David Faulkner

University of California, Berkeley, Berkeley, California, United States

Are you David Faulkner?

Claim your profile

Publications (66)83.97 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: To assess cool-roof benefits, the temperatures, heat flows, and energy uses in two similar single-family, single-story homes built side by side in Fresno, California were measured for a year. The "cool" house had a reflective cool concrete tile roof (initial albedo 0.51) with above-sheathing ventilation, and nearly twice the thermal capacitance of the standard dark asphalt shingle roof (initial albedo 0.07) on the "standard" house. Cool-roof energy savings in the cooling and heating seasons were computed two ways. Method A divides by HVAC efficiency the difference (standard cool) in ceiling + duct heat gain. Method B measures the difference in HVAC energy use, corrected for differences in plug and window heat gains. Based on the more conservative Method B, annual cooling (compressor + fan), heating fuel, and heating fan site energy savings per unit ceiling area were 2.82 kWh/m(2) (26%), 1.13 kWh/m(2) (4%), and 0.0294 kWh/m(2) (3%), respectively. Annual space conditioning (heating + cooling) source energy savings were 10.7 kWh/m(2) (15%); annual energy cost savings were $0.886/m(2) (20%). Annual conditioning CO2, NOx, and SO2 emission reductions were 1.63 kg/m(2) (15%), 0.621 g/m(2) (10%), and 0.0462 g/m(2) (22%). Peak-hour cooling power demand reduction was 0.88 W/m(2) (37%).
    No preview · Article · Sep 2014 · Energy and Buildings
  • D H Bennett · W Fisk · M G Apte · X Wu · A Trout · D Faulkner · D Sullivan
    [Show abstract] [Hide abstract]
    ABSTRACT: Abstract This field study of 37 small and medium commercial buildings throughout California obtained information on ventilation rate, temperature, and heating, ventilating, and air-conditioning (HVAC) system characteristics. The study included seven retail establishments; five restaurants; eight offices; two each of gas stations, hair salons, healthcare facilities, grocery stores, dental offices, and fitness centers; and five other buildings. Fourteen (38%) of the buildings either could not or did not provide outdoor air through the HVAC system. The air exchange rate averaged 1.6 (s.d. = 1.7) exchanges per hour and was similar between buildings with and without outdoor air supplied through the HVAC system, indicating that some buildings have significant leakage or ventilation through open windows and doors. Not all buildings had sufficient air exchange to meet ASHRAE 62.1 Standards, including buildings used for fitness centers, hair salons, offices, and retail establishments. The majority of the time, buildings were within the ASHRAE temperature comfort range. Offices were frequently overcooled in the summer. All of the buildings had filters, but over half the buildings had a filter with a minimum efficiency reporting value rating of 4 or lower, which are not very effective for removing fine particles. Most U.S. commercial buildings (96%) are small- to medium-sized, using nearly 18% of the country’s energy, and sheltering a large population daily. Little is known about the ventilation systems in these buildings. This study found a wide variety of ventilation conditions, with many buildings failing to meet relevant ventilation standards. Regulators may want to consider implementing more complete building inspections at commissioning and point of sale.
    No preview · Article · Jan 2012 · Indoor Air

  • No preview · Article · Jan 2011 · Epidemiology
  • William J. Fisk · David Faulkner · Douglas P. Sullivan
    [Show abstract] [Hide abstract]
    ABSTRACT: Are the carbon dioxide (CO2) sensors in your demand controlled ventilation systems sufficiently accurate? The data from these sensors are used to automatically modulate minimum rates of outdoor air ventilation. The goal is to keep ventilation rates at or above design requirements while adjusting the ventilation rate with changes in occupancy in order to save energy. Studies of energy savings from demand controlled ventilation and of the relationship of indoor CO2 concentrations with health and work performance provide a strong rationale for use of indoor CO2 data to control minimum ventilation rates1-7. However, this strategy will only be effective if, in practice, the CO2 sensors have a reasonable accuracy. The objective of this study was; therefore, to determine if CO2 sensor performance, in practice, is generally acceptable or problematic. This article provides a summary of study methods and findings ? additional details are available in a paper in the proceedings of the ASHRAE IAQ?2007 Conference8.
