| Employer | City | |
| Advanced Heating & Cooling LLC. | Reisterstown | View Profile |
| Alternative Energy Resources | Various Locations | View Profile |
| American Mechanical Services | Laurel | View Profile |
| Brumwells One Hour Inc. | Pasadena | View Profile |
| Construct Corps | Various Locations | View Profile |
| Crockett Facilities Services, Inc. | Bowie | View Profile |
| Direct Energy - US Home Services | Various Locations | View Profile |
| Don Hoffacker's Air Conditioning & Heating, Inc. | Germantown | View Profile |
| Eaton Services, Inc. | Beltsville | View Profile |
| Electric Motor Repair Company | Rosedale | View Profile |
| Emcor Group | Various Locations | View Profile |
| EMS Technologies | Crofton | View Profile |
| Fidelity Engineering Corp. | Sparks | View Profile |
| First Service Networks | Linthicum | View Profile |
| Four Seasons Environmental, Inc. | Various Locations | View Profile |
| GMH Communities | Various Locations | View Profile |
| HBE Corporation | Various Locations | View Profile |
| Honeywell | Various Locations | View Profile |
| Ingersoll Rand Climate Control Technologies | Various Locations | View Profile |
| James Vito, Inc. | Rockville | View Profile |
| Johnson Controls Inc, Building Efficiency | Various Locations | View Profile |
| KBR | Various Locations | View Profile |
| L H Cranston & Sons Inc. | Hunt Valley | View Profile |
| Manpower | Various Locations | View Profile |
| Maritime Institute of Technology & Graduate Studies | Linthicum Heights | View Profile |
| McQuay International/McQuay Service | Various Locations | View Profile |
| MEP Jobs - Customer Fulfillment | Various Locations | View Profile |
| Minnicks, Inc. | Laurel | View Profile |
| Moon Services Inc. | Elkton | View Profile |
| NES Rentals Holdings, Inc | Various Locations | View Profile |
| Nexant, Inc | Various Locations | View Profile |
| NORESCO | Various Locations | View Profile |
| Quality Refrigeration Services | Baltimore | View Profile |
| Quick Servant Co., Inc. | Elkridge | View Profile |
| Service Logic | Various Locations | View Profile |
| Shapiro & Duncan, Inc. | Rockville | View Profile |
| Shawmut Design and Construction | Various Locations | View Profile |
| Siemens Building Technologies | Various Locations | View Profile |
| Siemens Building Technologies, Inc. | Various Locations | View Profile |
| Taylor Equipment Distributors | Hyattsville | View Profile |
| The Linc Group | Various Locations | View Profile |
| Trane Commercial Systems | Various Locations | View Profile |
| Transwestern | Various Locations | View Profile |
| Tri-County Plumbing & Heating | Rocky Ridge | View Profile |
| URS Corporation | Various Locations | View Profile |
| W.E. Welch & Associates, Inc. | Ijamsville | View Profile |