NREL Report Template - Energy



Measurement and Verification Project Plan:Gaseous Air Cleaning TechnologiesNational Renewable Energy LaboratoryGolden COJune 30, 2015Internal Report Prepared for Building Technologies OfficeOffice of Energy Efficiency and Renewable EnergyU.S. Department of EnergyNomenclature or List of AcronymsASHRAEAmerican Society of Heating, Refrigerating and Air-Conditioning EngineersCO2carbon dioxideDOEU.S. Department of EnergyHVACheating, ventilation, and air conditioningIAQindoor air qualityIAQPIndoor Air Quality ProcedureIEQindoor environmental qualityM&Vmeasurement and verificationO&Moperations and maintenanceppbparts per billionppmparts per millionRHrelative humidityTtemperatureTVOCtotal volatile organic compoundsVOCvolatile organic compoundsVRPVentilation Rate ProcedureTable of Contents TOC \h \z \t "NREL_Head_02,2,NREL_Head_01,1,NREL_Head_03,3,NREL_Head_01_Numbered,1,NREL_Head_02_Numbered,2,NREL_Head_03_Numbered,3" 1Introduction PAGEREF _Toc423450302 \h 12Technology Description PAGEREF _Toc423450303 \h 23Demonstration Objectives PAGEREF _Toc423450304 \h 34Site Selection PAGEREF _Toc423450305 \h 55Demonstration Design PAGEREF _Toc423450306 \h 85.1Monitoring Period PAGEREF _Toc423450307 \h 85.2Baseline Energy Performance Determination PAGEREF _Toc423450308 \h 85.3Baseline IAQ Determination PAGEREF _Toc423450309 \h 85.4Instrumentation and Monitoring PAGEREF _Toc423450310 \h 96Performance Analysis and Assessment PAGEREF _Toc423450311 \h 11References PAGEREF _Toc423450312 \h 13List of Figures TOC \h \z \t "NREL_Figure_Caption" \c Figure 1. Typical installation of the air cleaning technology in the return air stream PAGEREF _Toc423450313 \h 2List of Tables TOC \h \z \t "NREL_Table_Caption" \c Table 1. Technology Performance Objectives, Metrics, and Data Requirements PAGEREF _Toc423450397 \h 4Table 2. Site Information PAGEREF _Toc423450398 \h 5Table 3. High-Level Criteria PAGEREF _Toc423450399 \h 6Table 4. Systems-Related Criteria PAGEREF _Toc423450400 \h 7Table 5. Utilities-Related Criteria PAGEREF _Toc423450401 \h 7Table 6. Continuous Performance Monitoring and Instrumentation PAGEREF _Toc423450402 \h 9Table 7. Short-Term Performance Monitoring and Instrumentation PAGEREF _Toc423450403 \h 10IntroductionThis report provides a measurement and verification (M&V) plan for gaseous air cleaning technology used to clean a building’s return airstream. The intent is to scrub carbon dioxide (CO2) and other gaseous contaminants from the return air in order to reduce the outside air and the associated energy required to condition the outside air. This plan provides information about: The technology and how it is expected to reduce energy consumptionThe demonstration objectives, technology performance objectives, technology performance metrics, and data requirementsThe demonstration design, including the instrumentation required to enable data collection and performance evaluationThe analysis methods that will be used to estimate the performance.The demonstration plan presents assumptions about the technology to be tested, demonstration objectives, and proposed M&V approaches. The demonstration plan should be customized for each technology and demonstration site.This demonstration plan assumes that the outside air (OA) ventilation rate for acceptable indoor air quality (IAQ) is defined by ASHRAE Standard 62.1-2013, Ventilation for Acceptable Indoor Air Quality (ASHRAE 2013a). Standard 62.1 presents three methods to achieve compliance with the standard: the ventilation rate procedure (VRP), indoor air quality procedure (IAQP), and natural ventilation procedure. This demonstration plan assumes that the OA ventilation in the building before air cleaning system is set by the prescriptive VRP and that the IAQP is used is determine the reduction in OA ventilation rate with the air cleaning system. The natural ventilation procedure is not used in this demonstration plan. In addition, the Standard 62.1 requirements for exhaust ventilation must be met for all three methods.Technology Description The focus of this demonstration M&V project plan are air cleaning technologies that selectively removes gaseous contaminants from the return airstream with the goal of reducing the required OA ventilation requirements. It is assumed that the technology used for this demonstration plan uses a regenerable sorbent material to adsorb carbon dioxide (CO2) and volatile organic compounds (VOCs) from