fiberglass shredding problems

[Guest guest]

I've worked on about a dozen fiberglass issues in schools over the past three years. In all but two cases, the primary source was the acoustical tiles. As the HVAC system kicks on and off, pressure differentials occur on each side of the tiles causing movement of the tiles. This chafing against the T-bar holding it in place causes particles of fiberglass to come free and enter the room below.

In several cases, we replaced the acoustical tile with plastic tiles. In others, we clipped the tiles in place so they did not move when the HVAC system "burped." The clips worked fairly well but you have to start at one end of the room and work your way to the other. The last tile will remain unclipped. In most rooms we determined which tile would remain unclipped (one that gives you the best access to the overhead) before we started. As you might imagine, this can be labor intensive.

We took particle counts and tape lifts for particle characterization before and after clipping the tiles. After clipping, we wiped down the room before sampling. The counts were taken over a period of 48 hours for both conditions. The tape lifts were taken in both conditions after the 48 hours of HVAC operations. The result was a significant reduction (by about 90%) of all particulates and in many samples the fiberglass was non-existent.

What this verified in our minds was that having good filters on the HVAC system is only part of the "particulate elimination war." Securing or eliminating the acoustical tiles may be an even more important step.

Herein lays your lesson for the day from Miles Athey "The Glass Wizard of Eastern Washington"

Miles