Most furnaces underpeform due to poor installation. Steven Deesho, lead installer, and Nicholas Pacheco did a FIRST RATE job - FIVE STARS. EXTREMELY clean and efficient install, including de-install of old unit, and re-run of all piping due to yet another ridiculous code change. (Sorry, but these codes all seem so frivolous and wasteful to me. And, yes, I understand the physics.) Very respectful of my environment, taking great pains to make sure nothing was impacted by their work. Five hours, start to finish, with cleanup. Top notch.