Michael Spears

Association of Classroom Ventilation with Reduced Illness Absence: A Prospective Study in California Elementary Schools

Abstract Limited evidence associates inadequate classroom ventilation rates (VRs) with increased illness absence (IA). We investigated relationships between VRs and IA in California elementary schools over two school years in 162 3rd–5th‐grade classrooms in 28 schools in three school districts: South Coast (SC), Bay Area (BA), and Central Valley (CV). We estimated relationships between daily IA and VR (estimated from two year daily real‐time carbon dioxide in each classroom) in zero‐inflated negative binomial models. We also compared IA benefits and energy costs of increased VRs. All school districts had median VRs below the 7.1 l/s‐person California standard. For each additional 1 l/s‐person of VR, IA was reduced significantly (p<0.05) in models for combined districts (−1.6%) and for SC (−1.2%), and nonsignificantly for districts providing less data: BA (−1.5%) and CV (−1.0%). Assuming associations were causal and generalizable, increasing classroom VRs from the California average (4 l/s‐person) to the State standard would decrease IA by 3.4%, increase attendance‐linked funding to schools by

NATURAL GAS VARIABILITY IN CALIFORNIA: ENVIRONMENTAL IMPACTS AND DEVICE PERFORMANCE EXPERIMENTAL EVALUATION OF POLLUTANT EMISSIONS FROM RESIDENTIAL APPLIANCES

33 million annually, and increase costs by only

Improving Ventilation and Saving Energy: Final Report on Indoor Environmental Quality and Energy Monitoring in Sixteen Relocatable Classrooms

4 million. Further increasing VRs would provide additional benefits. These findings, while requiring confirmation, suggest that increasing classroom VRs above the State standard would substantially decrease illness absence and produce economic benefits.

A simulation of Local Power Distribution control strategies

The effect of liquefied natural gas on pollutant emissions was evaluated experimentally with used and new appliances in the laboratory and with appliances installed in residences, targeting information gaps from previous studies. Burner selection targeted available technologies that are projected to comprise the majority of installed appliances over the next decade. Experiments were conducted on 13 cooktop sets, 12 ovens, 5 broiler burners, 5 storage water heaters, 4 forced air furnaces, 1 wall furnace, and 6 tankless water heaters. Air-free concentrations and fuel-based emission factors were determined for carbon monoxide, nitrogen oxides, nitrogen dioxide, and the number of (predominantly ultrafine) particles over complete burns?including transient effects (device warm-up and intermittent firing of burners) following ignition--and during more stable end-of-burn conditions. Formaldehyde was measured over multi-burn cycles. The baseline fuel was Northern California line gas with Wobbe number (a measure of fuel energy delivery rate) of 1320-1340; test fuels had Wobbe numbers of roughly 1390 and 1420, and in some cases 1360. No ignition or operational problems were observed during test fuel use. Baseline emissions varied widely across and within burner groups and with burner operational mode. Statistically significant emissions changes were observed for some pollutants on some burners.

A Formaldehyde Exposure Assessment Tool for Occupants of FEMA Temporary Housing Units

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 36percent to 42percent across Californias climate zones, relative to 10 SEER units. Classroom ventilation was vastly improved as evidenced by far lower indoor minus outdoor CO2 concentrations. The IHPAC 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 57percent relative to the levels in the 10 SEER classrooms. The average IHPAC to 10 SEER formaldehyde ratio was about 67percent, indicating only a 33percent 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

Indoor Air Quality Assessment of the San Francisco Federal Building

0.15/kWh, the perclassroom range of savings is from about

Development and Field-Testing of a Study Protocol, including a Web-Based Occupant Survey Tool, for Use in Intervention Studies of Indoor Environmental Quality

85 to

Improving Ventilation and Saving Energy: Relocatable ClassroomField Study Interim Report

195 per year in California, and about

Indoor Environmental Quality Benefits of Apartment Energy Retrofits

89 to

Intake fractions of primary conserved air pollutants emitted from on-road vehicles in the United States

250 per year in the U.S., depending upon the city. These models did 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.