Estimated Savings from Turning Off Unnecessary Lights at the Langford Architecture Center During the 1996 Christmas Holidays

During the 1996 Christmas holidays the College of Architecture initiated a trial program to turn off unnecessary lights during unoccupied periods. This effort targeted the unnecessary lights in all studios, classrooms, labs and offices. Had those lights been left on, the building would have consumed 100 kW more electricity every hour. The total electricity savings was about 31,200 kWh over 13 days, which is equivalent to a total cost saving of $936.00. If the College continues to turn off unnecessary lights during unoccupied periods, the estimated annual cost savings would be$13,711, which is 40% of the target savings estimated in the test we performed earlier in 1996. Labor costs to accomplish a manual shutdown are approximately $96.00 per week. If this is deducted from the annual cost savings, the lighting turn-off program still saves about$8,632 per year

Thermal Comfort Study in a Naturally Ventilated Residential Building in a Tropical Hot-Humid Climate Region

This paper presents a thermal comfort study in a naturally ventilated residential building located in a tropical hot-humid climate region. The specific objective of this study is to investigate whether thermal comfort in this house can be achieved through a passive system only. The methods used in this study included conducting hourly monitoring of the temperature and relative humidity; measuring the air velocities; and assessing occupants' thermal sensations through questionnaires and interview. The data from the questionnaires were matched to the monitored data to assess the acceptable range of comfortable condition. Then using an hourly simulation program, some components of the building were also "modified" to investigate whether the building can be made "more comfortable". This study shows that it is possible to provide a thermally comfortable space in this region without using mechanical air-conditioning systems. The occupants' acceptable range of comfortable condition is different than that of people in the northern latitudes. The occupants sensed "neutrality" when the operative temperature in the house was about 27 degree Celsius (80°F). The occupants could also tolerate slightly warm conditions, that is up to 29 degree Celsius (84OF), and still never wanted to install any air-conditioning systems. The simulation showed that using light wall materials would result in cooler indoor temperature at night but warmer during the day. If all windows were opened (25% the total floor area) the house could be more comfortable at night but less comfortable during the day. Findings of this study are important for architects and engineers in designing comfortable living spaces in these regions

A Calibration Methodology for Retrofit Projects Using Short-Term Monitoring and Disaggregated Energy Use Data

This paper presents an improved methodology to calibrate energy simulation models to better represent the actual energy use breakdowns in existing buildings. The goal of this methodology is to help architects and engineers accurately determine the current energy use and identify any energy-related problems in the building before proposing the retrofit design solutions, without conducting long-term monitoring. The methodology includes procedures to conduct systematic data collection, "on-off' tests to determine the power densities of the electrical loads, up to four weeks of building energy monitoring to derive the energy use profiles and temperature settings, and disaggregation of the measured energy use data. The procedures also utilize the monthly utility billing records and site weather data. The calibration to the measured data is done on both hourly and monthly basis. The procedures are built into a computer program and integrated with previously developed simulation software. The user interface of the program includes guidelines to help the user decide which simulation input variable has to be altered in order to match the measured data. It also produces graphical outputs to help in visualizing the results, and several guidelines to help study different retrofit strategies after the model has been calibrated

Effectiveness of External Window Attachments Based on Daylight Utilization and Cooling Load Reduction for Small Office Buildings in Hot Humid Climates

This study explored the effectiveness of selected external shading devices and glazing treatments used to minimize the total annual energy consumption in small office buildings in hot humid climates. The external shading devices included a permanent horizontal overhang and a light shelf. The selected types of glazing included clear, reflective, tinted, low-emissivity coating, and heat-mirror glass. One concern about using external window attachments is that while reducing the solar heat gains, they also reduce the amount of the daylight needed to supplement interior lighting. Therefore the objective of this study was to explore which strategy would give a balance between solar heat gain reduction and daylight utilization and result in the most energy savings in the building. Computer simulations using an hourly energy calculation model were conducted to predict the building's total energy consumption using each strategy. The economics of each strategy were analyzed with lifecycle costing techniques using the present value technique. Results show that properly designed overhangs that shade clear glazing are slightly more cost-effective than specialized low-e glazing systems. These results are unique for hot humid climates where winter heating is not an issue. On the contrary, when used in cold climates, external shading devices tend to increase the building's energy consumption

Lighting Survey Results at the Langford Architecture Center and Estimated Savings by Delamping

The results showed that the rooms that can be delamped are the studios, the computer labs at the ground floor of Building A, and most perimeter offices in Building A and C. The results also showed that, while the illuminance levels in some of the rooms were not high, the lighting power density was actually very high. This is caused by the type of the inefficient fixtures and the non energy-efficient lamps and ballasts that are currently installed. It was previously estimated that 30% of the current fixtures could be delamped, resulting in an estimated annual energy cost savings of $9,200. However, several other strategies should be included with the delamping, such as adding more task lighting, lowering the position of the indirect fixtures in the studios, replacing the current fixture covers, and changing the current lamps and ballasts with the energy-efficient lamps and ballasts.This report presents the results of a survey conducted to measure the illuminance levels in all rooms in the Langford Architecture Center buildings. The purpose of this survey was to investigate which rooms are over illuminated, and thus present a potential to be delamped. This survey was part of the investigation to determine the effective strategy to reduce the lighting electricity use in Langford Architecture Center

