INTER-OFFICE CORRESPONDENCE    
    
    

To:	All members of Computing Services in Cyert Hall     Len Brush Jaime Carbonell
From:	William Y. Arms
Date:	September 16, 1994
Subject:	Black particles
cc:	Patrick Keating, Ron Carter

In May, I wrote to you about the efforts to fix the problems of black particles that fall through the cooling vents in Cyert Hall. This is to bring you up to date with the progress that has been made in the past few months. 

Background 

The particles are generally agreed to be soot. Small specs come from the outside, get past the filters in the main ducts and accumulate into large particles on the ceiling vents. Eventually these particles get loose and fall out. 

Work to date 

Over the past few months, Facilities Management has carried out two pieces of work. The first was to seal around the filters to make sure that all the air goes through them. The second was an experiment to replace the ceiling vents in four offices with new units. 

The experiment was partially successful. The four offices were selected as places where the black particles were particularly bad. Since the vents were changed they have been essentially clear. Unfortunately, however, dirt is already beginning to build up on these new vents. Too much soot is getting past the filters. Therefore, Facilities Management plans to carry out three parallel pieces of work. 

The next stage - filters 

In late September, Facilities Management will begin another experiment. They will replace the ventilation filters in part of Cyert Hall. The new filters are much finer than the old ones. It is expected that they will remove a much higher proportion of the soot, buth they may slightly reduce the fresh air flow. The objectives of the experiment is to see if there is any loss of fresh air and to measure how much soot gets through the new filters. 

The next stage - variable air vent 

A second experiment involves only one office, Cyert Hall 125. In this office, the overhead vent will be replaced by an entirely new type of vent. The aim of this experiment is to see if black particles accumulate on the new vent. 

The next stage - ceiling vents 

While we hope that different filters will greatly reduce the amount of soot that enters the building, a large amount is already in the ceiling vents. During the next couple of months, even before the effect of the new filters is known, Facilities Managment will replace the vents in offices that have severe problems with black particles. Attached to this memorandum is a survey from Ken Burner to identify the offices where the problems are worst. Other vents may be replaced later in the light of experience. 

Questions 

Ken Burner is the building manager for Cyert Hall. If you have any questions or problems with the building, you should contact Ken or me.