Maintaining Indoor Thermal Comfort Research Articles

Experimental analysis of building envelope integrating phase change material and cool paint under a real environment in autumn

The application of phase change material (PCM) and cool paint (CP) to building envelope is one of the effective solutions to improve thermal comfort of passive buildings. Therefore, the thermal performance of buildings in Hefei, China in autumn is compared and analyzed by integrating PCM and CP into the building envelope. According to the comprehensive analysis of indoor thermal environment and the ability to maintain indoor thermal comfort, it is concluded that the combined application of PCM and CP is better than the application of PCM or CP alone. And the combination of PCM and CP laid on the south wall and roof respectively is the best. It is more suitable for commercial buildings, which can prolong indoor air temperature (Ti) in the thermal comfort zone for more than 10 hours during the day. The combination of PCM and CP laid on the roof can prolong Ti in the thermal comfort zone for more than 8.05 hours, which is more suitable for residential buildings. The purpose is to explore the best combination mode of residential and commercial buildings according to the characteristics of temperature change and building types (according to people's main use time) in the real environment.

Compressor speed control for optimizing energy matching of PV-driven AC systems during the cooling season

Photovoltaic-driven air conditioning (PVAC) systems innovatively utilize PV power for building cooling, reducing PV power fluctuation impact on the utility grid. This study introduced a novel PVAC system that optimizes the energy matching between PV generation and air conditioning electricity demand through directly controlling of the compressor speed in accordance with the real-time PV power generation. A PID control method was employed to regulate the compressor speed of PVAC, and three control strategies were proposed and successfully implemented during the experiments. The system's efficiency was evaluated using metrics such as the self-consumption rate (SCR), self-sufficiency rate (SSR), real-time zero energy proportion (RZEP), and the mean absolute error (MAE) of indoor temperature. The results of this study confirm that the proposed control method significantly enhances the power matching between the PV power generation and the air conditioning electricity demand. Implementing the recommended strategy, SCR increased from 0.53 to 0.625 and SSR from 0.716 to 0.808, all while maintaining indoor thermal comfort. Moreover, the proposed approach mitigates the impact of distributed PV generation on the utility grid and potentially diminishes energy storage needs, which can contribute to a lower system investment requirements and operating costs.

Enhancing indoor thermal comfort and sustainability: A solar-driven desiccant cooling and adsorption chiller system with environmental impact assessment

Addressing indoor thermal comfort in buildings located in hot and humid climates is a persistent challenge, demanding innovative cooling solutions that are both efficient and environmentally responsible. This paper introduces a new integration of a Phase Change Material (PCM)-based solar desiccant cooling system with an adsorption chiller, a setup designed to enhance indoor thermal comfort conditions while utilizing renewable energy sources. This research simultaneously leverages the heating and cooling capacities of the adsorption chiller, leading to an efficient system performance. The TRNSYS software is used to evaluate the system's behavior in a typical house with moderate cooling demand and characterized by high relative humidity. Two types of solar collectors, the evacuated tube and Wavy Direct Absorption Solar Collectors (WDASC), are evaluated to supply the required thermal energy, providing a comprehensive assessment of the system’s efficiency under different configurations. Additionally, the study conducts a comprehensive Life Cycle Assessment (LCA) to quantify the Global Warming Potential (GWP) of the systems. The results confirm the proposed system's capability to maintain indoor thermal comfort within acceptable Predicted Mean Vote (PMV) and Predicted Percentage of Dissatisfied (PPD) ranges. The evacuated tube collector showed marginally better performance (average PMV: 0.018, average PPD: 6.7 %) compared to the WDASC (average PMV: 0.075, average PPD: 7.3 %). Additionally, the evacuated tube collector demonstrates superior energy (75.68 %) and exergy (10.82 %) efficiencies compared to the WDASC. The system utilizing the evacuated tube collector surpasses the WDASC configuration, achieving a higher Coefficient of Performance (COP) of 0.47 compared to 0.41, and emitting lower GWP values of 0.0194 kg-CO2 per kWh of cooling capacity compared to 0.0201 kg-CO2. An analysis of Embodied Energy reveals that the adsorption chiller is the most significant contributor to lifecycle energy consumption, with a quicker Energy Payback Time (EPBT) for the evacuated tube system (2.75 years) compared to the WDASC system (3.94 years). This research thus contributes a highly efficient, sustainable, and environmentally friendly solution to the challenge of cooling in buildings, setting a new standard for future green building practices.

