The people behind the content

Marcus Tillman spent 14 years as a commercial HVAC technician in the Dallas-Fort Worth area before transitioning into workforce training after a field injury. He holds EPA 608 Universal certification, NATE certification in Air Conditioning and Heat Pumps, and the HVAC Excellence Master Technician credential. At HVACJobs.IO, Marcus writes about the career and certification decisions that actually affect a technician's paycheck — from which state has the best market conditions to whether the NATE exam is worth the study time. His advice comes from the field, not from a trade publication.

Diane Kowalski spent more than a decade managing hiring and workforce operations for HVAC and mechanical contractors in the Chicago area. As HR Director for a 90-person residential and light-commercial company, she ran hundreds of technician searches, built apprenticeship pipelines with local JATC programs, and implemented field service management platforms across a mixed fleet of residential and commercial crews. She holds the SHRM-CP certification and now consults independently on workforce strategy for skilled-trades businesses. At HVACJobs.IO, she writes for contractors who are tired of posting on generalist boards and wondering why their phones aren't ringing.

Rob Castillo spent eight years as a residential HVAC service technician in Phoenix and Tucson, working on heat pumps, mini-splits, and gas furnaces in one of the most demanding cooling climates in the country. He holds EPA 608 Universal certification. After a back injury ended his time in the field, he moved into consumer home improvement writing, translating technical HVAC knowledge into advice that homeowners can actually use — including what a technician is looking at when they diagnose a problem, what repairs actually cost, and when a second opinion is worth the call. At HVACJobs.IO, Rob writes the homeowner content: straightforward guides that help you troubleshoot what you can, understand what you can't, and avoid getting overcharged for either.