Thermal autonomy of mobile homes under changing urban climate in Phoenix, AZ

Industrial workplaces, especially in vulnerable, hot, and arid developing countries, face major challenges in maintaining indoor comfort conditions due to the escalating problem of global temperature rise. This study investigates passive scenarios of adaptive retrofitting for a case study carpet and rug industrial plant in Cairo, Egypt to achieve indoor comfort conditions and energy efficiency. The research method included a Post Occupancy Evaluation (POE) for the operational phase of individual work units through measurements and simulations to investigate indoor thermal, visual, and acoustic comfort conditions as well as air quality concerns. Thus, the study presents a set of recommendations for building unit(s) and collectively for the entire facility by applying integrated application of building envelope enhancements; optimized opening design, thermal wall insulation and high-albedo (reflective) exterior coatings for wall and roof surfaces. Comparing the modified case to the base case scenario shows significant improvements. Thermal comfort achieved a 16% to 33% reduction in discomfort hours during peak summer, primarily through a 33% increase in air flow velocity and better humidity control. Visual comfort indicated improvements in daylight harvesting, with Daylighting Autonomy increasing by 47% to 64% in core areas, improving light uniformity and reducing glare potential by decreasing peak illuminance by approximately 25%. Thus, the combined envelope and system modifications resulted in a 60 to 80% reduction in monthly Energy Use Intensity (EUI). The effectiveness of the mitigation measures using acoustic insulation was demonstrated in reducing sound pollution transferring outdoors, but the high indoor sound levels require further near-source mitigation or specialized acoustic treatment for complete success. Eventually, the research method helps create a mechanism for measuring and controlling indoor comfort conditions, provide an internal baseline or benchmark to which future development can be compared against, and pinpoint areas of improvement. This can act as a pilot project for green solutions to mitigate the problem of climate change in industrial workplaces and pave the way for further collaboration with the industrial sector.

Thermal comfort in a two-storey malaysian terrace house: Are passive cooling methods sufficient in present and future climates?

Thermal comfort in a mixed-mode building: Are occupants more adaptive?

The COVID-19 pandemic and resulting containment measures have shown that energy consumption in buildings is linked to several factors, such as living habits, occupancy profiles, and heating ventilation and air conditioning (HVAC) systems. This paper addresses the influences of such factors on energy consumption in a residential building, analysing different scenarios (pre-COVID-19, lockdown, post-COVID-19), in terms of discomfort and energy needs, through the new hourly calculation method (UNI EN ISO 52016). Energy and environmental effects were studied in a real case study near Rome by varying occupancy profiles, lighting and appliance schedules, and HVAC systems. Results show that, during the heating period, the lockdown scenario led to the lowest hours of discomfort (−29% on average), but the highest in the cooling period (up to +154%, +28% on average). The same scenario led to reasonable reduction of energy needs for heating (−14%), but also highlighted a significant increase (+60%) for the cooling period. This study underlines how the pandemic has influenced the energy and environmental behaviours in buildings. Moreover, the new hourly calculation method points out the importance of analysing HVAC systems, in terms of hours of discomfort, which could provide results that are more reliable.

Global warming is increasing extreme heat conditions, with existing energy efficiency policies showing trade-offs between mitigation objectives and adaptation to climate change. This research aims to identify the best resilient cooling solutions that should be promoted in the built environment of extremely hot countries to increase their heat resilience capacity. The impact of climate change on climate zones, cooling thermal demand (kWh/m2), and indoor heat discomfort hours (DHh, hours) in buildings is evaluated in different extremely hot dry climates of southern Asia through a parametric analysis for 2020, 2050 and 2080 under the A2 (medium–high) emission scenario. Then, cooling alternatives with higher synergies and trade-offs between energy efficiency (energy consumption) and resiliency to extreme heat (passive survivability) are highlighted. TRNSYS simulation software and ASHRAE criteria were used to characterise climate zones and calculate buildings' cooling needs and discomfort hours. Pakistan, in southern Asia, was selected as a hot reference region characterised by various climatic regions. The simulated scenario shows how Pakistan's extremely hot dry climate surface may increase from 36.9 % to 78.1 % by 2080, increasing annual cooling needs ranging from 20.56 to 66.96 kWh/m2 and indoor discomfort hours ranging from 423 to 1267 h. The results demonstrate how the passive solutions with higher synergies between energy savings and indoor comfort hours are, in decreasing order, ventilative cooling, reflective and ventilated roofs, shading in windows, and roof insulation. They can provide energy savings ranging from 13.1 to 7.1 kWh/m2 while reducing indoor discomfort by 320 to 131 h for extremely hot climates. Moreover, the sufficiency action related to higher thermostat settings, from 24 to 25 °C to 25–26.5 °C, was the most effective strategy to decrease energy demand. Additionally, there are trade-offs between energy-saving and heat resilience with highly insulated alternatives when ventilation is not adequately addressed. Despite increasing energy savings by 14.4 kWh/m2, discomfort hours are increased by 256 hours when air conditioning is unavailable, increasing building overheating by 5.1 %.

