Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “VENTILATION”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Regional difference and related cooling electricity savings of air pollutant affected natural ventilation in commercial buildings across the US

Maintaining indoor air pollutants under acceptable levels is significant to protect occupants from exposure to excessive air pollutants in natural ventilation. In this paper, using the representative air pollutant concentration data, we present the natural ventilation usability with associated cooling energy saving potentials in different location settings (urban and city center, suburban and rural) of the US under the influence of local weather conditions and major outdoor air pollutants, i.e. PM2.5, PM10 and ozone. It is found that the impacts of air pollutants on natural ventilation are usually higher in urban/suburban areas than rural areas (up to 25% difference) with the PM2.5 being the most significant outdoor air pollutant affecting natural ventilation usage. Furthermore, ozone could become increasingly influential on natural ventilation as moving from urban to suburban/rural areas. As to the cooling energy saving considering the impacts of outdoor air pollutants, natural ventilation is estimated to save approximately 10%–40% cooling energy (800–2600 kWh per small commercial building) annually in different location settings of investigated areas across the US. The following economic analysis demonstrates that these electricity savings lead to approximately 80–540 dollars annual savings of building operation cost per building. If the time of use rate is adopted, these cost savings could further increase by approximately 20% (Los Angeles) to more than 50% (Albuquerque) depending on different rate structures, which further demonstrates the potential of adopting natural ventilation as a sustainability measurement with benefits for building owners without compromising occupants health.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2016

WE-AB-202-07: Ventilation CT: Voxel-Level Comparison with Hyperpolarized Helium-3 & Xenon-129 MRI

Purpose: To compare the spatial correlation of ventilation surrogates computed from inspiratory and expiratory breath-hold CT with hyperpolarized Helium-3 & Xenon-129 MRI in a cohort of lung cancer patients. Methods: 5 patients underwent expiration & inspiration breath-hold CT. Xenon-129 & {sup 1}H MRI were also acquired at the same inflation state as inspiratory CT. This was followed immediately by acquisition of Helium-3 & {sup 1}H MRI in the same breath and at the same inflation state as inspiratory CT. Expiration CT was deformably registered to inspiration CT for calculation of ventilation CT from voxel-wise differences in Hounsfield units. Inspiration CT and the Xenon-129’s corresponding anatomical {sup 1}H MRI were registered to Helium-3 MRI via the same-breath anatomical {sup 1}H MRI. This enabled direct comparison of CT ventilation with Helium-3 MRI & Xenon-129 MRI for the median values in corresponding regions of interest, ranging from finer to coarser in-plane dimensions of 10 by 10, 20 by 20, 30 by 30 and 40 by 40, located within the lungs as defined by the same-breath {sup 1}H MRI lung mask. Spearman coefficients were used to assess voxel-level correlation. Results: The median Spearman’s coefficients of ventilation CT with Helium-3 & Xenon-129 MRI for ROIs of 10 by 10, 20 by 20, 30 by 30 and 40 by 40 were 0.52, 0.56, 0.60 and 0.68 and 0.40, 0.42, 0.52 and 0.70, respectively. Conclusion: This work demonstrates a method of acquiring CT & hyperpolarized gas MRI (Helium-3 & Xenon-129 MRI) in similar breath-holds to enable direct spatial comparison of ventilation maps. Initial results show moderate correlation between ventilation CT & hyperpolarized gas MRI, improving for coarser regions which could be attributable to the inherent noise in CT intensity, non-ventilatory effects and registration errors at the voxel-level. Thus, it may be more beneficial to quantify ventilation at a more regional level.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2012

Measuring Residential Ventilation System Airflows: Part 1 – Laboratory Evaluation of Airflow Meter Devices

Building codes increasingly require tighter homes and mechanical ventilation per ASHRAE Standard 62.2. These ventilation flows must be measured so that energy is not wasted with over ventilation and occupants’ health is not compromised by under ventilation. Flow hoods are used to measure these ventilation flows, but there is currently no standard specifying the measurement procedure and measurement devices that should be used. This study evaluates the accuracy of six commercially available flow hoods under laboratory conditions configured to emulate a residential mechanical ventilation duct system. The measurements taken with the flow hoods were compared to simultaneous measurements taken by an in-line reference flow meter having a known uncertainty. Results indicate that powered flow hoods yield more accurate measurements than non-powered flow hoods, and that a majority of the flow hoods measured inlet flows more accurately than outlet flows. In several cases, there was little resemblance between the manufacturers’ stated accuracy and the accuracy we found in our laboratory measurements. It is clear that current flow hood calibration procedures may not consider field application variables such as flow asymmetry, flow angle, and flow direction. A new flow hood measurement standard that takes these ‘real world’ conditions into account should be developed to ensure that residential buildings receive the intended ventilation flows.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2012

