I was chatting with a plumber recently about my plans to install solar at home. Maybe he thought I was a bit cocky but he came out with a dire warning that Legionella is going to be the next big obsession in the plumbing world.
Now I'm no biologist but I know a bit about bacterial growth in aqueous media from my job. My understanding is that all the infamous outbreaks of Legionella have been in ill-maintained, open, air conditioning systems where airborn bacteria have found the ideal conditons they need for reproduction and have settled to start a family.
A domestic HW system is closed and assuming no bacterial contamination prior to filling, it receives water from the mains, which may not be sterile but is treated to a high standard so that even if that water sat for many days at the ideal 35 degrees in the cylinder it's doubtful that bacteria would grow. In normal use fresh, treated water is entering the cylinder all the time. Most Mediterranean homes use solar and I doubt if their incoming water is treated to the high standard we enjoy in the UK, yet we have never heard of anybody there catching Legionella from their shower - the media would have a field day.
So who or what is driving this new paranoia amongst plumbers? Should I be concerned? The system I plan to install (Vridian Solar) has a dry panel, which drains down in extreme heat or cold so could be deactivated if we went away on holiday.
Now I'm no biologist but I know a bit about bacterial growth in aqueous media from my job. My understanding is that all the infamous outbreaks of Legionella have been in ill-maintained, open, air conditioning systems where airborn bacteria have found the ideal conditons they need for reproduction and have settled to start a family.
A domestic HW system is closed and assuming no bacterial contamination prior to filling, it receives water from the mains, which may not be sterile but is treated to a high standard so that even if that water sat for many days at the ideal 35 degrees in the cylinder it's doubtful that bacteria would grow. In normal use fresh, treated water is entering the cylinder all the time. Most Mediterranean homes use solar and I doubt if their incoming water is treated to the high standard we enjoy in the UK, yet we have never heard of anybody there catching Legionella from their shower - the media would have a field day.
So who or what is driving this new paranoia amongst plumbers? Should I be concerned? The system I plan to install (Vridian Solar) has a dry panel, which drains down in extreme heat or cold so could be deactivated if we went away on holiday.
