We've Grown. We Are Now... Therma is one of the largest design-build mechanical service providers in the country and a leading provider of mission critical services in the Bay Area. The acquisition of Integrated Mechanical Systems expands our geographic footprint in Southern California. Therma Headquarters: 1601 Las Plumas Ave, San Jose, CA 95133 866-300-3611 Employee Links © 2021 Therma. All rights reserved. Privacy Policy Website Built By Brantley Agency.