the air. The sorbent material absorbs the gaseous chemicals during sorption cycle and must have a regeneration cycle to eliminate the absorbed gases usually by heating the sorbent material and exhausting the gases. The energy consumed during the regeneration cycle must be lower than the energy saved by reducing the OA ventilation to save energy. A typical installation in the return airstream near the air handling unit (AHU) is shown in REF _Ref398454950 \h \* MERGEFORMAT Figure 1. During the air cleaning cycle, a portion of the return air is processed through the air cleaner and the OA damper is closed slightly to reduce the OA brought into the building. Reducing the amount of OA ventilation required can reduce HVAC loads and provide significant energy savings and peak demand reduction. In addition, there is a potential to improve the cooling systems ability to meet the latent cooling requirements in hot-humid climates because the outside air is the major source of humidity in a building. During the regeneration cycle, the dampers to the return airstream are closed and the regeneration airstream dampers are opened to purge the captured gases from the sorbent material.Figure SEQ Figure \* ARABIC 1. Typical installation of the air cleaning technology in the return air streamDemonstration ObjectivesThe proposed objectives for this demonstration are divided into two technical and four deployment related objectives. The technical performance objectives are to:Determine the energy performance and energy cost savings of operation with the air cleaning technology compared to baseline operation without the air cleaning technology. Confirm that indoor environmental quality (IEQ) meets the requirements for air quality and thermal comfort defined in ASHRAE Standards 62.1 and 55 (ASHRAE 2013a, 2013b).The deployment-related objectives are to: Identify and document the technical and practical challenges that emerge in design, installation, control, and operation of the air cleaning system.Document the level of occupant and maintenance staff satisfaction with the air cleaning system.Estimate the economic performance of the air cleaning system.Estimate the potential market impact and document potential challenges for wide-scale deployment.Building on these objectives, REF _Ref398534181 \h Table 1 shows the general performance objectives, metrics, and data requirements for this technology demonstration. These requirements should be modified for each demonstration technology and site to accommodate demonstration specific details. Additional objectives may be added for each technology and site, depending on the needs of the building and the occupants. The specific indoor air contaminants of concern and performance targets should be determined in coordination with the subject matter experts for each project and the building owners to identify and measure occupant and maintenance staff satisfaction for each site. Close work with building owners will also be critical to make sure equipment receives proper attention and that operational issues impacting testing results are quickly resolved. Information from owners on O&M costs, work orders, and occupancy changes are important for evaluation. Owner support is also needed to conduct air quality monitoring particularly when the monitoring will be performed in occupied spaces during occupied hours. Table SEQ Table \* ARABIC 1. Technology Performance Objectives, Metrics, and Data Requirements Technology Performance ObjectivePerformance Metric(s)Preliminary Performance TargetData RequirementsMaintain target CO2 levels Indoor CO2 concentration in ppmTBD (site specific)Continuous measurements outdoor CO2 concentration and indoor CO2 concentrations in selected spaces and in the return air ductsMaintain acceptable levels of specific contaminants of concern and contaminant mixtures of concernTBD (site specific)TBD (site specific)Continuous measurements of TVOCs and short-term measurements of specific contaminants Maintain comfortable indoor temperature and relative humidity (T&RH)T&RHWithin Standard 55 comfort requirementsT&RH from selected spacesReduce outside air requirementsOutside airflow rateTBD (site specific)Outside airflow rates. Measure building pressurization to maintain positive.Reduce energy consumption for treating outside airChiller, DX, or boiler energy consumptionTBD (site specific)Chiller, DX and boiler energy as required for each project Reduce overall HVAC energy consumption15-minute and daily HVAC energy consumptionTBD (site specific)15-minute energy data for chillers, air handling unit fans, air cleaning technology fans and regeneration. 