Spatial distribution and transient responses of the thermal environment in an office space equipped with a standing-type air conditioner

Air conditioner (AC) systems are important for maintaining indoor thermal comfort, but discrepancies can exist between setpoints and the actual room temperature. In the present study conducted in a typical Korean office during summer, we identified differences of up to 2.77 °C between the AC setpoint and the average room temperature. This variation may have originated from the oscillatory cooling pattern, leading to moments of discomfort even though the overall thermal balance was maintained. While consistent initial cooling rates were observed for various setpoints, oscillations at 20 °C lowered the efficiency of the AC system. A bi-exponential model applied to the cooling pattern confirmed a two-phase cooling process. Interestingly, the coefficient of performance was highest at the lowest temperature setpoint, even though this led to greater energy consumption and possible overcooling. The weather strongly affected AC performance, with rainy conditions requiring less power than sunny conditions at the same setpoint. Furthermore, our experiment comparing the predicted mean vote (PMV) with actual human comfort revealed that the PMV often recommends a cooler ambient temperature than what occupants actually prefer.

Optimization control strategy for mixed-mode buildings based on thermal comfort model: A case study of office buildings

Mixed-mode (MM) buildings reduce air conditioning (AC) energy consumption while maintaining indoor thermal comfort through the appropriate use of natural ventilation (NV). The objective of this investigation was to propose a method to determine the best NV operation range suitable for MM buildings and further to propose a change-over control strategy. First, the usual natural ventilation operating range (NV-range) was obtained based on the upper and lower comfort temperature limits of the adaptive comfort model. The usual NV-range was extended by adding threshold conditions, and then, it was divided into nine natural ventilation operation subranges (NVOSs). Second, the comfort and energy performance of each NVOS were analyzed through a co-simulation for an MM office building in Xi'an, China, as an example to obtain the optimal NV-range for the local climate. The results showed that the proposed optimal NV-range reduced the number of discomfort hours by 248.33 h while increasing the energy savings by 13.29% compared to those of the commonly used NV-ranges. Finally, the control scheme with the adaptive comfort model changed to the PMV model (ACM-PMV-CS) with the addition of a 1.5-h transition period was proposed in order to solve the problem of using the steady-state PMV model directly in the AC mode under the frequent switching conditions between the NV and AC modes. The results showed that ACM-PMV-1.5 h transition period resulted in a reduction in the number of discomfort hours (248.33 h) and a 35.46% increase in the energy savings compared to those of ACM-PMV-CS without a transition period.

Strategies for maintaining indoor temperature in rural residences in highland pastoral areas

Previous studies on improving indoor thermal environments focus on plain areas. However, the scattered rural residences in highland pastoral areas have special climatic conditions and living habits. This article presents an approach to utilize the abundant renewable energy in the local area to create an indoor thermal environment that residents need. A rural village in Qinghai province of China was taken as the target; we used field investigation and questionnaire survey to explore typical layout. Combined with local building codes, two envelope and two heating systems were proposed to achieve indoor thermal comfort. We also introduce building simulation models and field tests to discover four combinations’ energy-saving effects in maintaining indoor thermal comfort. The average energy-saving rate in the heating season of the four schemes is 89.31%, and the mean temperature is 16.64 °C. The results suggest the heating system has a more significant influence on energy consumption than the enclosure structure, which needs attention under the same budget situation. The solar air heating system has better indoor temperature maintenance effects than the carbon fiber floor heating system. Regarding construction, the prefabricated integrated enclosure structures improve thermal insulation performance significantly.