    No preview · Article · Oct 2008
  • William Fisk · David Faulkner · Douglas P. Sullivan
    [Show abstract] [Hide abstract]
    ABSTRACT: Carbon dioxide (CO2) sensors are often deployed in commercial buildings to obtain CO2 data that are used to automatically modulate rates of outdoor air supply. The goal is to keep ventilation rates at or above design requirements and to save energy by avoiding ventilation rates exceeding design requirements. However, there have been many anecdotal reports of poor CO2 sensor performance in actual commercial building applications. This study evaluated the accuracy of 44 CO2 sensors located in nine commercial buildings to determine if CO2 sensor performance, in practice, is generally acceptable or problematic. CO2 measurement errors varied widely and were sometimes hundreds of parts per million. Despite its small size, this study provides a strong indication that the accuracy of CO2 sensors, as they are applied and maintained in commercial buildings, is frequently less than needed to measure typical values of maximum one-hour-average indoor-outdoor CO2 concentration differences with less than a 20percent error. Thus, we conclude that there is a need for more accurate CO2 sensors and/or better sensor maintenance or calibration procedures.
    No preview · Article · Jan 2008
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: An improved HVAC system for portable classrooms was specified to address key problems in existing units. These included low energy efficiency, poor control of and provision for adequate ventilation, and excessive acoustic noise. Working with industry, a prototype improved heat pump air conditioner was developed to meet the specification. A one-year measurement-intensive field-test of ten of these IHPAC systems was conducted in occupied classrooms in two distinct California climates. These measurements are compared to those made in parallel in side by side portable classrooms equipped with standard 10 SEER heat pump air conditioner equipment. The IHPAC units were found to work as designed, providing predicted annual energy efficiency improvements of about 36 percent to 42 percent across California's climate zones, relative to 10 SEER units. Classroom ventilation was vastly improved as evidenced by far lower indoor minus outdoor CO2 concentrations. TheIHPAC units were found to provide ventilation that meets both California State energy and occupational codes and the ASHRAE minimum ventilation requirements; the classrooms equipped with the 10 SEER equipment universally did not meet these targets. The IHPAC system provided a major improvement in indoor acoustic conditions. HVAC system generated background noise was reduced in fan-only and fan and compressor modes, reducing the nose levels to better than the design objective of 45 dB(A), and acceptable for additional design points by the Collaborative on High Performance Schools. The IHPAC provided superior ventilation, with indoor minus outdoor CO2 concentrations that showed that the Title 24 minimum ventilation requirement of 15 CFM per occupant was nearly always being met. The opposite was found in the classrooms utilizing the 10 SEER system, where the indoor minus outdoor CO2 concentrations frequently exceeded levels that reflect inadequate ventilation. Improved ventilation conditions in the IHPAC lead to effective removal of volatile organic compounds and aldehydes, on average lowering the concentrations by 57 percent relative to the levels in the 10 SEER classrooms. The average IHPAC to 10 SEER formaldehyde ratio was about 67 percent, indicating only a 33 percent reduction of this compound in indoor air. The IHPAC thermal control system provided less variability in occupied classroom temperature than the 10 SEER thermostats. The average room temperatures in all seasons tended to be slightly lower in the IHPAC classrooms, often below the lower limit of the ASHRAE 55 thermal comfort band. State-wide and national energy modeling provided conservative estimates of potential energy savings by use of the IHPAC system that would provide payback a the range of time far lower than the lifetime of the equipment. Assuming electricity costs of $0.15/kWh, the perclassroom range of savings is from about $85 to $195 per year in California, and about $89 to $250 per year in the U.S., depending upon the city. These modelsdid not include the non-energy benefits to the classrooms including better air quality and acoustic conditions that could lead to improved health and learning in school. Market connection efforts that were part of the study give all indication that this has been a very successful project. The successes include the specification of the IHPAC equipment in the CHPS portable classroom standards, the release of a commercial product based on the standards that is now being installed in schools around the U.S., and the fact that a public utility company is currently considering the addition of the technology to its customer incentive program. These successes indicate that the IHPAC may reach its potential to improve ventilation and save energy in classrooms.
