Solar Water Heating Therm – inology!

USH2O Annual Meeting 2011

Tim Merrigan

National Renewable Energy Laboratory

October 17, 2011

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 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 (ISO) – International Association of Plumbing & Mechanical Officials (IAPMO) – Solar Rating & Certification Corporation (SRCC) – North American Board of Certified Energy Practitioners (NABCEP)

Solar Water Heating Systems Basic System Types

Passive Active Solar Water Heating Systems Basic System Types

• Passive – • Direct (uses potable water) • Indirect (uses a ) – Integral Collector Storage • Direct • Indirect

• Active (forced circulation) – Direct – Indirect • Pressurized glycol • Drainback (uses distilled water)

Solar Water Heating Systems System Types

Indirect

Direct

Colorado Hawaii 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 Indirect Drainback Forced Circulation Direct Forced Circulation

Indirect Pressurized Glycol 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) Solar Water Heating Systems Open Indirect Drainback System

Indirect Drainback Forced Circulation (with unpressurized solar storage tank) Open Direct Drainback System Solar Pool Solar Air Heating Systems Open Circulation System

Solar Air Space Heating 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 Solar Water and Space Heating Systems Open System Examples Indirect Drainback Forced Circulation Transpired Collector

Direct Drainback Solar Pool Heating System Air-based PV/Thermal System Solar Thermal Standards, Codes, and Certification Listings Solar Thermal Standards Solar Thermal Certification Organizations

• Solar Thermal Standards (Consensus) – American Society of Heating, Refrigerating, and Air-conditioning (ASHRAE) – American Society for Testing and Materials (ASTM International) – Australian Standards and New Zealand Standards (AS/NZS) – European Committee for Standardization (CEN) – International (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 Consensus Standards (selected)

• 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 Certification Proprietary Listing

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 Installer 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

SWH Therm – inology! Summary

• 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! Words do matter!

Thank You!