21st Century Cooling for Dry ClimatesFor the Napa Valley Wine Technical Group

Dick Bourne, WCEC Assoc. Director

January 22, 2009

Electricity: Cooling is the Culprit

• July peak demand is 35% above January

• Cooling causes electricity peaks

7% Load Factor for Residential

22% Load Factor for Non-Residential

• Cooling peak reducers - best new peaking plants

Western Climates: Issues = Opportunities• Large Diurnal Temperature Swings

Issue – Poor Load Factor

Opportunity – Thermal Storage

Warm air

HOT air

Warm air

HOT air

• Low Outdoor Humidity

Issue – Non-Optimized Equipment Opportunity – Evaporation for Cooling, Radiant Cooling

WCEC: Who We Are• Part of the Energy Efficiency

Center at University of California, Davis

• Launched April 2007

• Current staff: Mark Modera, Director

Dick Bourne, Associate Director

Marshall Hunt, Programs Director

Kristin Heinemeier, Senior Engineer

Seven Mechanical Engineering Students

WCEC: Who We Are• Affiliate Structure

Utilities

• PG&E, SCE, SMUD, SEMPRA

Manufacturers

• Delphi, Ice Energy, ICI, Lennox, Munters, NovaTorque, Seeley Intl., Speakman, Thermal Flow, Trane, Viega, VRTX

Contracting/Design Firms

• Beutler, Davis Energy Group, Timmons Design Engineers

State Agencies

• CEC, DGS

Retailers

• Wal-Mart, Target

WCEC Goals

• By 2030, reduce cooling demand and energy use from 2007 baseline New buildings

• Zero cooling peak demand

• 50% reduction in cooling energy use

Existing buildings

• 50% reduction in cooling peak demand

• 25% reduction in cooling energy use

What We Do• Publicize cooling technologies optimized for hot, dry west

Support affiliate alliances and partnerships

Address market impediments (e.g. codes and standards)

Help bridge commercialization “valley of death”

Emerging technology demonstrations

• Research and development Identify, conduct and support key R&D

• Technology development

• Laboratory and field testing

• Modeling and analysis

• Outreach activities Catalog of energy-efficient cooling systems

Website, newsletters, presentations, publications

Education – university and professional

Current WCEC Activities• Funded Projects

CEC - PIER Advanced Cooling Support Program CIEE – State-building technology demonstrations (SDSU and UCSD lab

sash project) BERG – Improving the Cost Effectiveness of Radiant Floor Cooling

Systems SEMPRA- Energy Performance of Hotel Controls (with CLTC) SMUD –Hybrid OASys Field Test BERG at LBNL – Exhaust Duct Leakage Diagnosis in Multi-Family

Buildings EPRI – SEER Review, Status and Recommendations LANEY COLLEGE/NSF – HVAC training SCE

• Water Management for Indirect and Indirect-Direct Evaporative Air Conditioning

• Water Use by AquaChill evaporative condenser

Current WCEC Activities

• Projects in Process CEC – Three-Year WCEC Research Support DOE – Development of lab tests for annual savings predictions SEMPRA/PG&E/SCE – Statewide Initiatives (Evaporative Cooling,

Hot Dry AC, Fault Detection/Diagnostics)

• Newly-Funded PIER Projects Radiant Cooling for Residences Non-Residential Fault Detection Diagnostics

Current WCEC Activities

• Current Key Activities Western Cooling Challenge – announced 6/5/08 Water Initiative – recent ASHRAE presentation DOE SEER update

• Current Technologies of Interest Building-Integrated Cooling Swimming-Pool Heating WicKool Dedicated Outdoor Air Systems

WCEC Technology Portfolio• Most technologies appropriate for new and retrofit

Rooftop units

Evaporative cooling technologies

• Hybrid evaporative/vapor-compression equipment

• Water-cooled condensers

Swimming-pool-based air conditioners

Thermal distribution performance

Night-sky radiative cooling

• Some opportunities unique to new construction:

