Low-cost, do-it-yourself (DIY) portable air cleaners (PACs) are an accessible option for socioeconomically disadvantaged communities to reduce smoke exposure, but their real-world efficacy is largely untested. We conducted two pilot studies to quantify the impact of DIY and comparable lower-cost commercial PACs on indoor fine particle mass concentrations (PM2.5) in a tribal community exposed to wildfire and wood stove smoke.We measured indoor and outdoor PM2.5, indoor carbon dioxide, main door activity, and PAC usage in homes on the Hoopa Valley Indian Reservation for wildfire (n = 8) and wood stove (n = 11) pilot studies. We monitored initial PM2.5, then sequentially provided a DIY PAC (box fan with a MERV 13 filter), a commercial PAC, and a real-time air quality display with participants’ choice of either or both PACs. We quantified reductions in total indoor (PM2.5-IN) and infiltrated (PM2.5-INFILT) PM2.5 using mixed linear models and determined the barriers and facilitators of PAC usage through interviews.In the wildfire study, DIY PAC use was associated with 7–11% reduction in PM2.5-IN and PM2.5-INFILT; commercial PAC use was only associated with reduced PM2.5-INFILT (18.3%). In the wood stove study, commercial PAC use was associated with roughly twice the reductions in PM2.5-IN (20.0%) and PM2.5-INFILT (10.0%) relative to DIY PAC use. Interviews identified cost and access to replacement filters as barriers to PAC use, demonstrating the need for lower cost PACs. All households preferred the commercial PAC due to the DIY PAC's higher noise level and cooling effect in winter; 75% of participants reported that they would use DIY PACs in a different room or during warmer weather and smoke events.While both pilot studies suggest PACs reduced PM2.5, future studies in smoke-impacted communities should reflect that DIY PAC efficacy depends on prior PAC ownership, ambient smoke conditions, and PAC intrusiveness (noise, size and appearance, cooling effects) affecting user behavior.