The presence of biofilms on the cooling coils of commercial air conditioning (AC) units can significantly reduce the heat transfer efficiency of the coils and may lead to the aerosolization of microbes into occupied spaces of a building. We investigated how climate and AC operation influence the ecology of microbial communities on AC coils. Forty large‐scale commercial ACs were considered with representation from warm‐humid and hot‐dry climates. Both bacterial and fungal ecologies, including richness and taxa, on the cooling coil surfaces were significantly impacted by outdoor climate, through differences in dew point that result in increased moisture (condensate) on coils, and by the minimum efficiency reporting value (MERV 8 vs MERV 14) of building air filters. Based on targeted qPCR and sequence analysis, low efficiency upstream filters (MERV 8) were associated with a greater abundance of pathogenic bacteria and medically relevant fungi. As the implementation of air conditioning continues to grow worldwide, better understanding of the factors impacting microbial growth and ecology on cooling coils should enable more rational approaches for biofilm control and ultimately result in reduced energy consumption and healthier buildings.

中文翻译：

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空调冷却盘管上的细菌和真菌生态受到气候和建筑因素的影响。

商用空调（AC）的冷却盘管上存在生物膜会大大降低盘管的传热效率，并可能导致微生物雾化到建筑物的居住空间中。我们调查了气候和交流运行如何影响交流线圈上微生物群落的生态。考虑了40个大型商业AC，它们代表了温暖湿热的气候。盘管冷却表面上的细菌和真菌生态系统，包括丰富度和分类单元，都受到户外气候的严重影响，露点的差异会导致盘管中水分（冷凝水）的增加，而最低效率报告值（MERV 8 vs MERV 14）的建筑空气过滤器。基于靶向qPCR和序列分析，低效率的上游过滤器（MERV 8）与大量致病菌和医学相关真菌有关。随着全球范围内空调应用的不断增长，更好地了解影响冷却盘管上微生物生长和生态的因素应能采取更合理的生物膜控制方法，并最终减少能源消耗和建设更健康的建筑。