Simulation-based assessment of the climate change impact on future thermal energy load and indoor comfort of a light-weight ecological building across the six climates of Morocco

The potential effects of global climate change on buildings are a growing concern worldwide, as rising temperatures can significantly impact their energy performance and indoor thermal comfort conditions. This article examines the impact of global warming across six different climate zones of Morocco by comparing under 2050 RCP8.5 scenario the current and future thermal energy requirements and indoor comfort levels of a light-weight ecologically-designed detached residential house. The reference case study building is in a semi-arid climate of Morocco and empirically validated following the ASHRAE guideline 14, with CV(RMSE) less than 3.2 and NMBE less than 1.4 for the two 38-day monitored thermal zones.The study includes aframework to evaluate the thermal energy needs for maintaining indoor thermal comfort and the overheating intensity triggered by climate change and varying due to spatial scale. Overall, the findings show that Morocco will suffer with differing magnitudes from the temperature increase linked to global warming, which will result in an upsurge in the thermal needs for cooling, particularly in the southern regions of Morocco, and a general reduction in the heating thermal energy needs across the different climates of Morocco, with an annual thermal energy demand change ranging from −2.7% to 17%, depending on the investigated city. This wide variation in thermal energy demand underlines the need to assess the effects of the warming climate in the local context. Besides, under conditions of Air Conditioning (AC) failure, the Indoor Overheating Hours (IOH) increase up to 27% between the current climate conditions and the 2050 climate conditions while indoor temperature changes exceed 1.5 °C during the hottest days of the summer.Strategically, the research study intends to support global efforts to build resilient societies by bringing awareness to how susceptible indoor occupants are to projected warming temperatures. The study also lays the groundwork for prioritizing and assessing adaptation solutions to protect people's health, comfort, and productivity within buildings despite climate change in the most sustainable manner.

The design of solar power thermoelectric radiant panel as cooling system in small buildings under tropical climate

The usage of an air–conditioning (AC) system in any building is necessary to maintain its indoor thermal comfort and health. However, this system consumes a lot of energy, while the usage of refrigerant causes irreversible damage to the ozone layer. To solve this problem, a solar thermoelectric radiant panel (PV-TERP) system has a high potential in replacing conventional AC system because it requires no refrigerant and easier to be controlled due to the absence of moving and mechanical parts such as water pumps, compressors, including auxiliary and hydronic pipes. Meanwhile, the usage of solar energy in the PV-TERP system can also help reduce fossil energy consumption and carbon emissions. The main objective of this work is to design a new PV-TERP system for replacing conventional AC systems in buildings located in tropical climate countries, like Malaysia. It is found that the designed PV-TERP system can provide up to 4.84 kW of cooling power, which is about 0.6% higher than the cooling load of targeted rooms. Here, the targeted rooms operate under indoor parameters within the acceptable range of ASHRAE standard-55. The obtained results clearly show that the new design is applicable to be used as a cooling system for the targeted building. In the future, it is then essential to understand the thermal properties and mechanism of the design via simulation process, followed by experimental validation to support the design feasibility. In conclusion, this new design of PV-TERP will lead the path toward expanding renewable energy applications for cooling purposes in sustaining and preserving the environment. HIGHLIGHTS Alternative cooling system in replacing air-conditioning (AC) system for maintaining indoor thermal comfort without harming the environment. Designation of the PV-TERP system as a cooling system for building in a tropical country (Malaysia) under indoor parameters within the acceptable range of ASHRAE Standard-55. The designed PV-TERP is refrigerant-free and operates using renewable energy, which can sustain and preserve the environment for a better future. GRAPHICAL ABSTRACT

