The Setra LITE on the front of the AIIR Watch is measuring the pressure drop across the HEPA filter inside of the AIIR Watch unit. This is unrelated to the negative pressure being created in the room. If the pressure drop across the HEPA filter gets too high, the Setra LITE on the AIIR Watch will glow yellow indicating it is time to replace the filter. Replacement HEPA filters are ordered from Setra via part number 380415.
The Setra LITE on the AIIR Watch also provides indication on the status of the UV-C bulbs inside the AIIR Watch unit. Once the UV bulbs reach 7500 hours of run time the Setra LITE on the AIIR Watch will glow red. The life of the bulbs is 8000 hours, leaving time to replace the bulbs. Replacement UV-C bulbs are ordered from Setra via part number 380416. If a UV-C bulb malfunctions inside the unit, the Setra LITE on the AIIR Watch will also glow red indicating the need to investigate and potentially replace the bulb.
The AA and NA versions of the AIIR Watch Negative Pressure unit include a standard Setra LITE plus Quick Mount Kit accessories. This is to be installed on the wall outside of the isolation space for measurement of the negative pressure created in the room. This Setra LITE is monitoring the pressure status of the room only.