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mick2me
08-01-2008, 02:26 PM
Research in another area got me thinking, and prompted me to consider...

Is there any level of risk of Legionella in domestic split air conditioning units? :confused:

paul_h
08-01-2008, 02:51 PM
Legionella breeds in water water mate. It was only an issue in condenser cooling towers on buildings, not the AHUs or chilled water coils.

Argus
08-01-2008, 03:21 PM
.

Analyses of the content of ordinary, free condensate water reveals a mix of bacteria, pollen, organisms etc, including legionella, that occur naturally in the environment in any case.

The question that arises for health and safety assessments is, does the presence of legionella provide the potential for a viable colony to develop and if it does to transmit itself to a susceptible host.

So, is there enough condensate water, with sufficient nutrient at the optimum temperature, to form a breeding legionella colony and a means of transmission available in a small split system?
There’s no evidence to suggest that there is a risk in these machines.

There’s plenty of information on L8 assessments available in the UK


.

expat
08-01-2008, 06:22 PM
You also have to remember that the colonies start to breed at a certain temperature and are only dangerous when suspended in water vapour in the air as they enter your body through your lungs.

Steam in a shower could therefore be a problem but water tanks are required to raise their temperature to over 60°C at least once per day to ensure the destruction of the bacteria.

Another law here in France is that the water must not be able to leave the tap at more than 50°C hence the mixer tap at the hot water outlet on my hot water tank.

As for Legionella risk with domestic air con, I don't see how but customers like to see Anti Legionella written on the aerosol that you clean their evaps with,... power for the cause;)

frank
08-01-2008, 09:40 PM
Here's a couple of links Mick

http://www.nottinghamcity.gov.uk/test_new/CBSS/g_lib/Summer04_1Legionella.ppt#1

http://www.daikin.co.uk/faq/items/legionella.jsp

And don't worry - if you contract the disease it can be cured with antibiotics or J2O :D

mick2me
10-01-2008, 09:09 AM
Here's a couple of links Mick

http://www.nottinghamcity.gov.uk/test_new/CBSS/g_lib/Summer04_1Legionella.ppt#1

http://www.daikin.co.uk/faq/items/legionella.jsp

And don't worry - if you contract the disease it can be cured with antibiotics or J2O :D


AAAAaaaaaaaarrrrrrrrgggghhhhhh! :eek:
Death By Power Point!!!

Give me Legionnella anyday :(

Pass the J2O!


Anyway I was doing some research, about Legionella in Hydroponics systems, and it got me thinking about Domestic systems.

Regarding the former, High Humidity is often present,
Could this increase the risk?

And what if the water is thrown about?
I have seen water from hydroponics systems tipped out of a second floor window!

Re the latter, I think Frank answered it certainly on DAIKIN units.

Question:What about legionella

Answer:Daikin e.g. does not use water in its air conditioning systems. So no harm for humans can be caused.

Argus's reply is interesting, because it shows a level of risk, (Perhaps low).

Argus
10-01-2008, 11:22 AM
And what if the water is thrown about?
I have seen water from hydroponics systems tipped out of a second floor window!



No problem here, as long as you shout, “Below!” immediately after you chuck it.






Argus's reply is interesting, because it shows a level of risk, (Perhaps low).



In my opinion the risk in small units like this is vanishing, you can find the Legionella bacteria in the wild in almost any body of water world wide. Streams, puddles, Duck ponds – you name it.

The problems arise when it becomes a hazard as I described. That’s what risk assessment is all about – assessing the risk and seeing if it’s dangerous or not.
In this instance - probably not.


.

hendrag
14-01-2008, 07:25 PM
Legionella is the bacteria which causes legionnaires disease, the legionella bacteria lives in warm water (37 degrees C). If we breathe in water vapour containing legionella bacteria we can contract legionnaire’s disease which is often fatal.

It is important to remember that the split units like Artcool have no warm water anywhere in the system and do not emit water vapour. It is not possible to contract legionella from one of these systems.

Legionella used to be common in water tower systems used for huge air-conditioning systems typically used in hotels and hospitals. Nowadays these systems are incredibly tightly regulated to eliminate outbreaks.


regards

hendrag LG tech support

Jimbo!
15-01-2008, 12:25 AM
which figures, cause otherwise there would be a risk from every sink trap I suppose.