Numerical Simulation of a Efficient Solar-Powered Ventilation System

The objective of this study is to conduct a numerical analysis of a small-scale solar ventilation-air conditioning system operating under the meteorological conditions of Bisha, Saudi Arabia. The primary objective of the proposed system is to provide sustainable and comfortable thermal conditions. To achieve this objective, the system recovers the heat wasted by the solar ventilation process and reuses it to power the desiccant dehumidification process. The solar chimney features a lateral (vertical) wall design, and a comparative performance investigation of two solar chimney designs (conventional vs original) is conducted. Mathematical models of the ventilated room and solar chimney are developed, and numerical simulations are carried out to evaluate the performance of each solar chimney design. The study aims to assess the ability of each design to maintain indoor thermal comfort through the analysis of air distribution temperature and air streamlines. The results of the performance comparison revealed that the proposed solar chimney design outperformed the conventional design in terms of thermal and ventilation performance. The proposed solar chimney design, with its lateral (vertical) wall, was also found to be more effective in maintaining indoor thermal comfort than the conventional design. The simulations showed that the proposed design produced a more uniform air distribution temperature within the ventilated room, resulting in improved comfort levels. Additionally, the proposed design was found to have a more efficient airflow pattern, with fewer areas of stagnant airflow. These results suggest that the proposed solar ventilation-air conditioning system has the potential to provide sustainable and comfortable thermal conditions in small-scale buildings.

Impact of outdoor particulate matter 2.5 pollution on natural ventilation energy saving potential in office buildings in China

Natural ventilation improves building energy performance and indoor air quality, but its potential is hindered by outdoor pollution. This paper aims to evaluate the impact of outdoor Particulate Matter 2.5 (PM2.5) pollution on natural ventilation energy saving potential in office buildings in China. Firstly, a typical office building in five representative cities across all climatic regions was designed. Secondly, related weather data were obtained and preprocessed. Thirdly, a computer model was developed under the EnergyPlus environment with smart window ventilation control, space temperature reset using adaptive thermal comfort model, and a validated pollution transportation model that calculates the indoor PM2.5 concentration. The computer model was applied to three air-conditioning systems, i.e., constant air volume (CAV), variable air volume (VAV), and variable refrigerant flow (VRF) with three evaluation indices. The results show that the natural ventilation hours rate with/without considering the outdoor PM2.5 concentration level were 15%–55% and 28%–67%, respectively. Energy savings varied across regions, with mild regions having the highest potential and cold regions having the least. CAV demonstrates the highest energy savings, followed by VAV and VRF, except in Guangzhou where VAV performs the worst. This study contributes to understanding the impact of outdoor pollution on natural ventilation potential and provides practical insights for energy-saving strategies in office buildings. Its originality lies in the evaluation methodology, comprehensive approach, sophisticated computer model, comparative analysis of air-conditioning systems, and practical implications for energy-savings. The research outcomes can guide building facility engineers in implementing ventilation control strategies while maintaining indoor thermal comfort.

Energy flexibility analysis and model predictive control performances of space heating in Japanese zero energy house

With improved building energy-saving standards and development of on-site renewable energy, efficient energy management strategies and enhanced energy flexibility can play crucial role in decarbonizing the building energy system. In this work, the potential of the thermal energy flexibility of space heating in Japanese zero energy house is analyzed based on real measurements and a reduced-order simulation model. The impacts of relevant parameters on energy flexibility were provided under different conditions. The model predictive control (MPC) framework was then developed for the house space heating system, and it formulated the optimization as a mixed-integer linear programming problem for minimizing energy consumption while maintaining indoor thermal comfort. The results of conducted case studies verified the feasibility and effectiveness of the proposed optimization approach in achieving flexible control of space heating systems. The control performances of the proposed MPC strategies were associated with different objectives, comparative analysis demonstrates that the designed control approach can effectively achieve an optimal trade-off between on-site photovoltaic consumption and thermal comfort by allowing acceptable indoor temperature violations. The energy flexibility provided by the space heating system could achieve an approximately 20% improvement in photovoltaic self-consumption ratio compared to real measurement over the testing period.

