Reply #48: I write promo material for natural gas cooling technology [View All]

[LiberalEsto]

and from what I've heard and read, the legionella problem results from bacteria growing in excess condensation and poorly maintained condensation pans in large commercial cooling systems. Once circulating air in the HVAC system picks up that bacteria, it spreads all over a building and into people's lungs.

Solutions include increased maintenance and cleaning, piping the condensate to another location, more ventilation, and/or installing desiccant dehumidification that will reduce moisture in the air, and by doing so, condensation. Desiccant systems are costly and not usually built for residential use.

I'm not familiar with legionella being an issue in residential cooling systems, although uncontrolled condensation and moisture can lead to serious mold problems in homes.

SEMCO and Munters are two major manufacturers of desiccant dehumidification.

I think there are also devices that purify circulating air using ultraviolet light.