Estimated Savings from Turning Off Unnecessary Lights at the Langford Architecture Center During the 1996 Christmas Holidays

During the 1996 Christmas holidays the College of Architecture initiated a trial program to turn off unnecessary lights during unoccupied periods. This effort targeted the unnecessary lights in all studios, classrooms, labs and offices. Had those lights been left on, the building would have consumed 100 kW more electricity every hour. The total electricity savings was about 31,200 kWh over 13 days, which is equivalent to a total cost saving of $936.00. If the College continues to turn off unnecessary lights during unoccupied periods, the estimated annual cost savings would be$13,711, which is 40% of the target savings estimated in the test we performed earlier in 1996. Labor costs to accomplish a manual shutdown are approximately $96.00 per week. If this is deducted from the annual cost savings, the lighting turn-off program still saves about$8,632 per year

Estimated Savings from Turning Off Unnecessary Electrical Loads During Unoccupied Periods at the Langford Architecture Center

To achieve this saving, we first recommend that an energy awareness program be initiated. To implement this program, we suggest the following efforts: (1) conduct a more detailed analysis of all evening-time loads to determine which loads can be turned off without inconveniencing students or faculty/staff, (2) initiate a turn off program by hiring a student worker who would be responsible for turning off the lights in the studios and classrooms after midnight, (3) continue replacing the incandescent and 40W fluorescent fixtures with energy-efficient fixtures, (4) install high quality occupancy sensors in the studios and other rooms where cost justified. Finally, use the weekly monitoring by the Energy Systems Laboratory to track the progress and provide feedback to students and faculty/staff.This report presents the results of an on-off test conducted to determine the lighting load in the studios on the third and fourth floors of the Langford Architecture Center Building A and the savings that would be achieved by turning off the lights in those studios during unoccupied hours. Turning off the lights on the third and fourth floor studios would reduce the electricity cost by $4,757 per year and the associated heating and cooling costs by an additional$583 for a total savings of $5,340. If all unnecessary electrical loads could be turned off during the evening when not in use, as much as$34,200 per year could be saved at the Langford Architecture complex

Evaluating assumptions of scales for subjective assessment of thermal environments – Do laypersons perceive them the way, we researchers believe?

People's subjective response to any thermal environment is commonly investigated by using rating scales describing the degree of thermal sensation, comfort, and acceptability. Subsequent analyses of results collected in this way rely on the assumption that specific distances between verbal anchors placed on the scale exist and that relationships between verbal anchors from different dimensions that are assessed (e.g. thermal sensation and comfort) do not change. Another inherent assumption is that such scales are independent of the context in which they are used (climate zone, season, etc.). Despite their use worldwide, there is indication that contextual differences influence the way the scales are perceived and therefore question the reliability of the scales’ interpretation. To address this issue, a large international collaborative questionnaire study was conducted in 26 countries, using 21 different languages, which led to a dataset of 8225 questionnaires. Results, analysed by means of robust statistical techniques, revealed that only a subset of the responses are in accordance with the mentioned assumptions. Significant differences appeared between groups of participants in their perception of the scales, both in relation to distances of the anchors and relationships between scales. It was also found that respondents’ interpretations of scales changed with contextual factors, such as climate, season, and language. These findings highlight the need to carefully consider context-dependent factors in interpreting and reporting results from thermal comfort studies or post-occupancy evaluations, as well as to revisit the use of rating scales and the analysis methods used in thermal comfort studies to improve their reliability

The Scales Project, a cross-national dataset on the interpretation of thermal perception scales

Thermal discomfort is one of the main triggers for occupants’ interactions with components of the built environment such as adjustments of thermostats and/or opening windows and strongly related to the energy use in buildings. Understanding causes for thermal (dis-)comfort is crucial for design and operation of any type of building. The assessment of human thermal perception through rating scales, for example in post-occupancy studies, has been applied for several decades; however, long-existing assumptions related to these rating scales had been questioned by several researchers. The aim of this study was to gain deeper knowledge on contextual influences on the interpretation of thermal perception scales and their verbal anchors by survey participants. A questionnaire was designed and consequently applied in 21 language versions. These surveys were conducted in 57 cities in 30 countries resulting in a dataset containing responses from 8225 participants. The database offers potential for further analysis in the areas of building design and operation, psycho-physical relationships between human perception and the built environment, and linguistic analyses

The Scales Project, a cross-national dataset on the interpretation of thermal perception scales

Thermal discomfort is one of the main triggers for occupants' interactions with components of the built environment such as adjustments of thermostats and/or opening windows and strongly related to the energy use in buildings. Understanding causes for thermal (dis-)comfort is crucial for design and operation of any type of building. The assessment of human thermal perception through rating scales, for example in post-occupancy studies, has been applied for several decades; however, long-existing assumptions related to these rating scales had been questioned by several researchers. The aim of this study was to gain deeper knowledge on contextual influences on the interpretation of thermal perception scales and their verbal anchors by survey participants. A questionnaire was designed and consequently applied in 21 language versions. These surveys were conducted in 57 cities in 30 countries resulting in a dataset containing responses from 8225 participants. The database offers potential for further analysis in the areas of building design and operation, psycho-physical relationships between human perception and the built environment, and linguistic analyses