Stanislaus group seeks a future with cleaner air. Homemade purifiers help for now
Central Valley residents can try a decidedly low-tech way to deal with air pollution.
It involves a portable box fan and an air-conditioner filter of the same size, secured with weatherstripping and large rubber bands. The setup can be used in a small room for temporary relief from dust, pollen, wildfire smoke and other irritants. They are not meant for exterior windows, where they would suck bad air in.
Valley Improvement Projects gave a May 28 lesson in south Modesto. The nonprofit also detailed its long-range goal of cutting emissions from vehicles, farms and other sources.
The California Air Resources Board endorses homemade purifiers in dwellings that lack central AC to filter air from outside. The fans should be sturdy, with safe electrical cords and protection from spinning blades.
Classes also were scheduled for June 4 in west Modesto and June 10 in Patterson, but all the spaces were reserved. Attendees take the purifiers home for free after learning how to assemble them. Instruction is in English and Spanish.
Other interested people can purchase the components at a low cost. Home Depot sells the 20-by-20-inch fans for about $25. A six-pack of the recommended filter type, with a MERV rating of 13 or higher, is about $45.
The May 28 class took place in The Salvation Army’s Red Shield Center. VIP had help from Martha Armas-Kelly, environmental justice coordinator for Catholic Charities in Modesto.
She said the fan creates a vacuum that forces pollutants into the filter, thanks to the weatherstripping’s tight seal. A total of 10 were assembled that evening.
Armas-Kelly said the purifiers can help with frequent pollutants, or in emergencies such as the late-May chemical leak at an Orange County aerospace plant. About 40,000 residents were evacuated until the threat was controlled.
VIP sees homemade filters as an interim step toward much better air quality. The group urges tighter controls on pesticide spraying, vehicle exhaust, farmland tilling and other practices. It helped bring about the 2024 shutdown of the trash-burning power plant on the West Side of Stanislaus County.
The purifier class was led in Spanish by Edgar Garibay, a program manager at VIP, and in English by project coordinator Jose Borroel.
They said air monitoring will improve with the mobile sensors the California Air Resources Board is using in Stanislaus County and 63 other locales. They are mounted on cars that move to various spots.
Other points from the presentation:
- People with asthma are especially vulnerable to daily pollution, wildfires and other emergencies.
- Commercial trucks should be routed away from sensitive neighborhoods, and both trucks and railroads should use cleaner fuels.
- Farmers should move away from “monocultures,” where a single crop is grown over a large area.
- Farmland should have diverse plants amid the main crops. The flowers could draw insects that prey on pests, reducing the need to spray.
This story was originally published June 3, 2026 at 12:14 PM with the headline "Stanislaus group seeks a future with cleaner air. Homemade purifiers help for now."
