Commercial or residential HVAC services, Total Mechanical Systems has you covered. Centrally located on Long Island, Total Mechanical Systems has been serving Nassau and Suffolk since 1981. Computerized dispatching and continuous technician training is what makes Total Mechanical the ELITE Team – the Entire Long Island Temperature Experts! Originally known as Mechanical System Services, the company earned its stripes in the HVAC/R industry through hard work, dedication, and a strong belief in providing honest and affordable service.