Coziahr Heating & Air Conditioning, 1409 Third Ave., offers sales, installation and service of heating and air conditioning systems and components, as well as home energy assessments and radon testing. And they do it all with two employees: owner Dave Coziahr and his wife, Luanne. Luanne goes with me on all my runs. We're a team. Many customers begin their relationship with the business when they need a new system. Saving energy on heating and cooling is more complicated than it sounds, Coziahr said.