    Full-text · Article · Jan 2008
  • [Show abstract] [Hide abstract]
    ABSTRACT: Underfloor air distribution (UFAD) is a new method of supplying heated or cooled air throughout a building. Reported advantages of UFAD include energy savings and improved indoor air quality (IAQ). We measured several aspects of the performance of a UFAD system installed in a medium-size office building. The measured air change effectiveness was very close to unity, which is comparable to that measured in buildings with typical overhead air distribution. The pollutant removal efficiency for carbon dioxide was 13% higher than expected in a space with well-mixed air, suggesting a 13% reduction in exposures to occupant generated pollutants. The increase in indoor air temperatures with height above the floor was only 1 to 2 °C. This amount of thermal stratification could reduce the sensible energy requirements for cooling of outdoor air by approximately 10%. The occupants' level of satisfaction with thermal conditions was well above average and this high satisfaction rating could possibly be due, in all or part, to the use of a UFAD system. The results of this study provide some evidence of moderate energy and IAQ-related benefits of UFAD. Before general conclusions are drawn, the benefits need to be confirmed in other studies.
    No preview · Article · Dec 2006 · International Journal of Ventilation
  • William J. Fisk · David Faulkner · Douglas P. Sullivan
    [Show abstract] [Hide abstract]
    ABSTRACT: Approximately 1 quad (1 EJ) of energy, costing $7.2 billion, is used annually for conditioning the OA ventilation air supplied to U.S. commercial, institutional, and government, buildings. The rate of OA ventilation also affects occupant health. In cross-sectional studies of buildings with various rates of OA ventilation, lower ventilation rates have been associated with increased respiratory illnesses (e.g., common colds), increased sick building syndrome symptoms, and diminished satisfaction with IAQ. Recent data indicate that lower OA ventilation rates also are associated with small decrements in work performance. Clearly, a need exists to strike a balance between the benefits of increased OA ventilation and the beneficial energy savings from reduced OA ventilation. Design of the OA intake systems to avoid low pressure signals and the use of accurate pressure transducers are keys to accurate measurements of OA flow rate. With real-time data on OA flows, substantial improvements in our control of OA supply to buildings should be possible.
    No preview · Article · Aug 2006 · Ashrae Journal
  • William J. Fisk · David Faulkner · Douglas P. Sullivan
    [Show abstract] [Hide abstract]
    ABSTRACT: The rate of outdoor air (OA) supply affects building energy consumption, occupant health, and work performance; however, minimum ventilation rates are often poorly controlled. Real-time measurements of OA flow rates into HVAC systems would enable improved flow control. This article demonstrates that at least some of the available technologies for real-time measurement of OA air intake rate are reasonably accurate and provides guidance on how these technologies should be used.
    No preview · Article · Jul 2005 · Ashrae Journal
  • Source
    William J. Fisk · Olli Seppanen · David Faulkner · Joe Huang
    [Show abstract] [Hide abstract]
    ABSTRACT: This study estimated the health, energy, and economic benefits of an economizer ventilation control system that increases outside air supply during mild weather to save energy. A model of the influence of ventilation rate on airborne transmission of respiratory illnesses was used to extend the limited data relating ventilation rate with illness and sick leave. An energy simulation model calculated ventilation rates and energy use versus time for an office building in Washington, D.C. with fixed minimum outdoor air supply rates, with and without an economizer. Sick leave rates were estimated with the disease transmission model. In the modeled 72-person office building, our analyses indicate that the economizer reduces energy costs by approximately $2000 and, in addition, reduces sick leave. The annual financial benefit of the decrease in sick leave is estimated to be between $6,000 and $16,000. This modeling suggests that economizers are much more cost effective than currently recognized.
