November 2004

1

Top Ten Approaches to Lowering Fan Energy in
Cleanrooms

• November 2004
• .

2
First the Basics

• Fan Power CFM x Pressure Drop (in inches)
  6345 x Fan Eff x Motor Eff

3
Ten Use Best-in-class Motors
Use Motor Master Software
4
Nine Use Efficient Fans
5
Eight Use Variable Speed Drives

• Thank you cube law!
• Often fan systems are turned down after startup.
  This is done most efficiently and most simply
  with VSDs.

6
Seven Select a Low Pressure Drop System

• Recirculation Air Handling Systems in Cleanrooms
• Pressurized Plenum
• Ducted Hepa
• Fan Filter Units

7
Six Use Low Face Velocity Air Handlers
8
Five Use Demand Controlled FiltrationTimeclock,
occupancy sensor or particle counter
40 setback 70 energy savings
9
Four Select Most Efficient FFUs
FFU Performance is a function of - Airflow
(CFM) NOT Velocity - Filter Efficiency -
External Static
10
Three Exhaust Optimization

• 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??

Wet Bench - 574 to 254 scfm
Vertical Furnace - 628 to 474 scfm
Courtesy of Northwest Energy Efficiency Alliance
Website (www.nwalliance.org)
11
Two- Use Mini Environments

• Can be coupled with reduction in overall
  cleanliness rating
• Wafertech

12
One - Select Appropriate Air Change Rate
13
Results when implemented as a system
14
Successes Air System Optimization
15
Air System Optimization 75 Savings
16
To Summarize.

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