Measuring Residential Ventilation System Airflows: Part 1 – Laboratory Evaluation of Airflow Meter Devices

Building codes increasingly require tighter homes and mechanical ventilation per ASHRAE Standard 62.2. These ventilation flows must be measured so that energy is not wasted with over ventilation and occupants’ health is not compromised by under ventilation. Flow hoods are used to measure these ventilation flows, but there is currently no standard specifying the measurement procedure and measurement devices that should be used. This study evaluates the accuracy of six commercially available flow hoods under laboratory conditions configured to emulate a residential mechanical ventilation duct system. The measurements taken with the flow hoods were compared to simultaneous measurements taken by an in-line reference flow meter having a known uncertainty. Results indicate that powered flow hoods yield more accurate measurements than non-powered flow hoods, and that a majority of the flow hoods measured inlet flows more accurately than outlet flows. In several cases, there was little resemblance between the manufacturers’ stated accuracy and the accuracy we found in our laboratory measurements. It is clear that current flow hood calibration procedures may not consider field application variables such as flow asymmetry, flow angle, and flow direction. A new flow hood measurement standard that takes these ‘real world’ conditions into account should be developed to ensure that residential buildings receive the intended ventilation flows.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2018

Waste Encapsulation and Storage Facility Stabilization and Ventilation Project-18121

Department of Energy contractor CH2M HILL Plateau Remediation Company (CH2M) is responsible for the safe and compliant operation of the Waste Encapsulation and Storage Facility (WESF), a nuclear materials storage facility at Hanford containing 1,936 highly radioactive capsules containing cesium and strontium. The capsules are currently stored under approximately 4 m (13 ft) of water. The water shields workers from radiation and helps cool the capsules. WESF is a large, concrete structure nominally 48 m (160 ft) long, 30 m (98 ft) wide and 12 m (40 ft) high with the pool cells being approximately 4 m (13 ft) below grade level. It is a robust facility with walls ranging from 0.3 m to 1 m (1 ft to 3 ft) thick. While the capsules are currently in a safe configuration, WESF is an aging facility, and DOE and CH2M are modifying the facility to ensure continued safe and compliant operations and to support the eventual transfer of capsules to dry storage. Dry storage would eliminate the possibility of a release of radioactive material in the unlikely event of a major earthquake that might result in loss of pool storage water and overheating and breach of one or more capsules. The project was divided into two major deliverables: 1) Ventilation: replacement of the existing ventilation system which included a below-grade high efficiency particulate air (HEPA) filter pit with an above grade HEPA filter skid and new fans and ducting. 2) Stabilization: grouting deactivated facility hot cells and other void spaces to the maximum extent practical to reduce material at risk from legacy contamination. The aging ventilation system relied on HEPA filters that exceeded their operational life. Due to the high levels of radionuclide contamination, replacing the filters was impractical and highly hazardous. CH2M installed a new ventilation system to provide safe and compliant ventilation for future operations. The project used an existing, unused ventilation skid that was designed for another project. Repurposing the unused skid presented additional technical challenges to modify the system for the project specific requirements. The new system is above ground, easier to maintain and is built to current standards. New connections inside the facility were installed to allow the new ventilation to operate effectively. The stabilization project is unique in that core drilling and grouting was performed in an operating Hazard Category 2 nuclear facility, which brought forth safety basis and environmental regulatory challenges. The hot cells were isolated from all existing support utilities including electrical, process chemicals, manipulator ports, instrument air, etc. to seal the hot cells and prevent highly contaminated supernate or grout from leaking into adjacent galleries. A high flow grout was used to maximize the distance between injection ports. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2015

Building America Case Study: Sealed Crawl Spaces with Integrated Whole-House Ventilation in a Cold Climate, Ithaca, New York

