Lee – taken Illinois summer max temps as a criteria of outside air and dehumid to 49 deg F dewpoint and putting into every other shaft and exh at other shafts. The air travels 5km .  Total air volume is 20000 CFM. The 1mph is an historic number at FNAL. Comp to CERn. This sets the large dehumid on the surface. Don’t run this system for the beam tunnel when beam is on. No air in or out of beam tunnel during operation. Criteria are agreed upon for the dewpoint. Even for a CERN site. Reduce the cost by reducing the airflow requirement. Recirculate? How is this done with miles of tunnel? Use the beam tunnel? 3 things: radiation, cryo, escape. The tunnels were separated for these reasons. In a normal situation there would be a pressure difference. The service tunnel is not ODH zone. Will there be N2 used in the service tunnel? Skids makeup tank and waveguide pressurization. Where does the mile/hour come from . Osha 200 CFM/person 200CFM/brake horsepower diesel and another criteria for digging. One air change / 3 hours is pretty low compared to occupied buildings.  Does sealing the beam tunnel result in dry enough air. There are scattered dehumid in the beam tunnel. There are 2 schemes discussed: one cycle with the beam/service tunnel and indefinite recycle. OSHA standard for the storage of flammable and combustible liquids – 6/hour.  10CFR1926.152.B4Vi . release of rock related gas. Separate water sources – spilled water and ground water. These are small compared to the water in the surface air. (one dehumidifier in the beam tunnel every 3 RFun its – present model).why not extend this to the length of the tunnel? This is a 3rd model – using only one central.