial majority of these letters of credit are posted with insurers who disburse funds on our behalf in connection with our worker's compensation, auto liability and general liability insurance program. These letters of credit provide additional security to the insurers that sufficient financial resources will be available to fund claims on our behalf, many of which develop over long periods of time, should we ever encounter financial duress. Posting of letters of credit for this purpose is a common practice for entities that manage their self-insurance programs through third-party insurers as we do. While most of these letter of credit commitments expire in 2010, we expect nearly all of them, particularly those supporting our insurance programs, will be renewed annually.

        Other than the operating lease obligations noted above, we have no significant purchase or operating commitments outside of commitments to deliver equipment and provide labor in the ordinary course of performing project work.

        Outlook—We have generated positive net free cash flow for the last ten calendar years, much of which occurred during challenging economic and industry conditions. We also expect to have borrowing capacity under our credit facility and we continue to have uncommitted cash balances. We believe these factors will provide us with sufficient liquidity to fund our operations for the foreseeable future.

Recent Accounting Pronouncements

        On September 30, 2009, we adopted changes issued by the Financial Accounting Standards Board ("FASB") to the authoritative hierarchy of generally accepted accounting principles ("GAAP"). These changes establish the FASB Accounting Standards Codification^TM ("Codification") as the source of authoritative accounting principles recognized by the FASB to be applied by nongovernmental entities in the preparation of financial statements in conformity with GAAP. Rules and interpretive releases of the SEC under authority of federal securities laws are also sources of authoritative GAAP for SEC registrants. These changes and the Codification itself do not change GAAP. Other than the manner in which new accounting guidance is referenced, the adoption of these changes had no impact on the consolidated financial statements.

Fair Value Accounting

        On January 1, 2009, we adopted changes issued by the FASB to fair value accounting and reporting as it relates to nonfinancial assets and nonfinancial liabilities that are not recognized or disclosed at fair value in the financial statements on at least an annual basis. These changes define fair

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value, establish a framework for measuring fair value in GAAP, and expand disclosures about fair value measurements. This guidance applies to other GAAP that require or permit fair value measurements and is to be applied prospectively with limited exceptions. The adoption of these changes, as it relates to nonfinancial assets and nonfinancial liabilities, had no impact on the consolidated financial statements, however we have expanded the disclosures regarding marketable securities, goodwill, and intangible assets.

Business Combinations and Consolidation Accounting

        On January 1, 2009, we adopted changes issued by the FASB to accounting for business combinations. These changes apply to all assets acquired and liabilities assumed in a business combination that arise from certain contingencies and requires (i) an acquirer to recognize at fair value, at the acquisition date, an asset acquired or liability assumed in a business combination that arises from a contingency if the acquisition-date fair value of that asset or liability can be determined during the measurement period otherwise the asset or liability should be recognized at the acquisition date if certain defined criteria are met; (ii) contingent consideration arrangements of an acquiree assumed by the acquirer in a business combination be recognized initially at fair value; (iii) subsequent measurements of assets and liabilities arising from contingencies be based on a systematic and rational method depending on their nature and contingent consideration arrangements be measured subsequently; and (iv) disclosures of the amounts and measurement basis of such assets and liabilities and the nature of the contingencies. The adoption will significantly impact our accounting and reporting for acquisitions, principally (i) as a result of the expanded requirements to value acquired assets, liabilities and contingencies at their fair values and (ii) the requirement that acquisition related transaction costs be expensed as incurred rather than capitalized as a part of the cost of the acquisition.

Earnings Per Share

        On January 1, 2009, we adopted changes issued by the FASB to the calculation of earnings per share. These changes state that unvested share-based payment awards that contain nonforfeitable rights to dividends or dividend equivalents (whether paid or unpaid) are participating securities and shall be included in the computation of earnings per share pursuant to the two-class method for all periods presented. There was no significant impact upon the adoption of these changes.

Subsequent Events

        On June 30, 2009, we adopted changes issued by the FASB to accounting for and disclosure of events that occur after the balance sheet date but before financial statements are issued. This change had no impact on our consolidated financial statements.

ITEM 7A.    Quantitative and Qualitative Disclosures about Market Risk

        We are exposed to market risk primarily related to potential adverse changes in interest rates as discussed below. We are actively involved in monitoring exposure to market risk and continue to develop and utilize appropriate risk management techniques. We are not exposed to any other significant financial market risks including commodity price risk, foreign currency exchange risk or interest rate risks from the use of derivative financial instruments. We do not use derivative financial instruments.

        We have limited exposure to changes in interest rates under our revolving credit facility. We have a debt facility under which we may borrow funds in the future. We do not currently foresee any borrowing needs. Our debt with fixed interest rates consists of notes to former owners of acquired companies.

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        The following table presents principal amounts (stated in thousands) and related average interest rates by year of maturity for our debt obligations and their indicated fair market value at December 31, 2009:

        As of December 31, 2009, our marketable securities consisted of $5.6 million of auction rate securities, which are variable rate debt instruments, having long-term maturities, but whose interest rates are designed to reset through an auction process, at intervals ranging from seven to 35 days. We had $9.4 million in investments of marketable securities as of December 31, 2008. All of our auction rate securities are high quality direct municipal obligations which have high investment grade ratings or otherwise are backed by high investment grade rated insurance agencies. In February 2008, liquidity issues in the global credit markets caused auctions representing some of the auction rate securities we hold to fail because the amount of securities offered for sale exceeded the bids. As a result, the liquidity of our remaining auction rate securities has diminished, and we expect that this decreased liquidity for our auction rate securities will continue as long as the present depressed global credit market environment persists, or until issuers refinance and replace these securities with other instruments. As a result of the temporary declines in fair value for our auction rate securities, which we attribute to liquidity issues rather than credit issues, we recorded an unrealized loss of $0.3 million, (net of tax of less than $0.1 million) to accumulated other comprehensive income (loss). Our analysis of the fair values of these securities considered, among other items, the creditworthiness of the counterparty, the timing of expected future cash flows, and the possibility that a discount may be required if we choose to sell the securities in the absence of a successful auction. These securities were also compared, when possible, to other observable market data with similar characteristics.

