Air Filter System EOC Tour Main Outside the EOC Front Entry Dormitory Communications Operations Room Radef/Operations Mayor's Office Men's Restroom Mechanical Room Air Filter System Kitchen Hallway Outside Entrance Back to Shelter Tours Main Back to Civil Defense Museum Main		Air Intake and Filtering System-Intake Chamber This photo was taken looking into the air intake chamber from door of the air filter chamber. The ladder in the wall leads up to the escape hatch. The other round hole to the left in the ceiling is the air duct that leads up to the air intake anti-blast valve. To see a close-up looking up into the intake anti-blast valve click here. Anti-Blast Valve Close-Up. Air coming into the shelter enters this chamber first before passing throught the first stage air filters. The first stage air filters are immediately to the left in this photo. You can just make out the corner of the first stage filter box in the upper left corner of this photo. First Stage Air Filters These are the first stage air filters. This photo was taken from inside the air filter room. The filters are next to the door leading into the air intake chamber. The above photo was taken looking through the small door seen to the right in this photo. The air intake chamber is full of old files boxes piled about 3 feet deep as you can see through the opening. The air intake chamber is actually a single room divided in half with a metal wall unit containing the first stage air filters. The largest particles are captured in the first stage filters. First Stage Air Inlet Duct This photo was taken looking up above the door into the filter room from the mechanical room. The grey frame of the door to the mechanical room is visible at the bottom right of the photo. The opening in the wall is the duct into the mechanical room leading to the generator air inlets and the first stage air blower unit. Here is the same duct seen in the above photo from the other side of the wall in the mechanical room. The top of the door to the air filter room can be seen at the right lower corner of the photo. The small shelf on the wall next to the door is the mount for the first stage air filter intake blower. With this blower operating air is only drawn through the first stage filters and delivered to the air conditioning system. Second Stage Air Filters This photo was taken inside the air filter room facing away from the first stage filters. It's almost impossible to get a good photo due to the small size of the room. The upper corner of the door to the mechanical room is just visible to the immediate upper left in the photo. The dark square in the wall is the inlet into the upper second stage air filter. There is more stuff piled in this room too. The lower second stage filter inlet is the same as the upper filter inlet. The access hatch to the small second stage filter room is just out of the photo to the lower left. Here is what you see when you look through the small hatch that leads into the second stage filter room. You can see the 2 secondary air filters to the right in the photo. The galvanized metal wall that divides the air system chamber in half is visible to the right of the water barrels. This room is about 5 feet by 5 feet square. I can't figure out why these water barrels were stashed back in this room. They were empty and most were in pretty good condition. There would have been no use for them originally because the shelter got it's water supply from well water. Maybe they were stored in here for use as toilets in case the sewer system failed. Here is a close up look at the label on the side of one of the air filters. Notice the "Gas Particulate" designation on the label. This photo shows the top of the second stage air filter room. Upper second stage filter is on the right of the photo. The opening, with the light shining on it, above the explosion proof light fixture is the secondary air inlet duct which leads to the secondary air blower. The second stage air duct passes through the wall to this second stage air blower. The duct behind the blower is the same duct seen in the above photo. This unit is quite a bit larger than the first stage blower. Maybe it is larger due to the greater resistance of air flow through the second stage air filters. The first stage blower bracket can be seen in the upper right corner of the photo. Both of these blowers duct into the air conditioner. I didn't think to look how they switched between the two different filtering stages. I don't know if there was a damper in the ducting to switch between ducts or if the blowers were just run alternately respective of which filtering stage was to be used. Go to the Kitchen Back to the Mechanical Room Back to EOC Main