1. Run filters 24/7. This reduces filter life more quickly and seems like it might provoke staff to unplug it for fear of the extra power usage. It's usually considered to be a bad idea to rely on filters staying on 24/7.
2. On-board timer function. Unit possesses functionality to turn itself on and off at programmable times.
3. People. While some schools/districts might be willing to instruct custodial staff to turn the filter on and off, keeping the filter operational is best accomplished by eliminating any burden on the teacher, staff, or students. Otherwise it will get neglected and forgotten. Some parents have had success convincing the teacher to rotate “Clean Air Captains” among the students, or to assign this important role to one student (e.g., as a STEM/leadership exercise, empowering students to better understand and control their environment’s health and safety).
4. Apps. Many consumer-grade filters (e.g., Levoit) can be connected to WiFi and controlled by an app, which has the benefit of letting you monitor and control it from anywhere. But most/all need to be connected "directly" to the school's network, and not through whatever hotel/airport/cafe-style "captive portal" the school uses (since the filter doesn't have an interface to sign in). This means negotiating with facilities to give you the WiFI password to the school's internal network, and some administrators will frown on this. If you can manage it, though, remote access lets you confirm the filter is operating when expected.
5. Timed outlets. This may be the option most likely to succeed. If WiFi is inaccessible due to school restrictions, there are smart plugs that can be programmed with Bluetooth instead, such as this Govee model. A 7-day programmable light timer like this one also works well, but cannot be secured as well as the Govee (which can lock out its on-unit button). Naturally, this limits filter selection to those that turn back on after power interruption, like Clean Air Kits, AirFanta, Nukit Tempest, and some Coway and SmartAir units. Unclear if there are any other "commercial" filters that power back on automatically and would work with a timed outlet, but Levoit and Medify units do not.
6. Motion. Weakness: all it takes is something blocking the sensor and the filter is effectively disabled. And that's even more likely if the sensor is at the outlet, like this motion activated plug. PIR motion sensors (like this one) could be mounted to the filter itself to minimize the risk of blockage ... but these are limited to units that use barrel power connectors.
7. CO2. From the "throw money at it" department ($100), a CO2-sensing plug might be perfect for efficacy and administration-friendliness. You can configure precisely what CO2 ppm levels to turn a standard outlet on or off, so it works for any filter that powers back on when power is restored, not just the Tempest. And because it can't be blocked (like motion), it’s easier to "harden" for the classroom by putting it in an enclosure of some sort (not airtight, obviously), but placement nonetheless influences its effectiveness.

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Back to the Safe Indoor Air Resources homepage at safeindoorair.org.

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