Low-cost chilled water storage

Radiant floor cooling

Example Technology: DualCool

• Accessory system for RTUs

• Pre-cools condenser and ventilation air

• DOES NOT add moisture to indoors

• 25-30% energy and demand savings

A

B

C

D

SYSTEM SCHEMATIC

A - High quality condenser air pre-cooler

B - Pump & copper supply/return piping

C - Ventilation air precooling coil

D - Controls

Example Technology: Roll-Out Radiant Floor

• Prior cost $6-7/ft2

• Rollout cost ~$2/ft2

• Full-scale installation at Wal-Mart store

Example Technology: Radiant Floor Benefits

• Reduces latent cooling and blower energy

• Facilitates non-compressor cooling

• Projected savings 60-65%

• Projected demand reduction 45%+

Example Thermal Storage Technology• Residential/Commercial Swimming Pools

Night-time cooling (non-refrigerative) makes pool water available for day-time low-temperature heat rejection

• 20-40oF reduction in refrigerant condensing temperature

• 20-50% improvement in EER – higher at peak conditions

Rejected heat serves useful function • Eliminates/reduces gas consumption for pool heating

WCEC Market Activities• Demonstrations

Integrated retrofits for strip malls Technology demonstrations on state-owned buildings

• Policy and Market Drivers Western Cooling Challenge Hot, Dry Air Conditioners Water Initiative

• Water management for evaporative air conditioning

DOE • SEER regional standards

• Lab tests for annual savings predictions

Western Cooling Challenge

• Target Market: Rooftop Units (RTUs) with 3 – 30 ton capacity (>500-unit production capacity)

RTUs cool 70% of non-residential floor space in the Western US

• Target Performance: 40% reduction in energy use and peak electricity demand

• Reward Structure: MOUs w CA IOUs and SMUD for incentive programs – Retailer program sponsorship

Western Cooling Challenge: Schedule  

January 2009 Laboratory testing of WCC entries can begin

June 2009 Field testing of WCC entries can begin

January 2010 Shipments of WCC-compliant products can begin 

New Indirect Heat Exchangers

Coolerado

• Unique multi-stage indirect design

• 90%+ effectiveness, balanced flow

• 250 cfm per module, 10” high, 20” long, 19” wide

• Used in Coolerado & Desert Cool Aire prototypes

New Indirect Heat Exchangers

HyPak

• High-speed production process

• 80%+ effective in lab test

• Delivered 4.3 tons for 2’ width

• Many other applications

Example Market Issue: Water Initiative• Impediments to water-based cooling

On-site water use

Equipment maintenance

• Successful water-based systems for buildings Cooling towers Pressurized domestic water Pools Irrigation

• Water conservation Techniques exist

Not optimized for small-scale evaporative cooling

Evaporative Cooling: Water Use Metrics

• Evaporative Cooling Water Use

Cooling potential = mass of water * heat of vaporization

Potentially as low as 1.37 gallons/ton-hr

• Maintenance Water Use

Rule of Thumb: 2/3 evaporation, 1/3 maintenance

Large Impact of Water Quality

• Indirect Water Consumption for Electricity Generation

Enormous range of values - 0.1-72 gal/KWh€

Water Use for Condenser-Air Pre-Cooling• Analysis Technique

Calculate change in EER with respect to condenser air temperature

• Relatively linear

• 1-2% change per oF Calculate condenser

temperature change per unit of water evaporated

Use EER change to calculate extra cooling delivered for the same electricity consumed

€

Example Market Issue: Water Issue Resolution

• Roles for the WCEC

provide “institutional memory” on water issues

• water-use yardsticks

access large cadre of water scientists at UCD

pursue water conservation solutions

• save rain runoff for cooling

• irrigate w/flushed water

• night-sky water cooling

Wine Industry Opportunities

• Evaporative condensing and pre-cooling

• Pre-cooled ventilation air (e.g. Fetzer)

• Thermal storage (wine is ideal!)

• Radiant cooling to reduce blower power (may need desiccants in high humidity areas)

• CHP (e.g. Vineyard 29)

• Others?

WCEC Mission Summary

“Partner with stakeholders to identify technologies, conduct research and demonstrations, disseminate information, and implement programs that reduce

cooling-system electrical demand and energy consumption in the Western United States.”

http://wcec.ucdavis.edu/

Mark Modera

mpmodera@ucdavis.edu