November 2004 Low Hanging Fruit Low Cost Energy Efficiency Opportunities in Cleanrooms

Free Cooling

Psychrometric Chart for San Jose 3,200 Hours Minimum

Free Cooling Configuration #2 - Series PCW Only

An Innovative Layout Possibility Dual Temperature Chilled Water Plant

Pumping Problems

Current Primary - Secondary Pumping

VFD Chillers

Lower Chiller Condenser Water Temperatures

Use Variable Speed Drives n Good for fans, even better for pumps, which are typically controlled and balanced by throttling

Remove Booster Pumps and close bypasses

Close 3-way Valves n B8 has a highly variable load due to air washer capacity, yet a constant flow

Aim for Highest Possible CHW Delta T

Exhaust Optimization Exhaust Reduction Amount Annual Electricity Savings (kWh) Annual Gas Savings (Therms) Annual Energy Cost Savings ($) 5,000 cfm223,40024,350$20,800 10,000 cfm440,00048,700$41,200 20,000 cfm854,00097,400$81,300 n Tool exhaust can be optimized via tracer gas or other accepted test methods n In most cases tool exhaust can be reduced 10 – 50% n Fume containment testing required for optimization also verifies worker safety n Case Study Savings Opportunity:

When replacing broken or worn out equipment Select the most efficient option n Efficiency often has little relationship to cost of equipment n E.G n Pumps n Electric Motors n Fans n etc.

Variable Speed Drive Compressors and waste heat regen dryers n VSD Compressors address the cycling problem

Commissioning / Retrocommissioning n Retrocommission - on a regular basis commission key components of system n E.G. - Develop standard tests for key control loops

Effect - Supply Air Temperature is Deficient Design Supply Air Temp is 55 deg F with no SAT reset

Cause Chilled Water Temperatures

Commission to avoid cycling

Control Optimization

THANK YOU! Rumsey Engineers, Inc. 99 Linden Street Oakland, CA (510)