Like many things in life, it depends.
If you have multiple zones, or HVAC units, then it is possible to install Ecovent in part of your home.
If you have one zone in your home then you will see the best results if you replace each vent.
The system works optimally when it's installed in an entire zone of your home; in order to help a room reach a desired temperature, we strategically open or close vents in other parts of the home to redirect the airflow.
An incomplete system may not give you complete control over your comfort and, in some cases, it will dramatically reduce Ecovent's ability to achieve the target temperatures you set.
If you're interested in a partial system, we're happy to talk through how it might work. Please feel free to reach out to our support team at firstname.lastname@example.org