15-minute or daily data for boiler or furnace gas consumption. 15-minute ambient T&RH (for normalization of energy data)Maintain occupant satisfaction Occupant satisfaction with IAQ> 80% satisfiedOccupant satisfaction survey during air cleaning system operation Net annual decrease in HVAC related O&M costsHVAC O&M costsNo increase in O&M costsHVAC O&M costs, chiller run time, energy costsDetermine the effective life of the sorbent material cartridgesAverage replacement age1 yearContaminant removal rates measured every 3 monthsSite SelectionThe general strategy for selecting sites is based on the potential for energy savings. This technology has the potential for the greatest savings in extreme climates where large amounts of energy are required for heating or cooling and dehumidifying the outside air. Buildings with high ventilation loads such as schools, office buildings, assembly buildings, and retail buildings are good candidates. Ideal site candidates would have active building automation systems and sub metering which can be accessed remotely. Healthcare facilities also have high ventilation loads, but they are very sensitive to IEQ and are recommended for future demonstrations. Required site information and site selection criteria were developed to assist in selecting demonstration sites and are listed in REF _Ref420750275 \h Table 2 through REF _Ref420750290 \h Table 5. Table 2. Site InformationBuilding NameBuilding Primary ActivityLocation (city, state)Building area (ft2)Weekly operation hoursHVAC system typeTable 3. High-Level CriteriaOwner is ready to move, interested in making the demonstration a successBuilding staff will be accessible to the demonstration teamAccess to return air ducts and space to install the air cleaning systemOutside air dampers are operable and can be controlled by the air cleaning systemTotal air flow rate > 10,000 cfmOutside air flow rates > 20% of total air flow ratesGreater than 50 hours per week with ventilation operationMinimal or no use of manually operable windowsOther ventilation load reduction strategies implemented (DCV, ERV, etc.)Building automation system allows link to the air cleaning system control platform or control of the OA dampers directlyTable 4. Systems-Related CriteriaChilled water metering availableWhole building electrical meterElectrical submeteringUp-to-date mechanical drawings availableNo large HVAC maintenance or replacement plans in the next yearAll mechanical systems operationalSpace/AHU relationship knownAvailable TAB report (vintage)Available OA/Exhaust measurementsBuilding ventilation challenges (known IAQ issues, etc.)Available occupancy and/or people countAvailable trend logs from BASTable 5. Utilities-Related CriteriaSite has high utility rateSite has demand charges or other incentives for peak load reductionSite potentially has access to rebates for installationDemonstration DesignMonitoring PeriodThis technology has the potential to impact HVAC operation year round, but primarily in the heating and cooling seasons when the conditioning of the extreme outdoor air temperatures and humidity levels are the most energy intensive. Continuous monitoring systems should ideally continue for 1 year, but at least 9 months for locations with significant heating and cooling loads and at least 6 months for locations with very few or no heating requirements. Short-term monitoring of IAQ and airflow rates should be conducted during each season to determine the impacts on elimination of specified contaminants of concern and to verify airflow rates. It may be of interest to follow up with each site after 1 year of operation to verify proper performance and interview the maintenance staff about relevant maintenance practices and unusual system behavior.Baseline Energy Performance DeterminationThe ventilation baseline for most sites should be the as designed operation of the building. However, each site should be evaluated to ensure that the as designed OA ventilation rate satisfies the Standard 62.1 prescriptive VRP requirements. The OA ventilation rates may need to be adjusted if they are lower than the Standard 62.1 VRP rates. Proper operation of the OA dampers will be verified for each air system. Performance analysis of the air cleaning system