Posted By Malcolm Greenhouse I am about to purchase 16 portable air con units for use on hospital wards. The units have water collection trays for when the warm air is chilled and the water vapour if present condensors. The technical detail states that this water is reused by the unit under certain circumstances. The question is therefore does anyone have any experience of these small 12,000 BTU (3.2Kw) units which do not have heat exchanges placed outside the environment? Do they present a legionella risk? Are there any other risk I need to be aware of?

Posted By Ron Hunter Have you given thought to how you are going to exhaust the hot air from all these units Malcolm? Most units of this type require an exhaust outlet rather like your domestic tumble dryer.