dark gray slime on evap coils
ok guys i hope you can help. i was called to look at two 5 ton evaps (one luxaire one carrier) that have slime on them.
these a/cs take care of a paint lab at a diamond vogel paint factory. last summer the coils were slimed up bad. i removed them and pressure washed them and cleaned with a coil cleaner. this summer it is the same thing. the coils basically become completely blocked and the lab temp starts climbing.
they told me that the sinks will get the same kind of slime in them over the weekend when they dont run any water.
what i want to know is what can i do to fix this. i dont want to remove these coils every summer to wash them. what are my options? has anybody seen this? is their a specific chemical in the paint that is causing this???
i can get additional info if needed.
nobody has ever seen this?????
Since no one else replied, here are a few questions that may help work through the problem.
Originally Posted by jeep6275
The labs have no idea what it could be even if they get it in the sink? Is it even biological? Could it be particulates in suspension in the air that when mixed with water on the coil become viscous to make the "slime", or deposit from the air into the sink during the weekend? What kind of air filtration is in place? My bet is that it's something they use in their "recipes" that makes a lot of dust when used.
they dont seem to have any idea exactly what it is from. just that it is something from their paint. it started about 3 yrs ago.
i think you are on the right track i agree with your thoughts (something mixing with the condensation to form the slime). as far as filtration they just buy the 5 dollar pleated filters.
i have no experience with the lights? would they help?
UV lights won't help if it's not biological.
Originally Posted by jeep6275
It must be very fine dust. Without knowing the size of the dust particles it's hard to make a MERV recommendation. Could the HVAC system handle the static pressure caused by some MERV 11 filters? If so I'd buy and install new MERV 11 filters just for a test, and come back after a while to see if they are catching more dust. I wonder, if you were to remove the media from a spent filter and soak it in a little bit of water, if the slime would appear. If so then upgrading the filters to a higher MERV rating sounds warranted (11 if the systems can handle it) to catch more of it before it gets to the coil, and change the filters more often. That's probably the cheapest and most efficient solution, apart from controlling the source.
I find it somewhat hard to believe that they have absolutely no idea of what they did 3 years ago (new ingredient, new process, new machines) that could cause this...
If you take their paint ingredients and mix them one by one with a bit of water, can you get a similar slime to appear?
thank you this is exactly what i am looking for. i will give this a try and get back to you.