parparsons,

If your replacing an existing ice maker you may not need to use it. Its only used for the older porcelain interior cabinets and not on the ones with the plastic interior.

I would install the ice maker and if your getting hollow cubes find a way to mount it so it allows more cold air to flow over the tray. Its basically used to direct more air flow over the tray.

I have never had to use it because there has always been sufficient airflow.

Also be sure you have no packages are stacked around the vent or ice maker to prevent airflow.