"9One method of code-compliance for crawlspaces is to seal and insulate the crawlspace, rather than venting to the outdoors. However, codes require mechanical ventilation; either via conditioned supply air from the HVAC system, or a continuous exhaust ventilation strategy. As the CARB's building partner, Ithaca Neighborhood Housing Services, intended to use the unvented crawlspace in a recent development, CARB was interested in investigating a hybrid ventilation method that includes the exhaust air from the crawlspace as a portion of an ASHRAE 62.2 compliant whole-house ventilation strategy. This hybrid ventilation method was evaluated through a series of long-term monitoring tests that observed temperature, humidity, and pressure conditions through the home and crawlspace. Additionally, CARB worked with NREL to perform multi-point tracer gas testing on six separate ventilation strategies - varying portions of 62.2 required flow supplied by the crawlspace fan and an upstairs bathroom fan. The intent of the tracer gas testing was to identify effective Reciprocal Age of Air (RAoA), which is equivalent to the air change rate in well-mixed zones, for each strategy while characterizing localized infiltration rates in several areas of the home.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2016

WE-AB-202-05: Validation of Lung Stress Maps for CT-Ventilation Imaging

Purpose: To date, lung CT-ventilation imaging has been based on quantification of local breathing-induced changes in Hounsfield Units (HU) or volume. This work investigates the use of a stress map resulting from a biomechanical deformable image registration (DIR) algorithm as a metric of the ventilation function. Method: Eight lung cancer patients presenting different kinds of ventilation defects were retrospectively analyzed. Additionally, to the 4DCT acquired for radiotherapy planning, five of them had PET and three had SPECT imaging following inhalation of Ga-68 and Tc-99m, respectively. For each patient, the inhale phase of the 4DCT was registered to the exhale phase using Morfeus, a biomechanical DIR algorithm based on the determination of boundary conditions on the lung surfaces and vessel tree. To take into account the heterogeneity of the tissue stiffness in the stress map estimation, each tetrahedral element of the finite-element model was assigned a Young’s modulus ranging from 60kPa to 12MPa, as a function of the HU in the inhale CT. The node displacements and element stresses resulting from the numerical simulation were used to generate three CT-ventilation maps based on: (i) volume changes (Jacobian determinant), (ii) changes in HU, (iii) the maximum principal stress. The voxel-wise correlation between each CT-ventilation map and the PET or SPECT V image was computed in a lung mask. Results: For patients with PET, the mean (min-max) Spearman correlation coefficients r were: 0.33 (0.19–0.45), 0.36 (0.16–0.51) and 0.42 (0.21–0.59) considering the Jacobian, changes in HU and maximum principal stress, respectively. For patients with SPECT V, the mean r were: 0.12 (−0.12–0.43), 0.29 (0.22–0.45) and 0.33 (0.25–0.39). Conclusion: The maximum principal stress maps showed a stronger correlation with the ventilation images than the previously proposed Jacobian or change in HU maps. This metric thus appears promising for CT-ventilation imaging. This work was funded in part by NIH P01CA059827.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2024

Existence of a Nonzero Worst‐Case ACH for Short‐Term Exposure in Ventilated Indoor Spaces

A well‐ventilated room is essential to reduce the risk of airborne transmission. As such, the scientific community sets minimum limits on ventilation with the idea that increased ventilation reduces pathogen concentration and thus reduces the risk of transmission. In contrast, the upper limit on ventilation is usually determined by human comfort and the need to reduce energy consumption. While average pathogen concentration decreases with increased ventilation, local concentration depends on multiple factors and may not follow the same trend, especially within short exposure times over large separation distances. Here, we show through experiments and high‐fidelity simulations the existence of a worst‐case ventilation where local pathogen concentration increases near the receiving host. This occurs during the type of meetings that were recommended during the pandemic (and in some cases solely authorized) with reduced occupancy adhering to social distancing and short exposure times below 20 minutes. We maintain that for cases of high occupancy and long exposure time, increased ventilation remains necessary.