    Preview · Article · Jan 2005 · ASHRAE Transactions
  • William J. Fisk · David Faulkner · Douglas P. Sullivan
    [Show abstract] [Hide abstract]
    ABSTRACT: Although the rate of outdoor air (OA) ventilation has a substantial influence on building energy consumption and occupant health, the available data indicate the outdoor air ventilation rates are poorly controlled in many buildings. Technologies being marketed for real time measurement of the flow rates of outdoor air into HVAC systems should enable better control of OA ventilation. In laboratory research they have studied the performance of these technologies. Sources of measurement errors identified during conduct of this research include: low air speeds; high spatial variability in air speed and direction; large eddies downstream of outdoor air intake louvers; and backwards airflow through a portion of outdoor air dampers. Several suggestions for overcoming these sources of errors were developed including: design and control of the outdoor air intake system to avoid low, hard-to measure, air speeds; use of highly sensitive pressure and velocity sensors; measuring air speeds between blades of louvers, rather than downstream of louvers; smoothing out the airflow between the outdoor air louver and damper through proper louver selection and insertion of components to straighten air flow; and maintaining a pressure drop across the outdoor air damper that exceeds approximately 0.04 IWG (10 Pa).
    No preview · Article · Jan 2005 · ASHRAE Transactions
  • Source
    William J. Fisk · David Faulkner · Douglas P. Sullivan
    [Show abstract] [Hide abstract]
    ABSTRACT: During the last few years, new technologies have been introduced for real-time continuous measurement of the flow rates of outdoor air (OA) into HVAC systems; however, an evaluation of these measurements technologies has not previously been published. This document describes a test system and protocols developed for a controlled evaluation of these measurement technologies. The results of tests of three commercially available measurement technologies are also summarized. The test system and protocol were judged practical and very useful. The three commercially available measurement technologies should provide reasonably, e.g., 20%, accurate measurements of OA flow rates as long as air velocities are maintained high enough to produce accurately measurable pressure signals. In HVAC systems with economizer controls, to maintain the required air velocities the OA intake will need to be divided into two sections in parallel, each with a separate OA damper. All of the measurement devices had pressure drops that are likely to be judged acceptable. The influence of wind on the accuracy of these measurement technologies still needs to be evaluated.
    Preview · Article · Oct 2004 · ASHRAE Transactions
  • Source
    D G Shendell · Prill RP · W J Fisk · M G Apte · D Blake · D Faulkner
    [Show abstract] [Hide abstract]
    ABSTRACT: Student attendance in American public schools is a critical factor in securing limited operational funding. Student and teacher attendance influence academic performance. Limited data exist on indoor air and environmental quality (IEQ) in schools, and how IEQ affects attendance, health, or performance. This study explored the association of student absence with measures of indoor minus outdoor carbon dioxide concentration (dCO2). Absence and dCO 2 data were collected from 409 traditional and 25 portable classrooms from 22 schools located in six school districts in the states of Washington and Idaho. Study classrooms had individual heating, ventilation, and air conditioning (HVAC) systems, except two classrooms without mechanical ventilation. Classroom attributes, student attendance and school-level ethnicity, gender, and socioeconomic status (SES) were included in multivariate modeling. Forty-five percent of classrooms studied had short-term indoor CO 2 concentrations above 1000 p.p.m. A 1000 p.p.m. increase in dCO 2 was associated (P < 0.05) with a 0.5-0.9% decrease in annual average daily attendance (ADA), corresponding to a relative 10-20% increase in student absence. Annual ADA was 2% higher (P < 0.0001) in traditional than in portable classrooms.
