ozone generator for cleaning car air conditioning

[arekm]

Hello.

I'm looking for ozone generator projects based on some chinese parts ( http://www.aliexpress.com/wholesale?SearchText=ozone+generator+220V ). Something with >= 5g/h efficiency.

Did anyone knows such, tested project? Not sure if these chinese parts specifications are true.

Example part:
http://www.aliexpress.com/item/LF-22021G-AC220v-21g-ozone-generator-ceramic-plate-3-power-supply-air-source-air-purifier-ozone/997076116.html

or

http://www.aliexpress.com/item/LF-2203BFMT-2pcs-HOT-7g-h-220v-3-5g-2pcs-Internet-cafes-air-purifier-Ozone-disinfection/1270691853.html

Also looks like there are 4 types of generator elements:
- Quartz tube
- Ceramic tube
- Enamel tube
- Ceramic plate

Which one is the best for DIY work? Some require air pump to be connected while some seem to do not require that. I woner if regular fans for air blow + quartz tube/ceramic plate would work well.

[rexxar]

This seems like a bad idea to me. Ozone deteriorates most plastics and rubbers fairly quickly.

Why do you need to clean your car's AC anyway?

[arekm]

This seems like a bad idea to me. Ozone deteriorates most plastics and rubbers fairly quickly.

This is not an new idea. It's widely used in industry and AFAIK most effective one.

Why do you need to clean your car's AC anyway?

Because it eliminates bad odours and kills harmful bacteria in car AC system.

[Dave]

I am guessing there is a foul smell coming from the car's vents when you turn on your AC? Smells sort of like cat piss, right?
I've had this problem last year, it was mold growing on the evaporator. It was in the summer, I mostly used the car for short trips and had the AC running at full blast. The condensation was there all the time.

The proper solution would be to go to the repair shop, they seal the vents and fill the whole system with some aggressive cleaning foam that gets rid of the mold.
The simple solution is to set the AC to heating, run it at full power and leave it running for 15-20 minutes. It should kill the mold and remove the foul smell.

[arekm]

That smell is due to bacteria. Repair shops use cleaners in form of fluid (with very long tubes put via vent holes to be able to spray direcly onto evaporator etc) or... ozone generators.

Ozone has advantage of going everywhere and killing bacteries everywhere in the car (start ozone generator inside the car for for example half hour; turn on air conditioning in closed loop mode; close doors, windows)

[Fank1]

You need to know that OZONE attacks rubber.
The seals, hoses etc won't like it.

[VK5RC]

Ozone is also really good at oxidising your respiratory mucosa,  if you have a microbial problem with the air conditioner,  I would be looking at drainage of the evaporator exchanger area. 

[FrankenPC]

Side note:  I had a smelly A/C problem when I purchased my recent used car.  I jacked into the CAN bus and enabled the after-engine-stop blower execute feature.  After that the smell just went away naturally.  Mold/mildew die in a dry environment.

I tried the spray can approach and also put our whole room ozone generator in the cab for an entire day and the smell didn't go away.

[SeanB]

I did my one by just using a sprayer to feed some biocide into the inlet after the filter and letting the fan blow it into the core till the drain line was running it out, then left the fan running on high for a while to dry it. Used around 10l of the diluted solution, and the final water out was clear and carried a lot of sludge as well initially. No more smell, and air flow is a lot better as well with the core clean.

[paulhm81]

I have the same problem. In the summer with short trips - same smell. I tried a lot of things - cans that you live int the car for 1/2 hour with the ac on and reciculate and the problem returned a few days later. I tried the spray with the long hose and it was good for a week. I went to a professional with an ozone generator and the put a hose with the ozone through a windows and let the car running with ac on for a few hours. It was all good for a month. I put a powerful ionizer (that is supposed to create ozone too but in a small quantity) under a seat and let it on sometimes over night. It kind of kills all smells but not on the long run. The only way to manage this problem is to stop the ac when you approach your destination so the evaporator has time to approach a normal temperature. By the way, I have a VW Golf 5 and the forums are full of this problem with no real solution. If anyone knows something, please post it!!!

