Methods: This analysis included households enrolled in a respiratory virus transmission investigation during September 2024-January 2025. All households had at least one confirmed RSV or SARS-CoV-2 infection. One adult per household completed a ventilation survey at enrollment. We assessed housing types, ventilation system characteristics by housing type using Pearson’s chi-squared test, and ability to make ventilation upgrades.

Results: Of 237 households, 153 (65%) were apartments/condominiums, 73 (31%) were single family homes, 9 (4%) were duplexes/townhomes, and 2 (<1%) were other. Central heating/cooling systems with filtration and ventilation (HVAC) were present in 95 (40%) households, while 141 (60%) households had heating/cooling systems without filtration and ventilation (e.g., radiators). Of those with HVAC, 74 (78%) were willing to upgrade filters, and 58/74 (78%) reported being able. Portable air purifiers were used in 80 (34%) of all households. Although 202 (85%) households were willing to purchase one, only 137/202 (68%) reported being able. Apartments/condominiums were less likely to have HVAC (29/153, [19%]) than other housing types (66/84 [79%]; p<0.001). Reported barriers to improving ventilation included cost (128 [54%]) and limited autonomy due to housing type (47 [20%]).

Conclusion: These findings provide valuable context for ventilation recommendations to enhancing indoor air quality. Future ventilation guidance could be improved by addressing household barriers.