A lower cost alternative to purchasing a HEPA type stand alone filter would be to replace your cold air return filters on your homes HVAC system. Most of the stand alone HEPA (plug in appliance type) filters are ineffective for rooms or livable space exceeding 200 sq. ft.
I would recommend the filter under the trade name “Filtrete” manufactured by 3M with a performance rating of least 1250. Forget any of the fiberglass ones, they are worthless. Home Depot in Encinitas has them in stock as of yesterday for about $16 – $20 depending on the size and rating.
You can then run just the fan or AC to circulate the air within your home after you shut all windows and doors.