Construction & Building Technology↗
DOE OSTI2014

Indoor Air Quality and Ventilation in Residential Deep Energy Retrofits

Because airtightening is a significant part of Deep Energy Retrofits (DERs), concerns about ventilation and Indoor Air Quality (IAQ) have emerged. To investigate this, ventilation and IAQ were assessed in 17 non-smoking California Deep Energy Retrofit homes. Inspections and surveys were used to assess household activities and ventilation systems. Pollutant sampling performed in 12 homes included six-day passive samples of nitrogen dioxide (NO 2 ), formaldehyde and air exchange rate (AER); time-resolved data loggers were used to measure particle counts. Half of the homes provided continuous mechanical ventilation. Despite these homes being twice as airtight (3.0 and 7.6 ACH50, respectively), their median AER was indistinguishable from naturally vented homes (0.36 versus 0.37 hr -1 ). Numerous problems were found with ventilation systems; however, pollutant levels did not reach levels of concern in most homes. Ambient NO 2 standards were exceeded in some gas cooking homes that used legacy ranges with standing pilots, and in Passive House-style homes without range hoods exhausted to outside. Cooking exhaust systems were installed and used inconsistently. The majority of homes reported using low-emitting materials, and formaldehyde levels were approximately half those in conventional new CA homes (19.7 versus 36 μg/m 3 ), with emissions rates nearly 40percent less (12.3 versus 20.6 μg/m 2 /hr.). Presence of air filtration systems led to lower indoor particle number concentrations (PN >0.5 : 8.80E+06 PN/m 3 versus 2.99E+06; PN >2.5 : 5.46E+0.5 PN/m 3 versus 2.59E+05). The results indicate that DERs can provide adequate ventilation and IAQ, and that DERs should prioritize source control, particle filtration and well-designed local exhaust systems, while still providing adequate continuous ventilation.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2025

Hardware-in-Loop Modules for Testing Automated Ventilator Controllers

Automated ventilator controllers have the potential to simplify oxygen and carbon dioxide management for trauma. In the pre-hospital or military medicine environment, trauma care can be required for prolonged periods by personnel with limited ventilator management training. As such, there is a need for closed-loop control systems that can adapt ventilator management to a complex, ever-changing medical environment. Here, we present a novel hardware-in-loop test platform for the independent troubleshooting and evaluation of oxygen and carbon dioxide automated ventilator management capabilities. The oxygen management system provides an analogue blood oxygen signal that is responsive to the fraction of inspired oxygen and the peak inspiratory pressure ventilator settings. A tested oxygenation controller successfully reached the target oxygen saturation within 5 min. The carbon dioxide removal system integrates with commercial ventilator technology and mimics carbon dioxide generation, lung compliance, and airway resistance while providing an end-tidal carbon dioxide level that is responsive to changes in the tidal volume and respiratory rate settings. A test mechanical ventilator controller was able to regulate EtCO2 regardless of the starting value within 10 min. This highlights the system’s functionality and provides proof-of-concept demonstrations for how the hardware-in-loop test platforms can be used for evaluating closed-loop controller technologies.

Berard, David (ORCID:0000000322863846)↗
NASA NTRS2010

Regenerative Blower for EVA Suit Ventilation Fan

Portable life support systems in future space suits will include a ventilation subsystem driven by a dedicated fan. This ventilation fan must meet challenging requirements for pressure rise, flow rate, efficiency, size, safety, and reliability. This paper describes research and development that showed the feasibility of a regenerative blower that is uniquely suited to meet these requirements. We proved feasibility through component tests, blower tests, and design analysis. Based on the requirements for the Constellation Space Suit Element (CSSE) Portable Life Support System (PLSS) ventilation fan, we designed the critical elements of the blower. We measured the effects of key design parameters on blower performance using separate effects tests, and used the results of these tests to design a regenerative blower that will meet the ventilation fan requirements. We assembled a proof-of-concept blower and measured its performance at sub-atmospheric pressures that simulate a PLSS ventilation loop environment. Head/flow performance and maximum efficiency point data were used to specify the design and operating conditions for the ventilation fan. We identified materials for the blower that will enhance safety for operation in a lunar environment, and produced a solid model that illustrates the final design. The proof-of-concept blower produced the flow rate and pressure rise needed for the CSSE ventilation subsystem while running at 5400 rpm, consuming only 9 W of electric power using a non-optimized, commercial motor and controller and inefficient bearings. Scaling the test results to a complete design shows that a lightweight, compact, reliable, and low power regenerative blower can meet the performance requirements for future space suit life support systems.

