As a specifying engineer, I have had the privilege of working with GW Mechanical for almost 20 years.  Over that time I have been consistently impressed with the competence of their workforce, their quality of workmanship and attention to detail, and their steadfast commitment to our projects and the building owners, well after construction is complete.  Qualities such as these are increasingly rare; I would endorse GW Mechanical for any commercial project.
Jak Peden Hollinger P.E.