# Presentation: 406380

## Slide 1

## Energy Benchmarks

- Goal:
-     Identify Energy Efficiency Opportunities in Cleanrooms Through Comparison of Benchmark Data

## Cleanroom Energy Benchmarking

**Cleanroom Energy Benchmarking**

## Why Benchmark High-tech Buildings?

-   From PG&E’s perspective:
- 	PG&E saw that the market was large and growing.  In California:
**9400 GWH in 1997 (all high tech buildings)**
**4.2 million sq. ft. of operating cleanrooms **
**Semiconductor and Biotech exhibited high growth****  **

## Why Benchmark Cleanrooms?

-     Owners perspective:
- 	Cleanroom owners and facility engineers saw an opportunity to determine their energy end use, compare their efficiency to others, and potentially find efficiency improvement  opportunities or uncover operational problems.

## Why Benchmark Cleanrooms?

-   From a public goods perspective:
-    Under-served Market – Emphasis on product 	rather than cleanroom
-    Explore some Myths
-  Energy is not a controllable 	expense
-  We already considered efficiency
-  Of course its efficient, we just built it.
-   California would like to keep high-tech 	companies in the state
-   And the usual “save the planet” reasons

## What we hope to accomplish

- Identify energy efficiency opportunities
- Integrate current best practices into operation and future design
- Research new approaches and technologies
- Reduce electrical demand to improve reliability and room for growth
- Apply lessons learned in California cleanrooms in other regions and other building types

## Benchmarking Process

- General plan – informs participants
- Enlist Benchmarking participants
- Site specific plan developed
- On-site measurement and data collection
- Draft site report
- Final participant report and anonymous version
- Data and results entered in data base and summarized on web site

## Metrics

- Ability to compare   	performance regardless of 		process
- Focus on system efficiency rather than production efficiency

## Cleanroom HVAC metrics

- Recirculation air system – cfm/kW
- Make-up air system – cfm/kW
- Exhaust system efficiency – cfm/kW
- Cleanroom air changes – ACH/hr
- Air velocity in cleanroom - ft/sec

## Central Plant metrics

- Chiller efficiency – kW/ton
- Cooling tower efficiency – kW/ton
- Condenser water pump efficiency – kW/ton
- Chilled water pump efficiency – kW/ton

## Vision - an Energy BenchmarkData Base 

- Anonymous reporting
- Comparison of similar class systems
- Comparison of components
- Comparison of overall facility
- No production metrics
- Sufficient data to identify best practices

## Cleanroom Benchmarking

**Some Results and observations to date**

## Energy End Use

**Energy End Use**

## Energy End Use

## Process Related Efficiency Issues

- Energy intensity varies greatly depending upon the process in the room
- Estimating process (heat) loads during design is a challenge so HVAC systems are often oversized
- HVAC equipment sized and controlled appropriately operates more efficiently
- Benchmark data can help determine realistic design loads to integrate into future projects for similar processes
- It is difficult to compare process energy efficiency unless nearly identical processes are occurring

## Process Loads

## Energy Intensive systems

**	****Recirculation of air in cleanrooms**

**Notes:**
Guide will be organized around these major pieces of the energy pie.

## Recirculation Air Comparison

## Recirculation Systems

**Recirculation Systems**
**Design vs. Measured**

-  Why are Design Efficiencies less than  Measured Efficiencies?
-  Design efficiency is generally understated because larger power consumption (kW) is generally assumed.  (nameplate vs. actual)

## Benchmarks as Design Criteria

- Idea!  As a building owner,
- Why not specify a system efficiency?

## Recirculation Air Comparison

- System Performance Target

## What is the cost impact?

## Fan-Filter Standardized Reporting	

- LBNL and the Industrial Technology Research Institute (ITRI) in Taiwan are advocating a standard test procedure for fan-filter units
- The Air Movement and Control Association (AMCA) is organizing member companies to develop such a standard

## Make-up Air Comparison

**Make-up Air Comparison**

## Make-up Air System Considerations

**Efficiency is influenced by:**

- Right sizing exhaust and pressurization
- Resistance of make-up air path
-   Adjacency of air handler(s)
-   Air handler face velocity
-   Duct sizing and layout
- Fan and motor efficiency
- VFD controls

## Make-up Air

**Make-up Air**
** ****Design vs. Measured**

## Why is make-up air system efficiency lower?

- Retrofitted systems with less than optimal configurations
- High face velocity air handlers (due to space constraints or just inefficient design)
- Older less efficient equipment (motors, fans)
- Resistance due to heating and cooling coils, filters, etc.
- Duct sizing and layout

## Air-Change Rate Comparison

**Air-Change Rate Comparison**

## Air Change and Velocity Observations

- Wide variation
- All processes had acceptable yields (so why do some get by with less airflow?)
- All cleanrooms were “certified”
- Some velocities exceeded (and some were below) IEST recommended ranges
- IEST provides recommendations based upon historical adequacy – not science based
- Air velocity reduction and ceiling filter coverage are efficiency improvement opportunities

## Chilled Water Systems Comparison

**Chilled Water Systems Comparison**

## Chiller Comparison

**Chiller Comparison**

## Chilled Water System Observations

- Surprise! Name plate chiller efficiency is different than measured
- Pumping energy can be significant – over pumping sometimes occurs
- Chiller performance dominates
- Water Cooled chillers are more efficient

- Wide variation in overall efficiency

## Chilled Water System Resources

- 	Existing efficiency information for chilled water plants is under-utilized.

## Chilled Water System 

- PG&E’s   CoolTools
- 	http://www.hvacexchange.com/cooltools/

## Non-energy benefits of Benchmarking

- Operational problems revealed
- Controls
- Setpoints
- Maintenance needs identified
- Leaks
- Motors, pumps, Fans
- Filters
- Chillers, boilers, etc.
- Safety issues uncovered
- Hazardous air flow

## Slide 38

## New Construction or RetrofitEfficiency Opportunities 

- Air Change Rate Reduction
- Temperature Set Point
- Chilled Water System Pumping
- Better Use of Cooling Towers
- Chilled Water Temperature

## More Efficiency Opportunities 

- Control Problems
- Filter Coverage and Type of Filter
- Removal of Pre-filters
- Humidification
- Minimize reheat
- Lighting controls
- Pressurization losses
- Exhaust Reduction

## Efficiency Considerations during Programming 

- 	LBNL Cleanroom Programming Guide Provides a Way for Owners and Designers to Explore Efficient Options During the Early Stages of a Project.
- 	 http://ateam.lbl.gov/cleanroom/guide/
- 	 ProgrammingGuide-LBNL49223.pdf

## Benchmarking Can Be Used to Establish Efficiency Goals	

- Energy Budget
**Total facility**
**End use**
- Integrate Efficiency Targets as Design Requirements for Key Systems and Components
**Cfm/KW**
**KW/ton**
**System resistance – i.e. Pressure drop**
**Face velocities**

## Benchmarking highlights some important issues

- Designing and operating at higher cleanliness than is needed does not improve yield, but it does use more energy
- Air change rates can be reduced in many cases
- Chilled water pumping may be excessive
- Flow resistance has a big effect
- 	 on life cycle cost
- Overcooling and reheating
- 	often represents opportunity

## My Recommendation

-    	Designers (and constructors) will provide what their customers ask for.
- 	If you are an owner and want efficient systems, ask for them.
- 	If you are a designer, show owners the benefits of an efficient design – often lower first cost or early payback.  Huge benefits over the life cycle.