November Top Ten Approaches to Lowering Fan Energy in Cleanrooms

Rumsey Engineers, Inc. First the Basics n Fan Power = CFM x Pressure Drop (in inches) 6345 x Fan Eff x Motor Eff

Rumsey Engineers, Inc. Ten – Use Best-in-class Motors Use Motor Master Software

Rumsey Engineers, Inc. Nine – Use Efficient Fans

Rumsey Engineers, Inc. Eight – Use Variable Speed Drives n Thank you cube law! n Often fan systems are turned down after startup. This is done most efficiently and most simply with VSDs.

Rumsey Engineers, Inc. Seven – Select a Low Pressure Drop System n Recirculation Air Handling Systems in Cleanrooms n Pressurized Plenum n Ducted Hepa n Fan Filter Units

Rumsey Engineers, Inc. Six – Use Low Face Velocity Air Handlers

Rumsey Engineers, Inc. Five – Use Demand Controlled Filtration Timeclock, occupancy sensor or particle counter 40% setback = 70% energy savings

Rumsey Engineers, Inc. Four – Select Most Efficient FFUs FFU Performance is a function of: - Airflow (CFM) – NOT Velocity - Filter Efficiency - External Static

Rumsey Engineers, Inc. Three – Exhaust Optimization Courtesy of Northwest Energy Efficiency Alliance Website ( Wet Bench to 254 scfm Vertical Furnace to 474 scfm Turn off canopy and snorkel when not in use Lower Exhaust Air Change Rates when unoccupied Minimum Air Change Rates – 12 ACH, 10 ACH, 8 ACH, 6 ACH??

Rumsey Engineers, Inc. Two- Use Mini Environments n Can be coupled with reduction in overall cleanliness rating n Wafertech

Rumsey Engineers, Inc. One - Select Appropriate Air Change Rate

Results when implemented as a system

Rumsey Engineers, Inc. Successes – Air System Optimization

Rumsey Engineers, Inc. Air System Optimization – 75% Savings

Rumsey Engineers, Inc. To Summarize…. n 10 – Use best in class motors n 9 – Use efficient fans n 8 – Use VSDs n 7 – Select a low pressure drop system n 6 – Use low face velocity air handlers n 5 – Use demand controlled ventilation – Timeclock or particle sensor n 4 – Select most efficient FFUs n 3 – Exhaust Optimization n 2 - Use Mini Environments n 1 – Select appropriate air change rate