will best be determined by operating the system in alternating on and off periods during each season with the full monitoring system in place and short-term air quality measurements. The timing and frequency of the on-off periods will be determined for each site with technology vendor and the building operations staff. The off period will have to be long enough (perhaps a week or longer) to allow the building and building systems to fully achieve a new dynamic equilibrium with the ambient and operational conditions. Baseline O&M practices and costs will be gathered from interviews with the maintenance staff and review of maintenance records.Baseline IAQ DeterminationThe IAQP in Standard 62.1 is a performance approach in IAQ and allows the OA ventilation rate to be reduced below the VRP provided that the IAQ is maintained within acceptable limits. Following the IAQP may actually lead to higher OA ventilation rates if it is determined that the IAQ is not within the acceptable levels with the VRP. Standard 62.1 does not define acceptable IAQ, but Appendix B is provided as an informative appendix that provides a summary of contaminant exposure limits and guidelines issued by several recognized authorities. The first step of the baseline IAQ measurements is to determine the contaminants of concern (COC) in the building and measure their concentrations and the allowable COC concentration limits. Determining appropriate exposure maximum concentration limits involves working with the building owner to understand the potential contamination sources. Factors that go into the selection of appropriate maximum concentration limits include the types of occupants, how long are occupants in the space exposed to the contaminant (hrs/day, days/year, or continuous), and the potential sensitivity to contaminants (Williams and Deru 2015).Instrumentation and MonitoringThe instrumentation and monitoring plan is developed to determine the performance metrics in REF _Ref398534181 \h Table 1. The data requirements from REF _Ref398534181 \h Table 1 necessitate a combination of continuous measurements and short-term periodic measurements. A list of monitoring points and instrumentation for continuous measurements is presented in REF _Ref399387579 \h Table 6, and the short-term measurements in REF _Ref399389424 \h Table 7 will be taken once or periodically during both the baseline operation and the air cleaning system operation. The instrumentation and monitoring plans will support direct measurement of performance along with development and calibration of whole-building energy models. Table SEQ Table \* ARABIC 6. Continuous Performance Monitoring and InstrumentationMonitoring PointType of MeasurementUnitsInstrumentationChiller or DX energyElectrical or chilled waterkWh or BtuWatt-hour meters with current transformers, water flow meters and CHW supply and return temperaturesAir handling unit fan energyElectricalkWh Watt-hour meters with current transformersBuilding heating energyElectrical, hot water, or gaskWh or BtuTBDWhole building energyElectrical, gas, and other fuelskWh or BtuTBDFan energyElectricalkWhWatt-hour meters with current transformersRegeneration energyElectricalkWhWatt-hour meters with current transformersSpace and return air CO2CO2 concentrationppmCO2 sensorsOutdoor air CO2CO2 concentrationppmCO2 sensorSpace TVOCTVOC concentrationppbTVOC sensorsSpace temperatureTemperature°CT&RH sensorsSpace RHRH%RHT&RH sensorsAmbient temperatureTemperature°CT&RH sensorAmbient RHRH%RHT&RH sensorGlobal horizontal solar radiationIrradianceW/m2PyranometerWind speedWind speedm/s2AnemometerTable SEQ Table \* ARABIC 7. Short-Term Performance Monitoring and InstrumentationMonitoring PointType of MeasurementUnitsInstrumentationOutside airflow ratesAirflow ratem3/sTBD based on each siteSpecific VOC species determined as potential COCs ConcentrationTBDTBD based on contaminantFormaldehyde concentrationConcentrationPPBTBDIndoor air qualityOccupant satisfaction of acceptable IAQ%Survey or untrained panelOperation and maintenance (O&M) costsInterviews and work orders$, number and types of work ordersInterview O&M staffA site-specific instrumentation and monitoring plan will be developed for each installation accounting for the technology installation, existing systems, and existing instrumentation. The final demonstration M&V plan should be reviewed with DOE, the technology vendor, and the building staff.Performance Analysis and