Re-using ductwork

• By: Craig Booth
• On: 23/04/2009 16:02:03
• In: Uncategorised
• Comments: 1 Add

An interesting warning story from Ontario, Canada where new air handling units fitted onto existing ductwork caused visible dust to be blown out (into hospital operating theatres) and settle on the room surfaces.

That's a reasonably well-known, and easy-to-predict, problem.

The twist in this case is that the dust being blown out was eventually identified as zinc oxide, i.e. presumably the material of the galvanisation layer of the ductwork.

The ductwork is described as being of 1961 vintage, and rusty in parts, and so it's easy to imagine that it would be vulnerable to 'white rust' corrosion. Especially as operating room systems usually operate in northern climes with considerable humidification.

The professional duct cleaning contractor would:

1. exclude responsibility for any hidden corrosion, if he's quoting site unseen, as a standard contract term
2. carry out a thorough inspection as soon as he gets a chance to see what he has to deal with
3. if he finds poor surface condition, he could offer extra-thorough scrub-brushing followed by remote, robotic airless spray application of a lock-down coating

The professional in this business should ensure that people don't have this sort of bad experience, by giving good advice

There are such huge benefits to be gained by hospitals', and facilities' managers in other settings, from re-using ductwork rather than ripping it out and replacing it.

Not least is the massive time-and-disruption saving (8 operating rooms 're-planted' over one Easter weekend), never mind the enormous cost benefit - if done properly!