Est. 1929
Berkeley’s Original. A New Chapter.
John Toivonen started Aarvaks in 1929, installing heating systems across Berkeley when the city was rebuilding after the Hills fire. Under new ownership since 2025, the company is still independent, still local, and operating at the highest level it ever has.
Founded in Berkeley
Years Serving the East Bay
Family-Owned
Est. 1929
Aarvaks — A Berkeley Original.
The story of Aarvaks started with John Toivonen, a recent immigrant to Berkeley from Finland. During the building boom that followed the 1923 Berkeley Hills fire, John saw an opportunity to install the latest heating systems in residential homes. He specialized in replacing old, coal-burning systems with natural gas, a cleaner, more comfortable way to heat a home.
Just starting out, his business was not immune to the Great Depression and John worked hard to sell his services. A good natured fellow with a sense of humor, one of his favorite things to do was to walk on his hands from door to door, even up porch steps to ask for business saying aarvaks, a Finnish slang word for “guess who?”.
New Ownership
Jason Hanson, Owner
Jason Hanson acquired Aarvaks in November 2025. He spent the past 15 years at Hassler Heating and Air Conditioning, one of the most respected HVAC operations in the East Bay, where he played a central role in building the company into what it became.
When Jason took over Aarvaks, he brought many of Hassler’s top technicians and service staff with him — a team with deep technical knowledge across heating, cooling, heat pumps, and mini-splits. This is the most experienced crew Aarvaks has had in its 97-year history.
Our Approach
How We Work.
One Stop Shop
From service and repair to full system design and installation — heating, cooling, and indoor air quality under one roof.
Built for Efficiency
We install the highest-efficiency equipment available and help East Bay homeowners access every rebate they qualify for.
Environmental Responsibility
We recycle metal, refrigerant, and job site materials. Some of our service trucks run on recycled vegetable oil.
Credentials
Licensed, Certified, Accredited.
Berkeley’s Most Trusted HVAC Company. Since 1929.
Four generations of East Bay families have trusted Aarvaks to keep their homes comfortable.