Izenson, Michael G.↗
NASA NTRS2023

Ventilation Heat Exchanger / Flow Meter for xPLSS

The flow meter / heat exchanger (FMHX) in the ventilation loop of the exploration EMU cools the ventilation gas and measures the ventilation flow rate. The heat exchanger transfers heat from the ventilation gas to the thermal control loop via a miniature shell-and-tube heat exchanger. The flow meters calculate the flow rate of gas through the ventilation loop based on the pressure drop across the heat exchanger core. Creare has delivered four design validation test (DVT) heat exchangers and five DVT flow meters to NASA JSC to support development of the exploration portable life support system (xPLSS). This paper describes the design and performance of the DVT units.The heat exchangers are designed to cool the ventilation gas to a specified temperature with low pressure losses under the most challenging operating conditions. The measured performance of the DVT heat exchangers agrees well with design models and meets all performance requirements. The flow meters use a MEMS thermal flow sensor to produce a signal that is proportional to a small bypass flow around the heat exchanger core. They are designed to achieve high measurement accuracy across the full range of xPLSS operating conditions. We calibrated the flow meters in a special-purpose flow facility that simulates operation in the xPLSS ventilation loop. Calibration testing shows that DVT flow meters produce digital output for vent loop mass flow that meets NASA’s accuracy requirements across the range of xPLSS operating conditions. This paper reviews the design of the heat exchangers and flow meters and presents data from the final flow meter calibration testing, heat exchanger performance validation, and initial ground testing in NASA’s xPLSS.

spacesuit↗
NASA NTRS2023

Ventilation Heat Exchanger / Flow Meter for xPLSS

The flow meter / heat exchanger (FMHX) in the ventilation loop of the exploration EMU cools the ventilation gas and measures the ventilation flow rate. The heat exchanger transfers heat from the ventilation gas to the thermal control loop via a miniature shell-and-tube heat exchanger. The flow meters calculate the flow rate of gas through the ventilation loop based on the pressure drop across the heat exchanger core. Creare has delivered four design validation test (DVT) heat exchangers and five DVT flow meters to NASA JSC to support development of the exploration portable life support system (xPLSS). This paper describes the design and performance of the DVT units.The heat exchangers are designed to cool the ventilation gas to a specified temperature with low pressure losses under the most challenging operating conditions. The measured performance of the DVT heat exchangers agrees well with design models and meets all performance requirements. The flow meters use a MEMS thermal flow sensor to produce a signal that is proportional to a small bypass flow around the heat exchanger core. They are designed to achieve high measurement accuracy across the full range of xPLSS operating conditions. We calibrated the flow meters in a special-purpose flow facility that simulates operation in the xPLSS ventilation loop. Calibration testing shows that DVT flow meters produce digital output for vent loop mass flow that meets NASA’s accuracy requirements across the range of xPLSS operating conditions. This paper reviews the design of the heat exchangers and flow meters and presents data from the final flow meter calibration testing, heat exchanger performance validation, and initial ground testing in NASA’s xPLSS.

spacesuit↗
DOE OSTI2014

Optimization of Ventilation Energy Demands and Indoor Air Quality in High-Performance Homes

High-performance homes require that ventilation energy demands and indoor air quality (IAQ) be simultaneously optimized. We attempted to bridge these two areas by conducting tests in a research house located in Oak Ridge, TN, that was 20 months old, energy-efficient (i.e., expected to consume 50% less energy than a house built per the 2006 IRC), tightly-built (i.e., natural ventilation rate ~0.02 h-1), unoccupied, and unfurnished. We identified air pollutants of concern in the test home that could generally serve as indicators of IAQ, and conduced field experiments and computer simulations to determine the effectiveness and energy required by various techniques that lessened the concentration of these contaminants. Formaldehyde was selected as the main pollutant of concern among the contaminants that were sampled in the initial survey because it was the only compound that showed concentrations that were greater than the recommended exposure levels. Field data indicate that concentrations were higher during the summer primarily because emissions from sources rise with increases in temperature. Furthermore, supply ventilation and gas-phase filtration were effective means to reduce formaldehyde concentrations; however, exhaust ventilation had minimal influence on this pollutant. Results from simulations suggest that formaldehyde concentrations obtained while ventilating per ASHRAE 62.2-2010 could be decreased by about 20% from May through September through three strategies: 1) increasing ASHRAE supply ventilation by a factor of two, 2) reducing the thermostat setpoint from 76 to 74 F, or 3) running a gas-phase filtration system while decreasing supply ventilation per ASHRAE by half. In the mixed-humid climate of Oak Ridge, these strategies caused increases in electricity cost of ~$5 to ~$15/month depending on outdoor conditions.

