| Business | Phone |
| Webber's Heating & Air Cond 27404 Ridge Rd, Damascus 20872 | (301) 253-3557 |
| Switzerland Air Heat & Cooling Po Box 67, Damascus 20872 | (301) 607-9877 |
| Sunn Corp Po Box 187, Damascus 20872 | (301) 384-4909 |
| Delta Thvac 24300 Ridge Rd, Damascus 20872 | (301) 253-0966 |
| Montgomery Air Conditioning Damascus 20872 | (301) 482-1190 |
| Hamilton Conard Heating 11247 Bethesda Church Rd, Damascus 20872 | (301) 482-0515 |