License # 719286
Steve Huff
Clean Room Odor

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Often the simplest route is the most effective

A tech manufacturing business was having a big problem with personnel periodically having to evacuate a clean room due to an odor. This had gone on for several weeks; costing many thousands of dollars in lost production. There did not seem to be any rhyme or reason to it. The odor just suddenly appeared and all personnel went outside. Experts of various kinds were brought in to solve the problem all to no avail, but costing more thousands of dollars.

This was fairly early in my career so I was working directly with George Machado. We arrived early in the afternoon and began asking questions about the odor, the personnel and the clean room itself. There was talk about doing air sampling in the clean room, but one piece of information we were able to get was that the room had to be maintained at a specific humidity in order to reduce the possibility of static electricity. We asked how they were able to do that and learned that they have a humidifier inside the HVAC system that triggers when the humidity falls below a certain level. So at that point, we asked to inspect the HVAC system.


This was a large system with very large ducts so we were able to stand up inside the supply duct that served the clean room. After we got there, we asked to have the humidifier activated. Within minutes of this happening, the clean room began to be evacuated. The odor was coming from the humidifier so the odor appeared whenever the humidifier came on. Since it was tied only to the humidity level dropping, there did not appear to be any pattern to it. But the humidifier was needed to maintain the all-important humidity level. So what could they do?

Upon additional questioning, we found that the water for the humidifier was supplied by the boiler. We asked to see any records about the maintenance of the boiler. We had already discovered the approximate time period that the odor appeared so we looked for any changes that had occurred just prior to that. We found that they had changed an additive that was used to help prevent scaling inside the boiler. We recommended that they change back to the original formula. That was done almost immediately and we later got a report that they were no longer having the odor problem.

A problem that had been going on for several weeks costing thousands of dollars in production loss and costs to investigate, we were able to solve in less than 1 1/2 hours. The moral of this story is to ask questions and always look first for the most direct and simplest cause for a solution.