Cost-Effective Heating Control Approaches by Demand Response and Peak Demand Limiting in an Educational Office Building with District Heating

This study examined three different approaches to reduce the heating cost while maintaining indoor thermal comfort at acceptable levels in an educational office building, including decentralized (DDRC) and centralized demand response control (CDRR) and limiting peak demand. The results showed that although all these approaches did not affect the indoor air temperature significantly, the DDRC method could adjust the heating set point to between 20–24.5 °C. The DDRC approach reached heating cost savings of up to 5% while controlling space heating temperature without sacrificing the thermal comfort. The CDRC of space heating had limited potential in heating cost savings (1.5%), while the indoor air temperature was in the acceptable range. Both the DDRC and CDRC alternatives can keep the thermal comfort at good levels during the occupied time. Depending on the district heating provider, applying peak demand limiting of 35% can not only achieve 13.6% maximum total annual district heating cost saving but also maintain the thermal comfort level, while applying that of 43% can further save 16.9% of the cost, but with sacrificing a little thermal comfort. This study shows that demand response on heating energy only benefited from the decentralized control alternative, and the district heating-based peak demand limiting has significant potential for saving heating costs.

Energy assessment of a residential building renovated with a novel prefabricated envelope integrating HVAC components

Off-site prefabrication systems continuously gain attention in the building industry as they combine fast construction with fewer and more sustainable resources as well as minimize disturbance for occupants. In this direction, adaptable off-site prefabricated envelope components with embodied HVAC systems have been developed as an effective renovation solution. They can minimise thermal losses through the envelope while at the same time integrated HVAC systems efficiently maintain indoor thermal comfort conditions. In this study, a “Plug-and-Play” prefabricated envelope component incorporating HVAC systems is examined as a solution for the deep renovation of a typical single-family residence in Berlin, aiming to reach NZEB state. This versatile modular system, called SmartWall, can be installed either to the exterior or the interior side of the external wall, incorporating timber-based frame, boards and insulation, high-performance windows and a slim-type fan coil. The evaluation of this prefabricated system is investigated with respect to its energy performance both at component and building level, as well as its calculated embodied energy. The results indicate a reduction of 89% total primary energy highlighting that NZEB state can be ensured if the SmartWall application is combined with sufficient photovoltaic modules. The climate change potential contribution of such retrofit indicates a significant amount of embodied energy, which is nevertheless counterbalanced by the operational energy savings within the first few years after the implementation.

Energy consumption optimization of building air conditioning system via combining the parallel temporal convolutional neural network and adaptive opposition-learning chimp algorithm

Heating, ventilation, and air-conditioning systems provide a comfortable indoor thermal environment, but high energy consumption is often necessary to achieve an adequate level of indoor thermal comfort. However, it is challenging to design an energy-efficient thermal comfort control strategy, mainly because the internal thermal environment is influenced by complicated factors and difficult to model accurately. To solve this problem, a control strategy incorporating the parallel temporal convolutional neural network (PTCN) and the improved chimp optimization algorithm (ICHOA) is proposed for thermal comfort control of buildings. Thermal comfort control is transformed into a cost-minimization problem by establishing an objective function for both the future thermal comfort of the occupants and energy consumption and optimizing multiple air-conditioning temperature set points for the coming day. First, to ensure the prediction performance, a PTCN model was developed to predict the energy consumption and thermal comfort under different factors. An opposition-learning-based adaptive chimp algorithm was then used to solve the objective function to output the optimal set temperature. Finally, the superiority of the PTCN-ICHOA optimization strategy was verified using an office building in Jinan as an example. In winter and summer experiments, the proposed PTCN model achieved the lowest prediction errors among the models compared in terms of energy and temperature prediction. Furthermore, the PTCN-ICHOA optimization model exhibited faster convergence than the other models for both experiments. Through the proposed optimization strategy, energy consumption savings of approximately 6.3%–8.1% can be achieved while maintaining indoor thermal comfort.

