Air conditioner mold odor

[Rxman47]

In my Hunter 336 when we switch on the A/C we get very strong odor of mold.
Probably the PO didn't use the fan to "dry' the ducts before he left the boat.
Have searched knowledge base to find how to clean/kill the mold in the ducts,
can't find anything.
Can any one out there give me some ideas??
Thanks
John

 

[novelman17130]

John,
Buy or rent a small Ozone generator and run it for at least four hours with the vent fan on. Your problem will be gone. I have a source if you are interested.
Novelman

 

[Chuckbear]

John, The odor is most likely coming from the drip pan for the condenser. Give it a thorough cleaning then go to Home Depot and get some of the tablets made to be put in the AC pan. They clean out any slime, etc. build up and will help to keep the odors down. Also be sure the drip pan drain fitting is not leaking and water is not collecting around the bottom of the unit in the locker. It will do no good to try and get rid of the odor if you don't get rid of the cause. Chuck

 

[kloudie1]

Just be careful to not put a bunch of chlorine in there since that will corrode the pan and eventually the evaporator tubes as well.. Swimming pool algecide (dimethyl, benzyl, ammonium chloride looking stuff, not chlorine) can be spritzed onto the evaporator with the fan running to get at stuff that might be growing in there.. Spritz some in the pan as well.. That stuff is pretty much the same that commercial coil cleaners use to get rid of mold.. There is some stuff available at auto parts places that is specifically made to kill mold in car air conditioners too.. Good Luck with it!

 

[Douglast]

febreeze if your stuck

 

[Hermit Scott]

Ozone generators can deteriorate your seat cushions and seals on your engine. I was advised by a moderator on this site not to use one on my boat.

 

[svenusa]

On cars, they switch on the air blower motor, and empty a can of lysol through the intake.. Just dont breath it in !! its a temporary fix though, the mold will come back next year - AC systems have a lot of moist dark areas !! Ozone generator works too, but you have to seal up the whole system tightly and let it recirculate for some time.. Again, its a temporary fix.

 

[RichH]

Molds and bacteria that grow in AC units can be VERY dangerous - think of Legionella (legionaire's disease) !!!

Best is to clean the coils and the drip pan with a CAUSTIC ... as it will dissolve the microorganisms and the 'remaining' caustic will prevent/retard future growth. A good caustic is a sodium silcate based detergent such as "tuff-enuff"... or plain old fashioned LYE SOAP will do. You may want to better 'incline' the drip pan so that it drains more completely and doesnt leave a 'puddle' of water .... you want it to drain completely.

If you have a moldy/mildewed AC drip pan ... then you can be sure that the rest of the hidden/dark/moist/unacessable parts of the boat are 'filthy' with mold (including the inside of your water tank and its vent). :-O
If the ducts are infected, then you must clean them by the 'wet method': spray in clorox, let soak and then scrub with a large 'bottle brush' etc. Cleaning any mold/ mildew while its 'dry' is a sure way to spread the deposited spores; and, the spores are more dangerous/toxic than the 'filaments'.

To keep mildew/fungus, etc. growth under control when not on the boat for long term ... you can (in states that have sane eco-statutes) get some paraformaldehyde crystals, put some in a metal dish, etc. and let the crystals sublime into the air in the boat. ParaF can be dangerous to human lung tissue, etc. so you need to open and air out the boat completely before going below. A common 'less lethal' mildew/mold/fungal control agent is "MildewGaz" (West Marine stuff).

Ozone will eventually attack and destroy all of the 'rubber' components on the boat: foam cushions, engine oil seals, wiring jackets, carpet backing, portlight hatch and window gaskets, weather/water proof touch pad/button membranes inside marine instruments and radios, etc. etc. etc. .... 'nuff said.

 

[Dan Johnson]

Having been in the HVAC remediation business...

RichH's comments about ozone are absolutely correct. We used a commercial medium sized ozone generator to "de-smell" motel rooms from smoking, but its use was for only a couple of hours in any one room. You had to run in to turn it off, run out, then wait for the level to subside. The "free" oxygen atom in the O3 generated grabs onto carbon atoms, leading to the deterioration of rubber and other things.

For the A/C coils and condensate tray there are two kinds of coil cleaner available from any HVAC commercial distributor (or a Grainger, etc.). One is mildly caustic and the other is not. It's far safer to use the one that isn't if you don't have any training in the use of caustic materials.