[arekm]

You need to know that OZONE attacks rubber.
The seals, hoses etc won't like it.

Ok, wasn't aware of that.

I don't understand why repair shops use ozone generators so widely then... weird

Maybe small concentration is a key here? These machines generate like 5-10g/h and usual AC cleaning session is about 0.5-1h.

[SeanB]

They use enough ozone to kill bacteria, and then 6-9 months later you find that the rubber piping and plastic ducting is starting to develop cracks and disintegrate. Most people do not associate the two, and as the plastics used are generally buried inside, the manufacturer would not have used a UV stabiliser in them either, so they are more susceptible to being damaged by ozone. Even silicone tubing is destroyed by it, it even makes PTFE brittle.

the proper method is to strip the dashboard and take the core out, clean it and then apply a biocide layer to it, then put it back. Only problem is the core is the first part placed when assembling the interior, so to get it out you start by taking the steering wheel off, then removing the whole dashboard and centre console, then you get to it. As most is assembled with clips you will break some when taking apart, and may have to replace plastic mouldings or make alternate fastening methods on reassembly. That is 5 hours labour to remove, and the same to put back, using the proper tools and knowledge of where the clips are located and how to open them without breaking them.

[cs.dk]

I've used ozone a lot of times, with no problems. It is widely used here in Denmark to clean AC systems.

Taking the dashboard out, can be alot of work.. Looks like this on a Citroën Xantia - The heater-asssebbly isn't taken apart here.

[arekm]

Anyway back to main subject. DIY ozone generator based on chinese components looks very easy to do:


(what is that can with sticker on it?)

[N2IXK]

Ozone is NASTY stuff to work with.

I maintain a couple of medium sized ozone generators of the size used for large swimming pools as an alternative to chlorine.

The output gas stream will very quickly rot away almost every type of tubing short of stainless steel.  Silicone, viton, chem grade nylon, PTFE, all get stiff or degraded some way in a few months to a year.  Even tried some $$$ stuff our chem department had that is usually used with HF or fluorine. It lasted about 18 months.

That car interior pic brings back some memories.  Had to replace a leaking heater core on my truck, and like most modern vehicles, i swear they start the vehicle assembly process with the heater core, then build the rest of the vehicle around it! 

To access the thing, you have to basically gut the interior. Steering column, entire instrument panel, shifter console, most of the trim, etc. Essentially stripping the vehicle to the firewall, to get access to the heater core. A/C system had to be evacuated, because the heater core is inside a box along with the A/C evaporator coil and the blower motors and the vacuum solenoids/ flaps that control the whole HVAC system. It has to be pulled off the firewall to be opened.

For the few extra bucks, I swapped out the A/C evaporator and the blower motor while I had the thing apart, because I didn't want to do that job over again any time soon. Took the better part of a 3-day weekend with a helper.

I really think that they should make the folks who design this stuff actually have to put in some time doing teardowns/simulated common repairs on the first few prototypes of their new designs.  Would certainly improve the "design for serviceability" aspect.

[rob77]

i'll comment on the car AC (got no experience with ozone - but that doesn't sound good to me )

basically there are 2 common ways to disinfect (kill all the bacteria) in you car AC.

1. buy one of those sprays for this job - heat up the car;s engine - turn on the heating to max - squit the whole spray as deep as possible through the vents in the center of the dashboard (the spray is coming with a long "nose") - those vents are the closest to the evaporator - select internal recirculation and turn the fan to some higher speed and close all the doors  (and windows) -  keep in running  for approx 20 minutes. - enjoy the odorless AC

2. use one of those disinfection devices dedicated for the job - procedure is the same - but instead of a spraying into the vents, that device is generating the disinfection fumes (placed inside the car). many car repair shops are using this method - because it's cheaper in terms of consumables.

[KJDS]

Every car dealer that I know in the UK uses the following mehod.
Buy a can of Oust, or equivalent from the pound shop. It's a spray for neutralising odours on fabric.

Set aircon to recirculate and on warm. Squirt entire can into the car, spaying it all round. Shut the door and leave for half an hour. I've never known this fail.