Zettler Controls Inc. is a US-based renowned HVACR component manufacturer with an extensive offering of relays, thermostats, transformers, heat sequencers, temperature sensors, and fan centers.

Zimmer's Heating & Cooling business has expanded to include residential, retail, and commercial heating and cooling.

ZONEFIRST is the first company that successfully developed and marketed HVAC Zoning Systems back in the 1950's and is today a renowned manufacturer of HVAC zone dampers and zoning systems. They provide zone control systems, automatic dampers, registers and diffusers for fresh air intake, economizers and ventilation control.