Legionnaires' disease & hot water systems

[desA]

I'm currently undertaking a study into Legionnaires' Disease and hot water systems.

Over the years, a number of my Australian & NZ colleagues have explained that Australian ?law? requires hot water, in storage, to be heated about 62'C for a certain time period - once per ?week?.

If anyone has literature to hand, or links, which can direct me towards these legal requirements &/or recommendations, I'd be most grateful.

Thank you in anticipation. :)

[chemi-cool]

http://www.amm.co.uk/files/factsabout/fa_leg.htm

http://www.admin.ox.ac.uk/safety/UPS0707.shtml

Des, there are tons of papers on the internet.

My simple philosophy says that the more we protect ourselves - the more vulnerable we are.

[tmm]

desA, if you type the following link: www.hse.gov.uk (http://www.hse.gov.uk) & search for 'Legionella Approved Code of Practice L8 you can download for free.
Or the ISBN is: 9780717617722.

I passed my quals from this guide.

tmm

[desA]

Thanks so much Chemi & tmm. Those are an excellent start.

So little really seems to be known in regards to this in regards to hot water systems in some countries. Apparently Australia & NZ have legislation that applies to heat-pumps as well. (To the best of my knowledge).

[tmm]

desA, in the UK to maintain compliance you must store at 60 & distribute at 50. If you read the guide the only temperature at which you kill ALL of the legionella is actually 70. Since you mention heat pumps you will instantly recognise the problem with flow temps at 45!

Don't start me on AWHP/GSHP's!

tmm

[NoNickName]

Legionella is only dangerous when water is in contact with air. In a closed circuit for heating, legionella does not develop.

[Peter_1]

I know for Belgium that you not only have to heat the water to - I think - 65 °C on a regular base - how regular , I don't know - but it must then also flows through all the tap points. So you must install a loop the point most far away from the boiler and a pump on that loop.

[Peter_1]

Searched once fro Belgium and read in a thesis to obtain a Master degree.
Some highlights

You have low, medium and high risk installations.
Chemical desinfection not allowed, only heating
In Europe , the EWGLI group. (European WorkGroup Legionella Infections)
Additionally chemical is allowed
Waterhoses for fire not included but connected to a different waternet that is used only for fire.
Not necessary for private homes.
Practical experiences temp60 °C, 2 minutes flushing, then 65 °C and 1 minute flushing and finally 70 °C and 30 seconds.
Cold water lines always <25°C.
Warm water always >55°C and > 60°C when leaving boiler
When mixing, only 5 m tube length and < 3 l volume (clinics < 1 l)

[desA]

Thanks so much Peter. Excellent review of the current status in Europe. This seems to be an emerging area - certainly of great interest to me.

If you are able to PM me details of the Master's Thesis you refer to, I'd be most grateful.

[refcon32]

Hi there doing water quality at work myself. Document called L8 you will be able to download from net. Water coming from tap should be at least 50 deg C after 1 minute of running and should return to hot tank at 55 deg C. Shower heads, shower taps and dead legs have to be flushed once a week.

[MilosBog]

In Germany there is a bunch of standards regarding preventing legionella. Legionellas are dangerous only when it is breathed.
ALso, it is not just the heating up to the certain temperature. If water content in the pipes is more than 3 liters, than there is a need for a recirculation or if loop system is used, than there is no need for a recirculation pipeline. Which system is installed? If you have a big project, than take care about it, if not, be COOl

[desA]

Thanks for the information.