Hun, Diana E↗
DOE OSTI2020

Residential Ventilation Systems

US homes are increasingly being provided with mechanical ventilation systems that are intended to comply with ASHRAE Standard 62.2. As mechanical ventilation is becoming more prevalent, the industry is gaining knowledge about measured installed performance of mechanical ventilation systems and guidance on how to avoid problem installations. Feedback from industry and research studies has led to several key improvements to the ASHRAE standard giving ventilation system designers more flexibility and providing more energy efficient ventilation solutions. This article summarizes some of the key advances in residential ventilation as well as the results of field investigations of residential ventilation system commissioning and operation/maintenance issues, much of which is from the USDOE Building America program.

Lubliner, Michael↗
DOE OSTI2014

Measure Guideline: Selecting Ventilation Systems for Existing Homes

This document addresses adding -or improving - mechanical ventilation systems to existing homes. The purpose of ventilation is to remove contaminants from homes, and this report discusses where, when, and how much ventilation is appropriate in a home, including some discussion of relevant codes and standards. Advantages, disadvantages, and approximate costs of various system types are presented along with general guidelines for implementing the systems in homes. CARB intends for this document to be useful to decision makers and contractors implementing ventilation systems in homes. Choosing the "best" system is not always straightforward; selecting a system involves balancing performance, efficiency, cost, required maintenance, and several other factors. It is the intent of this document to assist contractors in making more informed decisions when selecting systems. Ventilation is an integral part of a high-performance home. With more air-sealed envelopes, a mechanical means of removing contaminants is critical for indoor environmental quality and building durability.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2014

Building America Case Study: Selecting Ventilation Systems for Existing Homes (Fact Sheet)

This document addresses adding -or improving - mechanical ventilation systems to existing homes. The purpose of ventilation is to remove contaminants from homes, and this report discusses where, when, and how much ventilation is appropriate in a home, including some discussion of relevant codes and standards. Advantages, disadvantages, and approximate costs of various system types are presented along with general guidelines for implementing the systems in homes. CARB intends for this document to be useful to decision makers and contractors implementing ventilation systems in homes. Choosing the "best" system is not always straightforward; selecting a system involves balancing performance, efficiency, cost, required maintenance, and several other factors. It is the intent of this document to assist contractors in making more informed decisions when selecting systems. Ventilation is an integral part of a high-performance home. With more air-sealed envelopes, a mechanical means of removing contaminants is critical for indoor environmental quality and building durability.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2020

A Novel Simulation-Based Framework for Sensor Error Impact Analysis in Smart Building Systems: A Case Study for a Demand-Controlled Ventilation System

Sensors are one of the fundamental components for sensor-rich controls in buildings but are prone to different errors. Existing studies show that sensor errors hold a place among top-priority faults in building systems. Before we take countermeasures to mitigate the sensor errors, it is vital to prioritize key sensors and quantify the collective impacts of concurrent sensor errors. In response to this, a simulation-based methodology is introduced to conduct a comprehensive sensor error impact analysis in building systems, which adds a stochastic sensor prioritization through a sensitivity analysis on top of a commonly used deterministic sensor error quantification. The synergies of these two parts help better interpret the sensor error impacts on building energy consumption, ventilation performance, thermal comfort, etc. A sensor-rich CO2-based Demand-Controlled Ventilation system is used as a case study to demonstrate the viability of the methodology as a proof-of-the-concept. The results show that the energy savings potential and ventilation performance are mostly influenced by the accuracy of the AHU outdoor airflow sensors. The accuracy of zone level airflow sensors has a negligible impact on both energy savings and ventilation performance. The accuracy of zone CO2 sensors has more influence on the ventilation performance compared with the accuracy of zone airflow sensors. Compared with the baseline case with zero errors, the largest deviation percentages could reach 16.90% and 94.32%, respectively, in terms of the Heating, Ventilation, and Air-Conditioning (HVAC) annual energy consumption and the Outdoor Air Ratio (OAR) when multiple key sensors suffer from normal error intensities simultaneously.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