Air quality has been shown to impact the rates of fungal infection of the airway, causing diseases such as acute invasive fungal rhinosinusitis (AIFRS), particularly in immunocompromised patients. We theorize that patients with hematologic malignancies in units with aging air handling units (AHUs) have a higher attack rate of AIFRS. Retrospective chart review identified patients with hematologic malignancy and AIFRS in two distinct and equal time periods between 2013 and 2022, representing the presence of aging AHUs and new AHUs, respectively. Cubic feet per minute (CFM) air flows, AIFRS attack rates, and clinical data were compared between the two groups and statistical analyses performed. The older AHUs produce air flow of 27,610 CFM and the newer AHUs produce air flow of 80,000 CFM. There were 18 patients with air supplied by older AHUs and 7 patients with air supplied by new AHUs who developed AIFRS. There was a significantly higher AIFRS attack rate for patients supplied by the older AHUs compared with patients supplied by newer AHUs (p = 0.033). The patients supplied by the older AHUs tended to be younger. The white blood cell counts, absolute neutrophil counts, and the mean time to diagnosis did not differ between the two groups. To our knowledge, this is the first study to examine AIFRS in immunocompromised patients' inpatient environment. Further research should explore whether higher CFM AHUs can decrease this disease among our most vulnerable patients. 3 Laryngoscope, 134:4466-4470, 2024.