Overview of Some Projects in NIST’s Building Energy Research Program

1. Overview of Some Projects in NIST’s Building Energy Research Program Mark A Kedzierski National Institute of Standards and Technology Gaithersburg, Maryland

2. Building Energy Use is Large and Growing 40% of U.S. Primary Energy Consumption The combined residential and commercial buildings sectors is the largest consumer of energy in the U.S. 72% of U.S. Electricity Source: 2007 Buildings Energy Data Book. Tables 1.1.3, 1.2.3, 1.3.3 Buildings Is The Fastest Growing Sector 55% of U.S. Natural Gas

3. NIST’s Mission To promote U.S. innovation and industrial competitiveness by advancing • measurement science, • standards, and • technology In ways that enhance economic securityandimprove our quality of life Article I, Section 8: The Congress shall have the power to…fix the standard of weights and measures Becausebuildings are a controlling portion of our nation’s energy use, building energy research can significantly enhance economic security and improve the quality of life

4. Current Building Energy Measurement Science Research • Photovoltaic Measurements and Models • Refrigerant Heat Transfer Enhancement • HVAC Simulation Tools/Fault Detection • Thermal Insulation Measurements • Fuel Cell Performance/CHP Performance Ratings • Sensors for Improved Building Monitoring • Energy Efficient Ventilation Strategies • Energy Efficiency of Appliances • Net-Zero House

5. Photovoltaic Measurements and Models Objective: Improve current test methods and simulations in order to facilitate the use of PV in buildings Improvement/Validation of Simulation Models Technology Comparisons

6. Photovoltaic Measurements and Models (cont.) Long pulse solar simulator Improved Measurement Techniques Solar Tracker Advanced Building Energy Technologies

7. Nanofluids Heat Transfer Measurements Technical challenge: Nanolubricants offer the opportunity for cost-neutral performance improvement. The lack of refrigerant/nanolubricant boiling heat transfer measurements makes it very difficult to understand the fundamental mechanisms that govern the nanoparticle/bubble interaction. Research tools and methods: Pool boiling test apparatus – pool boiling heat transfer Stabinger viscometer – nanolubricant viscosity Dynamic light scattering apparatus – nanoparticle size Findings: Al2O3 nanolubricants can significantly enhance refrigerant pool boiling (on average, between 50 % and 150 %). The enhancement depends on the nanoparticle material, size, volume fraction, dispersion quality. Good dispersion quality is essential.

8. Simulation Tools for HVAC Equipment NIST develops software tools that facilitate designing optimized equipment. Goals: Increased energy efficiency Lower cost products Faster time to market REFLEAK predicts a composition shift of zeotropic refrigerant mixtures due to sequential leaking and recharging. Composition shifting typically results in degradation of efficiency. CYCLE_D evaluates refrigerant COP in the basic and advanced vapor-compression cycles. Simulation of an entire air-conditioning system to estimate the effect of design changes upon efficiency. Particle Image Velocimetry (PIV) is used to characterize the air flow distribution through finned tube heat exchangers.

9. Automated Fault Detection and Diagnostics for Residential Heat Pumps NIST is developing Fault Detection and Diagnostic methodologies for residential heat pump systems that will ensure a quality installation and sustained efficiency throughout the equipment’s life span. Goals: Quality initial installations Greater thermal comfort Reduced refrigerant emissions Increased energy efficiency Reduced life-cycle operating costs System analysis and fault classifier Residential split-system heat pump

10. HVAC Fault Detection and Diagnostics NIST has pioneered the development of embedded measurement and analysis techniques to detect faults in HVAC equipment and controls • APAR – Air Handler Performance Assessment Rules • VPACC – VAV box Performance Assessment Control Charts • Unique laboratory facilities to emulate building systems • Collaboration with control system manufacturers to test results in commercial products NIST Virtual Cybernetic Building Testbed Facility – Used to conduct research in automated fault detection and other aspects of integrated building control systems

11. Thermal Insulation Measurements • Since 1912, NIST has provided thermal resistance measurements to the thermal insulation industry. • 1016-mm Guarded Hot Plate (GHP) Apparatus • 500 mm GHP designed to test from 90 K to 900 K • Vacuum Insulation Panels tested in calorimeter • NIST Standard Reference Database 81 (http://srdata.nist.gov/insulation/)

12. 500 mm currently under evaluation Developed for industrial thermal insulation user community Design range: 90 K to 900 K 10-4 torr to 800 torr Collaboration with ASTM C16.30 Reference Materials Task Group underway to develop next the generation of high-temperature thermal insulation reference materials Thermal Insulation Measurements (cont.) NIST's High-Temperature Guarded-Hot-Plate Apparatus

13. Sensors for Improved Building Monitoring NIST is exploring novel sensor technology that could be used as part of monitoring systems to determine energy consumption in buildings: • Non-invasive techniques to evaluate integrity of thermal envelopes • Wireless sensors • Energy monitoring systems

14. Energy Efficient Ventilation Strategies NIST has been developing simulation methods, design guidance and tools, technology assessments of strategies, and standards to provide adequate ventilation in an energy efficient manner. Carbon dioxide based demand controlled ventilation Dedicated outdoor air systems Displacement ventilation Natural and hybrid ventilation

15. Fuel Cell/Cogeneration Performance Ratings • NIST is developing rating methodologies to help consumers gauge the performance of fuel cell systems and other combined heat and power (CHP) technologies for building applications. • Residential Fuel Cell Units • Internal Combustion CHP • Stirling Engine CHP

16. Residential Appliance Program Develops standardized test procedures for common household appliances such as dishwashers, water heaters, refrigerators, mini-split AC, and pool heaters Assists in finding data for the Federal Trade Commission’s Energy Guide appliance rating labels Provides EPA and DOE with information for the Energy Star classification

17. Net-Zero House Unique Features • Advanced framing • Fenestration units readily replaced • High-performance building envelope • Reconfigurable photovoltaic array (1.6 to 9.7 kW) • Variable collector size and storage tank capacity solar hot water system • Smart Grid Ready • Use of low emitting materials for improved indoor air quality • Multiple zoning capabilities (floor, register, perimeter versus central) • Small duct, high velocity air distribution system • Dedicated ductwork for humidification/dehumidiification heat recovery systems • Air-to-air central heat pump system • Multi-split heat pump system • Earth Coupled Heat Pump system with three distinct earth coupled fields Objective: Demonstrate Net-Zero Energy for a typical home and generate “real world” field data to validate/improve models To be built on the NIST campus

18. Project Contacts • Photovoltaic Measurements and Models: brian.dougherty@nist.gov • Refrigerant Heat Transfer Enhancement: mark.kedzierski@nist.gov • HVAC Simulation Tools/Fault Detection: vance.payne@nist.gov • Thermal Insulation Measurements: robert.zarr@nist.gov • Fuel Cell Performance/CHP Perf. Ratings: mark.davis@nist.gov • Sensors for Improved Building Monitoring: william.healy@nist.gov • Energy Efficient Ventilation Strategies: andrew.persily@nist.gov • Energy Efficiency of Appliances: francisco.castro-roman@nist.gov • Net-Zero House: hunter.fanney@nist.gov