CEDAR Detector Ventilation System Review F. Dragoni, G. Nitwinko, M. Alam EN-CV

Summary & Scope Locations Thermal Housing Analysis Technical solution: PID, Integration, Controls Planning Budget Risks

Required Air Flow: Theoretical Study Geometry shape used as Cross-Section SUMMER TOUT = 30degC Aerogel Max Heat Gains [W] 53.3 55.6 61.9 Min Airflow [m3/h] 1695 1767 1968 WINTER TOUT = 15degC Max Heat Losses [W] -37.6 -40.2 -47.5 1195 1276 1508 Selected air flow for each thermal housing: 2500 m3/h

Technical Solution Air flow: 2500 m3/h - 100% recirculation Extremely long cooling coils – 30 rows Laboratory chiller Water temp stability under all load conditions Simplifies controls – Can set temperature & pressure Water IN Temp = 23 degC Water OUT Temp = 24 degC Air OUT T = 23 degC Air IN T = 25.5 degC

PID Air Handling Unit Precision Chiller

Location & Physical Constraints Platform is preferable location for ventilation system CEDAR BEAM

Integration Air Handling Unit Return Ductwork Supply Ductwork Chiller

Controls Fixed fan speed to achieve 2500 m3/h Set circulating fluid Temperature + Pressure, i.e. the chiller internal controls keep stable circulating water temperature No active control. Monitoring only via WAGO CEDAR air inlet/intermediate/outlet Temp Chiller status + water supply Temp Water Flow rate Water Inlet/Outlet Temp Fan status + fan speed Filter/Strainers pressure switches Air average temperatures before/after cooling coils

Limitation due to fixed point functioning Water temperature is not adapted to seasons AHU CEDAR Set T = 23.0 °C Summer Air in Temp= 23.0-23.1 °C Winter Air in Temp= 22.9-23.0 °C Air flow rate reduces as filter clogs – Minimal impact due to 100% recirculation

Planning

Budget Based on received estimates and framework contractor’s unit prices Item Estimated Cost Possible Savings Air Handling Unit 12,700 CHF N/A Duct network, fittings and air-side sensors 18,950 CHF -1,650 CHF Pipework, fittings and water-side sensor 19,850 CHF -600 CHF Cooling system (Chiller) 10,000 CHF Electricity, ethernet and monitoring (WAGO) 10,400 CHF Design, documentation, testing 5,150 CHF - 250 CHF Items supplied by CERN (drainage extension) 2,800 CHF - 900 CHF External Transport (air handling unit, chiller) 2,000 CHF - 1,150 CHF Other supplies transport (5% value of supplies) 2,300 CHF - 150 CHF FSU (Draftsman, Work Supervisor) 4,000 CHF 10 %  Contingency 5,700 CHF Sub-Total 93,850 CHF 89,150 CHF EN-EL Power Supply 2,950 CHF Total 96,800 CHF 92,100 CHF Assumptions 1 concrete slab can be removed Concrete blocks can be drilled for supports EUR/CHF = 1.18 EN-EA responsible for design, supply and install of steel frame/mountings where AHU will sit Minor modification to handrail are allowed – cost not included CERN Internal Transport is free Note design costs include: detail design of ductwork, pipework and cable runs design of electrical cabinet

Possible/Potential savings Ask CERN transport to organise transport of AHU from factory to Previssin  Possible saving 1150 CHF Swap supply and return ducts – supply ductwork is more expensive due to thickness insulation  Possible saving 650CHF. Only 1 set of flexible joints  Possible saving 1,000CHF. Buy flow meter transducer/switch from SMC  Potential saving 600 CHF. Possible saving on drainage cost  Potential saving 900 CHF.

Conceivable not likely Risks # Risk Impact P C Mitigation 1 EUR/CHF exchange rate – approx. 85% supplies are paid in EUR Cost increase in CHF terms 5% increase in EUR/CHF  4k CHF more needed Likely 20%<P<50% Cost: 4-5 kCHF No mitigation 2 Late delivery of AHU Delay to project completion Conceivable not likely 10%<P<20% Delay 1 week 1. Place order asap 2. Put pressure on manufacturer 3 Drainage point cannot be moved Possible delays - added cost: additional supply, pump and piping. Delay: 3-5 kCHF 1. Start civil study asap 4 Handrail needs major modifications Possible delays and additional cost 1. Start frame integration with platform asap

Q&A?

Challenge Design a ventilation system: To have a sufficient air flow to maintain longitudinal temperature stability inside 2 CEDAR Capable of supply air at a set temperature ±0.1K

Summer - Heat Loads Ambient Temp = 30 degC Set Temp = 23degC Max Q = 70 W Ambient Temp = 30 degC Set Temp = 23degC Total Q = 2.0 kW 23.1 C Max Q = 68 W 25.5 C 23.0 C 23.2 C Max Q = 20 W Running Q = 0.6kW Max Q = 1.5 kW 23.5 C Max Q = 110 W 23.3 C Max Q = 120 W 23.6 C Max Q = 70 W

Winter - Heat Losses Ambient Temp = 15 degC Set Temp = 23degC Max Q = 70 W Ambient Temp = 15 degC Set Temp = 23degC Total Q excluding motor = -0.5 kW Including motor = 0.1 kW 22.9 C Max Q = 68 kW 23.0 C 22.8 C Max Q = 20 W Running Q = 0.6kW Max Q = 1.5 kW 22.5 C Max Q = 110 kW 22.7 C Max Q = -140 kW Max Q = 70 W

Chiller selection Packaged precision chiller of smaller sizes do not allow to achieve required flow rate 50l/min @ required pressure 0.3M No Inverter on pump – less flexibility in system 5kW Chiller Pump Curve 10.5kW Chiller Pump Curve

Modifications to Handrail

Removal of concrete slab Slab to be removed

Technical Solution CEDAR #1 CEDAR #2 AHU 2500 m3/h Chiller