The Filter sensor monitors the main return filter using pressure. Other filters in the home use timer-based reminders.
Upon setup, the system profiles your HVAC system. Once a member indicates a new filter has been installed, the system monitors that first lifecycle to determine the min and max static pressure, as well as the true runtime hours.
How Pressure Measurement Works
The Filter sensor measures static pressure behind the filter, comparing pressure when the blower is off versus running. The difference is the pressure loss across the filter. As the filter collects debris, this pressure loss increases.
Calculation Methodology
Filter life starts as runtime-based. After the member indicates their first filter change, the system uses both pressure and runtime to determine life remaining, providing personalized replacement timing.
Detecting Other Issues
Pressure monitoring also enables detection of other system changes. A sudden increase in pressure may indicate a system blockage or other airflow restriction.
What Affects How Quickly Filters Load
Faster loading:
High system runtime
Dusty environments
Pets
Construction or remodeling
Higher MERV-rated filters
Slower loading:
Lower system runtime
Clean environments
Lower MERV filters
Larger filter surface area
What Members See
Members see a filter life percentage in the Filters section of their app. For the main return with the Filter sensor installed, this percentage is based on actual pressure measurements. When filter life is low, members receive a notification and can order the correct size directly through the app.
