All,
I was cleaning my Air handler coil this weekend and was disguted by the filth that came out of it! I bought the house about three years ago. The unit is a 26 year old ground source heat pump. I sprayed some foaming coil cleaner on it and hosed it off. That didn't seem that bad. It was moldy and some light solids came off it. Then, I blasted the coil with compressed air...... thats when the Stuff hit the fan, so to speak. There was all sorts of different color crap coming off the coil that was brown and black. Parts were flat and others round and quickly coated everything in the area; floor, walls, water heater, even ME! Has anyone experienced anything like this? Am I at any health risk? Is it common for coils to load up with this stuff?
Secondly, air flow was noticably improved after the cleaning. the coil was actually clogged with organics, of some sort?

 

I have seen it before, they make an acid based foaming cleaner for industrial maintenance use that does a good job of lifting the crude out of the coils but a mid-power pressure washer spraying the crude out from the back side of the coils is the better way of cleaning them. Too much pressure and you will bend the fins and restrict even more airflow.

A better grade filter with good a maintenance program is the best solution once there clean. Reduced air flow will result in higher head pressure and higher operating costs.

 

Yeah, it hasn't been cleaned in many many moons. Those are just different kinds of mold growing on it. Give it a couple of more cleanings with the acid. Instead of compressed air, get a long brislted nylon brush,(I get ours in the parts store, it's just a large scrub brush for rims), then load the coil up with acid,and scrub away, both sides. Don't leave the acid on there for more than a few minutes(rinse well with water, this neutralizes the acid) as it will eat the alluminum and make the coil into scrap, not to mention give you a good blast of refrigerant in the face. (BTW, IF your not doing it already, please use some eye protection, some of the more effective coil cleaners like Hurri-clean brand will really do some serious damage.)

After you get the solid stuff out, wash it down with water until the coil looks clean with a flashlight thru it, then dilute (50%) some bleach into a pump spray bottle, soak the coil and let it stand for 10 min's or so, then wash it out with a lot of water, and do it a second time. This will kill anything you missed, and wash out the condensate drain at the same time. Don't turn the heat on for an hour or so, until the coil dries, and odor of bleach goes away, or open some windows and set the fan switch on the t-stat to ON for a few minutes.

On a side note, if there was that much bac on the coil, then I would be looking to service the ductwork as soon as possible.

I've personally seen whole households get extremely sick from bad fungal growth on evaporator coils and infected ductwork. And yes, these kinds of things can indeed be life threatening to a sensitive individual.

 

I worked for my dad in air conditioning for years and he still does it, I always just cleaned out the A-coil with water.
Also, most of that fungal stuff is a gimmick so some companys can get you too pay them mucho bucks and make a huge profit cause they don't do much work at all.

 

If you leave the fan control in the "on" position all the time to keep air flowing in the home the water it condenses on the coil (in a/c mode) cannot completely run down the fins and out the drain, this causes mold along with the general dirt/dust in the system to collect there. Need to wash inside/outside coils no less then twice a year or maybe once a year depending on location.