MSI Mechanical Systems Inc. is a Salem, New Hampshire based full service mechanical contractor and facilities service provider for your Commercial, Industrial & Retail projects. From the basic, to the most sophisticated of mechanical systems, MSI has engineered and built them. In fact, since our founding in 1995, we have installed almost every type of HVAC & Process Piping system in the industry. Choosing a mechanical contractor should not be predicated on the lowest price, but rather on a combination of price and these four most important factors: sensible design, quality installation, project performance, and service after the installation. We know what it takes to successfully build and service your mechanical systems. Since 1995 we've been doing just that throughout New Hampshire and Massachusetts.