Thermal performance optimization of a semi-nested building coupled with an earth-to-air heat exchanger using iterative Taguchi method

In this paper, a semi-nested building coupled with an earth-to-air heat exchanger is investigated to maintain indoor thermal comfort and reduce building energy consumption. Firstly, the computer models on the semi-nested building coupled with earth-to-air heat exchanger were developed under the TRNSYS environment. Secondly, the simulation results from the computer models were validated with experimental data from open literature. Finally, iterative Targuchi method was employed to find the optimal design values for the envelope properties and earth-to-air heat exchanger configurations. The optimal values of the design parameters were found to be A1 (window-to-wall ratio of 10%), B3 (triple-layer Low-E glazing window), C3(insulation thickness of 200 mm for external wall),D3 (concrete slab thickness of 250 mm for external wall), E3(absorption of solar radiation for external walls of 0.75), F3(absorption of solar radiation for the roof of 0.75),G5 (earth tube inner diameter and air gap of 300 mm and 400 mm, respectively), H2 (earth tube length of 50 m), and I3 (duct air velocity of 1.5 m/s).

Influence of building envelope characteristics on the effectiveness of PMV-based controls for schools located in Saudi Arabia

This paper summarizes the results of a comprehensive analysis to investigate the performance of both thermal comfort-based and temperature-based controls for schools in harsh hot climates of Saudi Arabia. The analysis considers the impact of building envelope characteristics including thermal insulation level of exterior walls and air leakage rate on the ability of both control options to maintain indoor thermal comfort while minimizing cooling energy consumption. The analysis utilizes a calibrated energy model for an existing Saudi school with monitored energy consumption data. The analysis results indicated that the thermal comfort-based control is able to maintain the predicted percentage of dissatisfied (PPD) value at 5% throughout the year for any combination of the exterior wall’s R-value and air infiltration rate unlike the case of the temperature-based controls that do not maintain acceptable indoor thermal comfort conditions. However, the thermal comfort-based controls consume more cooling energy than the temperature-based controls. The analysis also revealed that the difference between the annual cooling energy of the PMV-based control and the temperature-based controls increases almost linearly with the cooling degree days of the site where the school is located. The analysis results indicate that acceptable indoor thermal comfort levels can be achieved using temperature-based controls when optimal temperature set points are used.

Study of a thermally enhanced mortar incorporating phase change materials for overheating reduction in buildings

The use of thermal energy storage systems incorporating Phase Change Materials (PCM) as passive thermal regulators, in innovative buildings’ applications is an increasing trend and promising strategy for maintaining indoor thermal comfort while promoting buildings’ energy efficiency in a sustainable way. Incorporating PCM into mortars enhances their thermal properties but modifies physical and mechanical characteristics. This paper presents an experimental research on the microstructural, mechanical, and thermal properties of innovative cementitious mortars incorporating two different microencapsulated PCMs, targeted for low thermal mass constructions located in warm climates.The characterization was developed in three steps: microstructural evaluation using scanning electron microscopy; physical and mechanical characterization by workability, density as well as compressive and flexural strength tests; and thermal characterization through enthalpy-temperature curves, determined with differential scanning calorimetry, and the assessment of real case application to evaluate the impact over the thermal behaviour of a lightweight constructive solution with the developed mortars as inner finishing layer using the hot box heat flux metre method at steady-state conditions. Results revealed an expressive decrease in flexural and compressive strength; significant loss of latent heat capacity and variations of onset and peak melting temperatures were observed; good correlation between thermal conductivity and mean specimen temperatures were attained for the lightweight opaque building solution tested with the two different PCMs, for temperatures below and above the phase change transition zone.

