Linearization
What is this all about?
Linearization
Linearization is a proprietary algorithm that maps the damper position to various airflow volumes. In a nut shell, depending on the damper type and size, the damper position in percentage is rarely equal to the percentage of airflow desired. Having multiple dampers on a zone complicates the non-linear damper/airflow further, but linearization compensates for that.
For instance in a round damper, opening the damper 20% will result in less than 20% of the airflow one might expect. A square or rectangle damper, with multiple blades will likely allow considerably more than 20% of the airflow. If you consider an economizer as an example, setting the minimum position to 15%, doesn't mean that 15% of the airflow will come from outside. All it means is the dampers are 15% open.
Linearization programs the position versus the airflow curve into the zoning system so the dampers can go to the desired airflow without hunting to find it.
This is done at commissioning after the duct measurement and this program is stored in the master smart thermostat. It is only done once, however if a master thermostat is replaced for any reason, it should be done again.
To run a linearization routine, in the zone 1 thermostat, go to service and select the zoning icon. Highlight the word OFF and using the arrows, move to linearization and then click on "start test". This exercise takes about 5 minutes per zone.
