Read the gas code!!! A 90% 1 pipe flue should be well away from any openings in the structure where fumes could be sucked in. Hmmm, these 2 exhausts are blowing right at the combustion air inlet to the equipment room. Guess no one in that building has ever read the venting instructions from NFPA54. NFPA is National Fire Prevention Association. The building? A FIRE STATION!