Experimental evaluation of the performance for switchable insulated shading systems

This paper evaluates through experimental testing a prototype of switchable insulated shading (SIS) systems suitable for windows to optimize solar heat gains in order to maintain indoor thermal comfort. Specifically, the paper describes a laboratory testing procedure and measurement results for SHGC values specific to various SIS designs and operation settings using a box calorimeter set-up. The SIS prototype can modulate continuously its optical and thermal properties including U-value and SHGC using rotating insulation layers controlled through an actuator to a specific slate angle setting. The results of the experimental testing confirm that SHGC value for the SIS prototype is correlated to the slate angle of the insulated layers. This correlation remains applicable for any SIS insulation thickness. The measured data are used to assess the potential energy efficiency benefits from SIS when applied to windows for US homes. In particular, a prototypical housing unit located in three US cities is considered to evaluate the energy efficiency potential for switchable opaque insulated shading systems. The results indicate that SIS systems can achieve up to 8.3%, 11.3%, and 11.4% in annual HVAC energy consumption compared to no-shading cases for dwellings located in Golden, CO (representing a cold climate), Phoenix, AZ (representing a hot climate), and San Francisco, CA (representing a mild climate), respectively.

Cooling seasonal performance of inverter air conditioner using model prediction control for demand response

The supply-demand imbalance of electricity increases the operating burden on smart grids, decreases the average efficiency of power generation equipment, and threatens the safe operation of power grids. Residential air conditioning is a flexible load and a major consumer of electricity. Therefore, demand response control can be applied to air conditioners (ACs) to shift their peak energy consumption and save energy. Model predictive control (MPC) is an effective demand response control method. In this study, we analyze the cooling seasonal performance of an inverter AC with MPC. A time-varying MPC was designed and evaluated using a simulation testbed that was constructed using MATLAB. Subsequently, the energy, cost, and temperature control performances of the MPC were analyzed in detail from electricity pricing model, weather conditions and fluctuation of real-time price. The results show that compared to the proportional–integral–derivative (PID) control method, MPC can shift the peak-hour energy consumption by 6.34%–21.60% and reduce the total electricity costs by 13.44%–27.43%, while maintaining indoor thermal comfort during the whole cooling season, and Demand response with MPC control is very suited to hot weather conditions with highly fluctuating RTP. By applying MPC hybrid demand response under real-time price, there are better performances on peak shifting and cost saving.

The Significance of the Adaptive Thermal Comfort Practice over the Structure Retrofits to Sustain Indoor Thermal Comfort

Any building’s design should sustain thermal comfort for occupants and promote less energy usage during its lifetime using accurate building retrofits to convert existing buildings into low-energy buildings so that the heating and cooling loads can be minimized. Regarding the methodology adopted in this research, an energy model of an educational building located at the German Jordanian University in Jordan was constructed utilizing DesignBuilder computer software. In addition, it was calibrated utilizing real energy consumption data for a 12-month simulation of energy performance. Subsequently, a computerized evaluation of the roles of building envelope retrofits or the adaptive thermal comfort limits in the reduction of the overall building energy consumption was analyzed. The results of the study show that the current building’s external wall insulation, roof insulation, glazing, windows, and external shading devices are relatively energy-efficient but with high cost, resulting in significant financial losses, even though they achieved noticeable energy savings. For instance, equipping the building’s ventilation system with an economizer culminated in the highest financial profit, contributing to an annual energy savings of 155 MWh. On the other hand, in an occupant-centered approach, applying the adaptive thermal comfort model in wider ranges by adding 1 °C, 2 °C, and 3 °C to the existing operating temperatures would save a significant amount of energy with the least cost (while maintaining indoor thermal comfort), taking over any retrofit option. Using different adaptive thermal comfort scenarios (1 °C, 2 °C, and 3 °C) led to significant savings of around 5%, 12%, and 21%, respectively. However, using different retrofits techniques proved to be costly, with minimum energy savings compared to the adaptive approach.