An HVAC system having an air cleaner, a fan configured to selectively generate an air flow, wherein at least a portion of the air flow is passed through the air cleaner, and a controller configured to control the air cleaner in response to at least one of a setting for controlling the fan and an operation characteristic of the fan is disclosed. A method of controlling an air cleaner by determining an air flow related criterion value, wherein the air flow is associated with an air flow through an air cleaner, comparing the determined air flow related criterion value to a threshold criterion value, and controlling the air cleaner as a function of a result of comparing the determined air flow related criterion value to the threshold criterion value is disclosed. A method of controlling an ozone concentration outputted by an air cleaner is disclosed.