AssessmentIn the final assessment, report on the following performance areas for each demonstration site with detailed monitoring:IAQ performance, including CO2 and the COCs determined for each siteThermal comfort conditions to ensure normal conditions are maintained and to include changes in the thermal conditions in the energy analysis if necessaryVentilation rate changesDaily, monthly, and annual energy and energy cost performanceO&M costs and requirements including training requirements and durability of equipment. Occupant satisfaction survey results and any concerns, where applicable.Report on these performance areas with the objectives in REF _Ref398534181 \h Table 1 via the following approaches:Determine if the IAQ/IEQ performance with the air cleaning system operation meets the requirements of Standards 62.1 55. Compare peak and average contaminant concentrations with IAQ exposure limits established by the California Office of Environmental Health Hazard Assessment (OEHHA 2012), the World Health Organization (WHO 2010) or the National Institute for Occupational Safety and Health (NIOSH 2010).When comparing energy consumption with and without the air cleaning technology, normalize results to control for weather differences between the baseline and technology test periods. Develop regression models to normalize energy consumption based on: (1) outdoor air temperatures or degree days; and (2) humidity. Other normalization factors will be considered if a strong correlation with energy performance is suspected and if the data necessary for normalization are readily available.Determine the operational economic performance from annual estimated energy costs, maintenance costs, and projected cartridge replacement costs for each demonstration site. Complete a simple payback and return on investment calculation based on estimated air cleaning technology costs for a non-demonstration installation and the estimated operational costs.Determine O&M requirements by interviewing the maintenance staff and reviewing maintenance records. Determine occupant satisfaction with occupant satisfaction surveys where applicable.The results from the demonstration may be used to investigate applications and potential impacts beyond these demonstration buildings. Whole-building energy modeling using EnergyPlus (DOE 2014) with the DOE reference building models (Deru et al. 2011) will be applied to estimate the energy savings potential for a broader range of building types, operating schedules, and locations. The process of adding the air cleaning technology to the reference building models will consist of applying a modified outside air schedule, adjusted infiltration schedule when the air cleaning technology is on, a fan and pressure drop in the return airstream to represent the air cleaning technology, and a schedule for the regeneration fan and heat load. No other changes to the reference building models will be required. The whole-building energy models can also be used to compare performance of this technology to alternative approaches to reducing ventilation air requirements such as dedicated outdoor air systems, demand controlled ventilation, and economizer operation.References ASHRAE (2013a). Ventilation for Acceptable Indoor Air Quality. ANSI/ASHRAE Standard 62.1. Atlanta, GA: American Society of Heating, Refrigerating and Air-Conditioning Engineers.ASHRAE (2013b). Thermal Environmental Conditions for Human Occupancy. ANSI/ASHRAE Standard 55. Atlanta, GA: American Society of Heating, Refrigerating and Air-Conditioning Engineers.Deru, M.; Field, K.; Studer, D.; Benne, K.; Griffith, B.; Torcellini, P.; Liu, B.; Halverson, M.; Winiarski, D.;Rosenberg, M.; Yazdanian, M.; Huang, J.; Crawley, D. (2011). U.S. Department of Energy Commercial Reference Building Models of the National Building Stock. NREL/TP-5500-46861.Golden CO: National Renewable Energy Laboratory. DOE (2014). EnergyPlus Energy Simulation Software. Washington, D.C.: U.S. Department of Energy.NIOSH (2010). NIOSH Pocket Guide to Chemical Hazards: Formaldehyde from (2012). Air Toxicology and Epidemiology from , S. and Deru, M. (2015). Retailer Ventilation Best Practice Guide. NREL Technical Report to be published.Golden CO: National Renewable Energy Laboratory.WHO (2010). WHO guidelines for indoor air quality: selected pollutants. Denmark: World Health Organization Europe. ................
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