Legionnaire's Disease linked to driving, screenwash The Health Protection Agency is calling for more research to see if Legionnaire's Disease is connected to not using screenwash in your windscreen water reservoir. An HPA spokeswoman said: "This preliminary HPA study suggests a strong association between a lack of screen wash in wiper fluid and the incidence of Legionnaires' …
... yet still present in 20 percent of cars? I smell "screenwash" marketers about ... I dread to think what's going to happen when someone with a BA in Marketing discovers that Anthrax is detectable in soil samples taken from virtually 100% of all cattle ranches, world-wide ...
I don't see why. The only water involved in a car air conditioner is that which condenses on the evaporator and will dry out between uses. The type of air conditioner that causes Legionnaire's Disease has a permanent body of warm water which is kept topped-up as it is sprayed around and lost due to evaporation. Those are the conditions the bacteria will flourish and spread.
This is a moribund news article, I watched the BBC News video earlier and it really is a dead donkey. I think almost everyone always uses screenwash to some extent when they top their washer bottle up; the amount of crap and grime that lands on windscreens in daily driving is so bad these days you need some kind of surfactant and detergent to work with the water, even in summer. I personally use a 80/20 mix in summer and 60/40 or even stronger concentrations in harsh winters.
I can't be bothered to explain this in more depth as I'm at work, but a poorly maintained aircon/climate control in a car is as dangerous, if not more, to your health.
http://www.lvvservices.com/aircon.htm explains it fairly well. Rule of thumb: if you have smelly aircon, time to get it recharged and cleaned.
Or just pour some beer into it...
Not if the A/C drain gets blocked, as can commonly happen to non-professionally maintained vehicles where even the most diligent owner may simply not know the A/C drain needs to be checked periodically.
Learned this from Click and Clack by listening to Car Talk. You can find 'em on the web.
The drain below the windshield/screen is typically not far removed from the air intake of the HVAC system in a typical vehicle. I'd guess that there is a baffle to keep liquid from being spritzed out of the air outlets, but that's about it. The demand for air is satisfied by pulling it through that drain/vent grid underneath the windshield/screen. If you're using water for the washer unit and it's stagnant, there can be almost no doubt that bacteria will find its way into the passenger compartment through the ventilation system.
As far as bacteria growing in the A/C evaporator coil goes, consider the following...air from a wide variety of sources gets pulled in over that coil, bringing with it dust, pollutants and some bacteria. As most modern cars have tightly packed engine compartments (where the majority of the A/C and air handling components are located), a lot of heat builds up in there when you've stopped after enough driving to warm the vehicle up. The warm, damp environment inside the evaporator coil box is conducive to bacteria growth. That's why the air coming out of the A/C vents may be smelly when you first turn the system on.
The 1996-2000 Chrysler minivans have a big problem with this.
It's easy enough to stop this, however. About a mile before you reach your destination, turn the A/C off and let the evaporator coil dry out a little bit. Even on a wickedly humid day, the incoming air can still dry the evaporator just enough to help alleviate the problem.
First of all, no "professional" driver would ever use plain water in his washer bottle, its useless at best.
Secondly, tap water in the uk has chorides in it to prevent it from going stagnant. in a closed system like a car screen wash, it would take months for the stuff to evaporate off to a level that would allow bacteria to breed.
@handle, seems logical but in reality, car A/C systems used to have a lot of problems of having musty, moldy odors. In some cases the system was redesigned so the condensate is drained out instead of building up. In other cases, on the newer computerized A/C systems they will run the climate control to help make sure it's all dried out.
As for Legionaires being uncommon, indeed I think it's not particularly virulent so there has to be an extraordinarily high concentration for it to be catching.
I wouldn't dream of using water here, that's for sure! It has gotten down to -40 here (-40F=-40C btw...) and gets down to 0F (about -20C) almost every winter, I'd be mad to even think of it.
The Register 
Biting the hand that feeds IT
Copyright. All rights reserved © 1998–2024
