Start with the scope of your home
For homes in San Luis Obispo, Paso Robles, Atascadero, Arroyo Grande, and nearby communities, choose filtration around the equipment you have and the room you want to clean. A home without a ducted central system still has a practical option in a properly sized portable purifier.
CDC includes indoor air filtration among its measures to reduce exposure. Filtration is not a guarantee against infection. CDC Valley fever prevention
A documented record year on the Central Coast
The county's April 8, 2025 announcement reported 482 cases in 2024, compared with 244 in 2023, and described 2024 as a record year. These are the figures in that dated announcement; later surveillance revisions may differ. They should not be presented as a current 2026 trend. SLO County announcement
The county explains that the fungus occurs in local soil as well as neighboring regions. A coastal address is not a reason to dismiss Valley fever, but countywide cases do not establish identical exposure conditions in every community.
SLO County announcement · Source checked 2026-09-06
If you normally cool the house with open windows
During a dusty event, consider how you will keep the occupied room comfortable with exterior windows closed. A portable purifier cleans particles; it does not provide air conditioning. Do not let a filtration plan create unsafe indoor heat. If keeping the home closed is not practical, arrange a suitable cooler indoor location while addressing the conditions.
For a house with little or no ducted cooling, a room purifier can be evaluated without first installing a whole central system. Cooling needs and filtration needs can be assessed separately, then combined in a proposal if both genuinely require work.
Size a bedroom or home-office purifier
An illustrative 150-square-foot room has a starting smoke CADR target of 100 CFM using AHAM's two-thirds rule and a standard ceiling. A 300-square-foot combined living space starts at 200 CFM. Those are general sizing examples, not a Valley fever protection threshold. AHAM sizing guidance
| Space | Product to compare | Published specification |
|---|---|---|
| Small bedroom or office | Coway Airmega 100 | 108 CFM smoke CADR |
| Larger shared room | Coway Mighty AP-1512HH | 233 CFM smoke CADR |
| Larger room with app controls desired | Levoit Vital 200S-P | 250 CFM listed CADR; confirm the exact model's rating |
Check the Airmega 100, Mighty, and Vital manufacturer pages for current specifications and offers. Budget for replacement filters. Quieter speeds usually provide less cleaning than maximum-speed ratings, and the current Vital page qualifies its HEPA-grade claim to Sleep Mode.
AHAM sizing guidance · Source checked 2026-09-06
When an installed filtration upgrade makes sense
If you already have ducted heating or cooling, ask whether a compatible higher-efficiency filter can use the existing cabinet. MERV 13 is a useful target when the system can support it. For a cabinet change, the contractor should explain space, access, connections, and airflow checks. EPA filter guidance
For a home where the central fan does not run much during mild weather, ask how the proposed filtration would operate between heating or cooling calls. A cabinet does not clean air merely by being installed. Include any change in fan electricity and comfort in the discussion.
Ask for separate prices for assessment, filtration-only work, and any cooling-system addition. A household buying its first AC is considering a different project from one upgrading an existing return-air filter.
EPA filter guidance · Source checked 2026-09-06
Combine local precautions with the equipment choice
The county advises limiting dusty exposure, taking precautions when dusty outdoor activity is unavoidable, and using closed windows with recirculating vehicle AC when driving through dust. Indoors, the goal is to reduce the dust entering and clean the air circulating through the occupied space. County prevention advice
Our shared evidence and buying guide explains why an air-filter efficiency claim is not an infection-prevention claim. No purifier here is established to eliminate Valley fever risk.
For whole-home work, request an indoor-air-quality assessment in SLO County. Name the service community and say whether you have ducted HVAC. The provider confirms availability and cost. For a room-only purchase, compare the exact models and replacement-filter prices above.
County prevention advice · Source checked 2026-09-06
Persistent symptoms need a medical conversation
Tell a healthcare professional about persistent cough, fever, or unusual fatigue and recent time around local soil or dust. Seek urgent care for severe breathing difficulty. An air purifier cannot diagnose or treat an infection. SLO County health guidance
Related: Kern County and Fresno County.
SLO County health guidance · Source checked 2026-09-06
Editorial review: 2026-09-07