This paper considers pre-retrofit and post-retrofit lighting energy end-use of two sub-metered office spaces. Building lighting retrofits are typically installed to reduce energy consumption and operational costs of buildings. This traditionally includes replacing lights and introducing Building Management System (BMS). Through this process, an occupant’s ability to override new computerized controls could be compromised, which can dramatically affect the overall success of the project. Therefore, the analysis focuses on the effectiveness of the lighting retrofit, influence of the BMS upgrade, occupant behavior, and the lessons learned. The analysis comprises three different phases including one pre-retrofit and two post-retrofit phases. Each of the retrofit phases lasted approximately one year, leading to the monitoring of three years of sub-metered lighting energy end-use. The results showed that when the occupants had access to the lighting switches while BMS managed the operational lighting schedule, the office area with the responsible occupant saved 23.2% compared to the pre-retrofit phase. For the second lighting retrofit phase when the occupants did not have access to the light switches, the lighting schedule operated for more than two hours after the typical work day and the occupant was not able to turn off the lights upon departure. It should be noted that there are limited numbers of studies that consider three years sub-metered lighting retrofit data with the presented granularities in this study. Similar lighting retrofit projects could benefit from the findings of this study. Finally, the results of this sub-metered lighting data could address uncertainty in the selection of lighting power density and associated schedules of building energy simulations.

The convective heat transfer is an important component in the estimation of thermal balance of energy for arrays of buildings immersed in a turbulent boundary layer. This study proposes a novel cost-effective validation approach using targeted field measurements and numerical simulations as an alternative to the wind-tunnel and full-scale field measurement approaches that typically require significant human resources and instrumentation to develop convective heat transfer coefficient (CHTC) for buildings located in the urban environment. This study first introduces new CHTC correlations for regular arrays of cubic buildings. A field measurement is then conducted in an actual urban thermal environment characterized by the plan area density λ_p = 0.25. Afterwards, this urban thermal environment is numerically simulated using CHTC values for the specified λ_p and appropriate thermal boundary conditions. The results of the numerical simulations are compared with the measured air temperatures to indirectly validate the CHTCs for external surfaces of buildings. The results show that the difference between the simulated and measured air temperatures is small and typically within 5%. Furthermore, this study created a calibrated building energy simulation model to deploy newly developed CHTCs for building heating energy consumption calculations. Specifically, the energy simulations used both newly developed and commonly used CHTCs to analyze the influence of CHTCs on the heating energy simulation results. A comparison between the simulated heating and actual heating energy consumption shows that the developed CHTCs have a positive influence on the accuracy of the energy simulation results.