| Business | Phone |
| Dry Air Systems Inc 36 Boyd Rd, Londonderry 3053 | (603) 425-7700 |
| Homans Associates 10 Liberty Dr, Londonderry 3053 | (603) 437-0033 |
| New England Mechanical Assoc 23 Londonderry Rd # 14, Londonderry 3053 | (603) 421-0505 |
| Tempered Water & Air Systems Londonderry 3053 | (603) 434-5300 |