        As a result of the current situation in the auction markets, our ability to liquidate our investment in auction rate securities and fully recover the carrying value of our investment in the near term may be limited or impossible. If in the future the issuers are unable to successfully close future auctions and their credit ratings deteriorate and if we determine that any future valuation adjustment was other than temporary, we may be required to record an impairment charge on these investments. Because the tax exempt interest rates on these bonds are relatively attractive, we believe that we may be able to liquidate our investment without significant loss in the foreseeable future; however, it could take until the final maturity of the underlying notes (up to October 2034) to be repaid. Based on our expected operating cash flows, and our other sources of cash, we do not anticipate the potential lack of liquidity on these investments will affect our ability to execute our current business plan.

        We measure certain assets, including our goodwill and intangible assets at a fair value on a nonrecurring basis. These assets are recognized at fair value when they are deemed to be other-than-temporarily impaired. For the year ended December 31, 2009, we recognized an impairment expense of $0.2 million related to an indefinite-lived tradename of a subsidiary.

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ITEM 8.    Financial Statements and Supplemental Data

INDEX TO FINANCIAL STATEMENTS

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Management's Report on Internal Control over Financial Reporting

        Our management is responsible for establishing and maintaining adequate internal control over financial reporting, as such term is defined in Exchange Act Rules 13a-15(f) and 15d-15(f). Under the supervision and with the participation of our management, including our Chief Executive Officer and Chief Financial Officer, we conducted an evaluation of the effectiveness of our internal control over financial reporting as of December 31, 2009 based on the framework in Internal Control—Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO). Based on that evaluation, our management concluded that our internal control over financial reporting was effective as of December 31, 2009.

        Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

        Ernst & Young LLP, an independent registered public accounting firm, as stated in their report which is included elsewhere herein, has issued an attestation report auditing the effectiveness of our internal control over financial reporting as of December 31, 2009.

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REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

The Board of Directors and Stockholders of Comfort Systems USA, Inc.

        We have audited the accompanying consolidated balance sheets of Comfort Systems USA, Inc. as of December 31, 2009 and 2008, and the related consolidated statements of operations, stockholders' equity, and cash flows for each of the three years in the period ended December 31, 2009. These financial statements are the responsibility of the Company's management. Our responsibility is to express an opinion on these financial statements based on our audits.

        We conducted our audits in accordance with the standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement. An audit includes examining, on a test basis, evidence supporting the amounts and disclosures in the financial statements. An audit also includes assessing the accounting principles used and significant estimates made by management, as well as evaluating the overall financial statement presentation. We believe that our audits provide a reasonable basis for our opinion.

        In our opinion, the financial statements referred to above present fairly, in all material respects, the consolidated financial position of Comfort Systems USA, Inc. at December 31, 2009 and 2008, and the consolidated results of its operations and its cash flows for each of the three years in the period ended December 31, 2009, in conformity with U.S. generally accepted accounting principles.

        We also have audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States), Comfort Systems USA, Inc.'s internal control over financial reporting as of December 31, 2009, based on criteria established in Internal Control-Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission and our report dated March 1, 2010 expressed an unqualified opinion thereon.

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REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

The Board of Directors and Stockholders of Comfort Systems USA, Inc.

        We have audited Comfort Systems USA, Inc.'s internal control over financial reporting as of December 31, 2009, based on criteria established in Internal Control—Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission (the COSO criteria). Comfort Systems USA, Inc.'s management is responsible for maintaining effective internal control over financial reporting, and for its assessment of the effectiveness of internal control over financial reporting included in the accompanying Management's Report on Internal Control over Financial Reporting. Our responsibility is to express an opinion on the company's internal control over financial reporting based on our audit.

        We conducted our audit in accordance with the standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audit to obtain reasonable assurance about whether effective internal control over financial reporting was maintained in all material respects. Our audit included obtaining an understanding of internal control over financial reporting, assessing the risk that a material weakness exists, testing and evaluating the design and operating effectiveness of internal control based on the assessed risk, and performing such other procedures as we considered necessary in the circumstances. We believe that our audit provides a reasonable basis for our opinion.

        A company's internal control over financial reporting is a process designed to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles. A company's internal control over financial reporting includes those policies and procedures that (1) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions of the assets of the company; (2) provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that receipts and expenditures of the company are being made only in accordance with authorizations of management and directors of the company; and (3) provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use, or disposition of the company's assets that could have a material effect on the financial statements.

        Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

        In our opinion, Comfort Systems USA, Inc. maintained, in all material respects, effective internal control over financial reporting as of December 31, 2009, based on the COSO criteria.

        We also have audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States), the consolidated balance sheets as of December 31, 2009 and 2008 and the related consolidated statements of operations, stockholders' equity, and cash flows for each of the three years in the period ended December 31, 2009 of Comfort Systems USA, Inc. and our report dated March 1, 2010 expressed an unqualified opinion thereon.

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COMFORT SYSTEMS USA, INC.

CONSOLIDATED BALANCE SHEETS

(In Thousands, Except Share Amounts)

The accompanying notes are an integral part of these consolidated financial statements.

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COMFORT SYSTEMS USA, INC.

CONSOLIDATED STATEMENTS OF OPERATIONS

(In Thousands, Except Per Share Data)