[Commercial HVAC Ann Arbor | Altech Mechanical Service | Commercial HVAC, Industrial HVAC Altech Mechanical Service Heating, Air Conditioning, and Refrigeration Since 1997. CUSTOM COMMERCIAL & INDUSTRIAL SOLUTIONS Let our decades of experience help you realize your commercial project’s goals. Quality Our installations and service calls are completed with the highest quality materials. We believe in the integrity of our work, and getting the job done correctly the first time.]