    Full-text · Article · Oct 2004 · Indoor Air
  • Olli Seppanen · William J. Fisk · David Faulkner
    [Show abstract] [Hide abstract]
    ABSTRACT: Indoor temperature is one of the fundamental characteristics of the indoor environment. It can be controlled with different accuracy depending on the building and its HVAC system. The purpose of this study was to evaluate the potential benefits of improved temperature control, and apply the information for a cost-benefit analyses. The indoor temperature affects several human responses, including thermal comfort, perceived air quality, sick building syndrome symptoms and performance in work. In this study we focused on the effects of temperature on performance in work. We collected and analyzed the literature relating the performance in work and temperature. The results of multiple studies are relatively consistent and show an average relationship of 2% decrement in work performance per degree C when the temperature is above 25 C. Less data were available on the performance in low temperatures. However, studies show a strong effect on manual tasks with temperatures below thermal neutrality as soon as the temperature of hands decreased due to control of blood flow. When the estimated productivity decrement from elevated temperatures was applied to data from a study of night-time ventilative cooling, the estimated value of productivity improvements were 32 to 120 times greater than the cost of energy to run fans during the night.
    No preview · Article · Jun 2004 · ASHRAE Transactions
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Twenty-seven laboratory experiments were conducted in a simulated smoking room to quantify rates of environmental tobacco smoke (ETS) leakage to a nonsmoking area as a function of the physical and operational characteristics of the smoking room. Data are presented for the various types of leakage flows, the effect of these leaks on smoking room performance and nonsmoker exposure, and the relative importance of each leakage mechanism. The results indicate that the first priority for an effective smoking room is to maintain it depressurized with respect to adjoining nonsmoking areas. The amount of ETS pumped out by the smoking room door when it is opened and closed can be reduced significantly by substituting a sliding door for the standard swing-type door. An "open doorway" configuration used twice the ventilation flow of those with smoking room doors, but yielded less reduction in nonsmoker exposure. Measured results correlated well with results modeled with mass-balance equations (R(2) = 0.82-0.99). Most of these results are based on sulfur hexafluoride (SF(6)) tracer gas leakage. Because five measured ETS tracers showed good correlation with SF(6), these conclusions should apply to ETS leakage as well. Field tests of a designated smoking room in an office building qualitatively agreed with model predictions.
    Full-text · Article · Mar 2004 · Journal of Occupational and Environmental Hygiene
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We investigated the relationship between ventilation rates and individual work performance in a call center, and controlled for other factors of the indoor environment. We randomized the position of the outdoor air control dampers, and measured ventilation rate, differential (indoor minus outdoor) carbon dioxide (DeltaCO(2)) concentration, supply air velocity, temperature, humidity, occupant density, degree of under-staffing, shift length, time of day, and time required to complete two different work performance tasks (talking with clients and post-talk wrap-up to process information). DeltaCO(2) concentrations ranged from 13 to 611 p.p.m. We used multivariable regression to model the association between the predictors and the responses. We found that agents performed talk tasks fastest when the ventilation rate was highest, but that the relationship between talk performance and ventilation was not strong or monotonic. We did not find a statistically significant association between wrap-up performance and ventilation rate. Agents were slower at the wrap-up task when the temperature was high (> 25.4 degrees C). Agents were slower at wrap-up during long shifts and when the call center was under-staffed. PRACTICAL IMPLICATIONS: The productivity benefits of ventilation rates that exceed common standards such as ASHRAE Standard 62 may be small (0-2%), and other factors may have a larger impact on productivity. Understaffing and long shifts should be avoided because both showed a negative impact on performance. In this study, high temperature had the largest statistically significant impact on productivity and was caused by occupants fighting over the thermostat setpoint. Care should be taken to avoid high temperatures in call centers. If occupants are allowed to adjust temperature setpoints, then the size and/or duration of the setpoint change should be restricted.
