NREL is a national laboratory of the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy operated by the Alliance for Sustainable Energy, LLC

USH2O Annual Meeting 2011

Tim Merrigan

National Renewable Energy Laboratory

October 17, 2011

Solar Water Heating Therm – inology!

SWH Therm – inology! Outline

• Solar Water Heating Systems

– Ways to describe SWH systems

• Active and passive

• Direct and indirect

• Open and closed

• “Open loop” and “closed loop” – NOT!

• SWH Standards, Codes, Guidelines, and Certificants – International Organization for Standardization (ISO)

– International Association of Plumbing & Mechanical Officials (IAPMO)

– Solar Rating & Certification Corporation (SRCC)

– North American Board of Certified Energy Practitioners (NABCEP)

Active

Passive

Solar Water Heating Systems Basic System Types

• Passive

– Thermosiphon

• Direct (uses potable water)

• Indirect (uses a heat exchanger)

– Integral Collector Storage

• Direct

• Indirect

• Active (forced circulation) – Direct

– Indirect • Pressurized glycol

• Drainback (uses distilled water)

Solar Water Heating Systems Basic System Types

Direct

Indirect

Solar Water Heating Systems System Types

Colorado Hawaii

Indirect Drainback

Forced Circulation

Indirect Pressurized Glycol

Forced Circulation

Solar Water Heating Systems Common Mainland U.S. Active System Types

Indirect Drainback Forced Circulation

Indirect Pressurized Glycol Forced Circulation

Solar Water Heating Systems Closed System Examples

Direct Forced Circulation

Direct Integral Collector Storage

Solar Water Heating Systems Closed Indirect Drainback System

Indirect Drainback

Forced Circulation

(with an external heat

exchanger and a

pressurized solar

storage tank)

Indirect Drainback

Forced Circulation

(with unpressurized solar

storage tank)

Solar Water Heating Systems Open Indirect Drainback System

Open Direct Drainback System Solar Pool Heating System

Solar Air Space Heating

Solar Air Heating Systems Open Circulation System

Open Solar Heating Systems Transpired Collectors

NREL Research Support Facility

Golden, CO

NREL Waste Handling Facility

Open Solar Heating Systems Air-based PV/Thermal System

Indirect Drainback Forced Circulation

Direct Drainback Solar Pool Heating System

Solar Water and Space Heating Systems Open System Examples

Transpired Collector

Air-based PV/Thermal System

Solar Thermal Standards,

Codes, and Certification

Listings

• Solar Thermal Standards (Consensus)

– American Society of Heating, Refrigerating, and Air-conditioning

Engineers (ASHRAE)

– American Society for Testing and Materials (ASTM International)

– Australian Standards and New Zealand Standards (AS/NZS)

– European Committee for Standardization (CEN)

– International Standards Organization (ISO)

• Solar Thermal Certification Organizations (Proprietary Listing)

– International Association of Plumbing & Mechanical Officials

(IAPMO)

– North American Board of Certified Energy Professionals (NABCEP)

– Solar Rating & Certification Corporation (SRCC)

Solar Thermal Standards Solar Thermal Certification Organizations

• ASHRAE 93-2010, Methods of testing to determine the thermal

performance of solar collectors

• ASHRAE 96-2008, Methods of testing to determine the thermal

performance of unglazed solar collectors

• EN 12975-2:2006, Thermal solar systems and components -

Solar collectors - Part 2: Test methods

• ISO 9806-1:1994, Test methods for solar collectors – Part 1:

Thermal performance of glazed liquid heating collectors

including pressure drop

• SRCC 100-2010, Test methods and minimum standards for

certifying solar collectors

• SRCC 150-2010, Test methods and minimum standards for

certifying innovative solar collectors

Solar Thermal Standards Consensus Standards (selected)

Solar Rating & Certification Corporation (SRCC)

– Certification of solar collectors (SRCC Operating Guideline 100)

– Over 800 solar collector models have been approved for SRCC OG-100 certification listing

• Glazed flat-plate and evacuated tube collectors

• Unglazed polymer collectors

• Concentrating collectors

– Certification of complete solar systems (SRCC Operating Guideline 300)

– Over 1900 solar water heating system models have been approved for SRCC OG-300 certification listing

• Forced circulation systems

• Thermosiphon systems

• Integral collector-storage systems

Solar Thermal Certification Proprietary Listing

International Association of Plumbing & Mechanical

Officials Research & Testing (IAPMO R&T)

– Products listed in compliance with the Uniform Codes:

• Uniform Solar Energy Code (USEC),

• Uniform Plumbing Code (UPC),

• Uniform Mechanical Code (UMC),

– 10 solar collector manufacturers have received USEC listings

– 2 manufacturers of storage tanks with heat exchangers have

USEC and UPC listings

– 8 solar water heating systems have received various listings:

USEC, UPC, Energy Star, and Classified

– Products can also be listed in compliance with an IAPMO

Product Standard

Solar Thermal Certification Proprietary Listing

North American Board of Certified Energy Professionals

(NABCEP)

– Solar Heating Installer Certification

– Solar Heating Entry Level Certification

– Solar PV Installer, Solar PV Entry Level, PV Technical Sales

Professional Certification

– Small Wind Installer Certification

– Installer qualification standards

• Knowledge, skills, safety

– Written examination

• NABCEP installer certification required in some

incentive programs

Solar Thermal Installer Certification Proprietary Listing

• Be wary when you hear the term “open loop” – often

it is used to describe direct systems that are actually

closed!

• The term “open” in all plumbing and hydronic

systems means “open to the atmosphere.”

• The term “closed loop” is typically used correctly;

however, almost all direct and indirect SWH systems

are closed, i.e., not open to the atmosphere.

• Consensus “standards” are different from both

proprietary “codes” and “operating guidelines”

• Certification organizations have proprietary listings

that are useful to manufacturers, building officials,

utilities, and consumers.

SWH Therm – inology! Summary

Thank You!

SWH Therm – inology! Words do matter!