halacha - Air purifier with LED sensor on Shabbat

Would one be allowed to use an air purifier with an LED smell indicator sensor on Shabbat if bringing in odors near the purifier with outside food or other odorous things could or most surely would trigger an LED sensor to go off? The resulting activation of the LED lights would be undesired and the trigger would technically be an indirect delayed activation unlike walking directly in front of a motion LED sensor. The benefit of the purifier would be to control allergy symptoms whereas without it allergies would be worse. Also there is no way to disable the LED lights.