    Full-text · Article · Feb 2004 · Indoor Air
  • Source
    D Faulkner · W J Fisk · D P Sullivan · S M Lee
    [Show abstract] [Hide abstract]
    ABSTRACT: In chamber experiments, we investigated the ventilation effectiveness and thermal comfort of a task ventilation system with an air supply nozzle located underneath the front edge of a desk and directing air towards a heated mannequin or a human volunteer seated at the desk. The task ventilation system provided outside air, while another ventilation system provided additional space cooling but no outside air. Test variables included the vertical angle of air supply (-15 degrees to 45 degrees from horizontal), and the supply flow rate of (3.5-6.5 l/s). Using the tracer gas step-up and step-down procedures, the measured air change effectiveness (i.e., exhaust air age divided by age of air in the breathing zone) in experiments with the mannequin ranged from 1.4 to 2.7 (median, 1.8), whereas with human subjects the air change effectiveness ranged from 1.3 to 2.3 (median, 1.6). The majority of the air change effectiveness values with the human subjects were less than values with the mannequin using comparable tests. Similarly, the tests run with supply air temperature equal to the room air temperature had lower air change effectiveness values than comparable tests with the supply air temperature lower ( approximately 5 degrees C) than the room air temperature. The air change effectiveness values are higher than typically reported for commercially-available task ventilation or displacement ventilation systems. Based on surveys completed by the subjects, operation of the task ventilation system did not cause thermal discomfort. PRACTICAL IMPLICATIONS: With a desk-edge-mounted task ventilation system it is possible to obtain an increase in the effective ventilation rate of 50%. This could lead to reduced energy use. Also, this improvement can be gained while maintaining thermal comfort for occupants. Thus occupants can be thermally comfortable and save energy at the same time.
    Preview · Article · Feb 2004 · Indoor Air
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A study of the relationship between outside air ventilation rate and concentrations of volatile organic compounds (VOCs) generated indoors was conducted in a call center office building. The building, with two floors and a total floor area of 4600 m2, is located in the San Francisco Bay Area, CA. Ventilation rates were manipulated with the building's four air handling units (AHUs). VOC and CO2 concentrations in the AHU returns were measured on 7 days during a 13-week period. VOC emission factors were determined for individual zones on days when they were operating at near steady-state conditions. The emission factor data were subjected to principal component (PC) analysis to identify groups of co-varying compounds. Potential sources of the PC vectors were ascribed based on information from the literature. The per occupant CO2 generation rates were 0.0068–0.0092 l s−1. The per occupant isoprene generation rates of 0.2–0.3 mg h−1 were consistent with the value predicted by mass balance from breath concentration and exhalation rate. The relationships between indoor minus outdoor VOC concentrations and ventilation rate were qualitatively examined for eight VOCs. Of these, acetaldehyde and hexanal, which likely were associated with material sources, and decamethylcyclopentasiloxane, associated with personal care products, exhibited general trends of higher concentrations at lower ventilation rates. For other compounds, a clear inverse relationship between VOC concentrations and ventilation was not observed. The net concentration of 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate isomers, examples of low-volatility compounds, changed very little with ventilation likely due to sorption and re-emission effects. These results illustrate that the efficacy of ventilation for controlling VOC concentrations can vary considerably depending upon the operation of the building, the pollutant sources and the physical and chemical processes affecting the pollutants. Thus, source control measures, in addition to adequate ventilation, are required to limit concentrations of VOCs in office buildings.
    Full-text · Article · Dec 2003 · Atmospheric Environment
  • [Show abstract] [Hide abstract]
    ABSTRACT: Smoking is allowed in specially designed and operated breakrooms that meet three criteria. First, air from the room is exhausted directly to the outside by an exhaust fan. Second, no smoking room air is recirculated to other parts of the building. Third, smoking rooms are in a non-work area where employees are not required to be present as part of their work responsibilities other than custodial or maintenance work when the room is unoccupied. Addressing criteria 1 and 2, this paper considers the level of negative pressurization and other separation techniques that are effective in achieving the "no air ⋯ is recirculated⋯" criteria of 2. Focus is on minimizing leakage of air from these breakrooms to non-smoking areas.
    No preview · Article · Jun 2003
  • William J. Fisk · David Faulkner · Jari Palonen · Olli Seppanen

    No preview · Article · Jun 2003

Publication Stats

923 Citations
83.97 Total Impact Points

Institutions

  • 1991-2014
    • University of California, Berkeley
      • Center for Environmental Design Research (CEDR)
      Berkeley, California, United States
  • 1997-2008
    • Lawrence Berkeley National Laboratory
      • Indoor Environment Group
      Berkeley, California, United States
  • 2000
    • Berkeley Earth
      Washington, Washington, D.C., United States