White Powder coming out of Ducts??

[edspace]

I own a commercial office space, a small one, in North GA. It is a one ton unit. I had some white powder coming from the evaporator coil through the ducts and onto the desks and floors. I had the entire unit replaced and 1 year later it came back. I have checked all the obvious things. I have replaced duct work, replaced filters, checked returns, in addition to replacing the air handler and A coil. My HVAC guy has asked numerous experts in the field including a Goodman tech without any help. At this point we are trying to clean the coil and hope it doesn't come back. So far those attempts have yet to be successful. Ever seen this? Any idea what it is? It is a white powder and not building materials or paper. It forms on the coil the office space is very clean an nothing to my knowledge is being sucked into the unit.

[Stamas]

Please do not make duplicate threads.

[edspace]

sorry... new to all this. I thought I was approaching 2 different groups. The residential and commercial forums. I defiantly don't want to tick off the people I'm asking advise from. now I don't know how to delete my second post

[martin&sonsa/c]

man you have an awesome a/c system its actually blowing out snow flakes LOL!!!!

[lynn comstock]

Normal oxidation of aluminum creates an invisible protective coating on the aluminum.

Check the white corrosion of aluminum info at http://1st-coating.com/corrosion_alloys.htm.

Chemical reactions to air contaminants may be causing this. It would be good to check the equipment grounding circuit because electrical charges on the metal surface accelerate corrosion processes.

[edspace]

You seem to have a high level of knowledge on this. Have you ever seen or heard of this problem? I have yet to find someone that has experienced this or found a solution. I have had numerous veteran contractors come look at it and none can give me an explanation. Really puzzling. I will have my HVAC guy check to see if it is grounded properly. Thanks for your input.

[lynn comstock]

A common source of chemical contaminants is cleaning products. If you are using a commercial cleaning service, their products are often "stronger" than products used in homes because they save time. Pay paricular attention to floor cleaning products.

[FL.HVAC]

Normal oxidation of aluminum creates an invisible protective coating on the aluminum.

Check the white corrosion of aluminum info at http://1st-coating.com/corrosion_alloys.htm.

Chemical reactions to air contaminants may be causing this. It would be good to check the equipment grounding circuit because electrical charges on the metal surface accelerate corrosion processes.

That was my thought.
OR!
Anthrax!!!!

(JK)

[edspace]

We do not have a professional cleaning service and use normal household cleaning supplies. The only thing I can think of out of the ordinary are the essential oils that a lady in my office often burns with a candle. Do you think those oils could be causing the problem?

[lynn comstock]

...Do you think those oils could be causing the problem?

Who knows? Something is going on. For all I know contamination may be from outside. Air conditioning equipment installed near the ocean corrodes badly because of sea salt in the air from ocean water spray. (As an example that is well documented.)

The other possibility is the electrical grounding of the equipment isn't working properly, and that needs to be checked out.

[edspace]

I have tried everything.....Time to get OSHA involved.

[lynn comstock]

Collect some powder and have it chemically analyzed if you are serious. With mass spectrometry it doesn't take much of a sample.
http://en.wikipedia.org/wiki/Mass_spectrometry

[edspace]

we were thinking the same thing, ok I have collected a sample and am ready to send it off to EMSL they said it would be $550 - $700 for tests to discover what this stuff is. Any other suggestions? of places to get it tested. Seems expensive.

I did find this of interest. This website talks about a known problem with Ford cars Ford only says it "may be caused by flux utilization of the evaporator coil"
http://www.ford-white-dust.com/