This article focuses on adopting effective and affordable bioclimatic building design strategies in Ouagadougou, in the Sudano-Sahelian zone of Burkina Faso. A model representing a standard office building and relevant parameters were input in EnergyPlus, and scenarios were analyzed to evaluate the effect of natural ventilation, window shading, dehumidification with night ventilation, and evaporative cooling with night ventilation on thermal comfort and energy consumption. First, the American Society of Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE) Standard 55 adaptive comfort model was used to compare discomfort hours and interior temperatures between a conventional office design and improved models using passive approaches. The simulations further tested the reduction in energy cooling demand and energy consumption. The results demonstrated that natural ventilation was the most effective passive cooling technique, helping to reduce the annual discomfort hours by 40% and the annual energy consumption by 30%. Combining passive strategies is the best scenario, with a year of office occupancy resulting in just 617 h of discomfort, a 42% reduction in the annual energy cooling demand, and a 43% reduction in the annual energy consumption. The simulations demonstrated the effectiveness of affordable passive design solutions applicable even in existing office buildings and their significance for the sustainable development of fast-urbanizing Sub-Saharan countries.

A comfortable indoor thermal environment is usually controlled through air conditioning, which can greatly improve work efficiency. However, current air conditioning system design may not consider the spatio-temporal distribution of the indoor environment for large-scale buildings, so the air conditioning system needs to be optimized. Few studies have examined such optimization related to different weather conditions outside the building. This study presents a method to formulate an air condition adjustment strategy for each specific zone in a library with large glass curtain walls, based on the diurnal change of thermal environment. We measured the indoor thermal environmental conditions and recorded the thermal comfort perception of room occupants. The Predicted Mean Vote (PMV) and apparent temperature model were adopted to predict the occupants’ thermal comfort, resulting in a suggested comfort range. Based on our results, the comfortable range of PMV and apparent temperature was identified, and this comfortable range could be used as a basis for an example of adjusting the air conditioning system to improve indoor thermal comfort.

Estimating the effect of using cool coatings on energy loads and thermal comfort in residential buildings in various climatic conditions

This paper presents the results of “Upgrade and Save”, a program to upgrade the standard electric furnaces and air-conditioning units in Mobile Homes for energy-efficient heat pumps. This program is implemented in North Carolina, USA and pays about $700 through a rebate provided by the North Carolina State Energy Office to the Mobile Homes' owners. The goal of this project is to subsidize low-income families by lowering their heating cost in the winter as well as improving their homes' indoor thermal comfort. More than 300 mobile homes have participated in this program. Field measurements, meter readings of the actual electrical consumption, and annual building energy simulation were used to measure the dollar saving and the indoor thermal comfort improvement in the mobile homes after the heating system upgrade. This research proved that the dollar saving of using the heat pump for heating in mobile homes ranges from $51 to $128 annually.

Among the factors affecting the energy consumption of buildings, occupancy-related factors are the least understood due to the uncertainty and complexity associated with them. As a result, there is a rise in this area of research focusing on the effect of occupants (e.g., their location, behaviour, etc.) on buildings’ energy consumption. Focusing on office buildings, researchers have suggested several occupancy monitoring techniques in order to minimize the energy usage of existing office buildings. However, a limited number of studies have been conducted to consider proper sensing techniques to distinguish between different occupants in multioccupied offices and to apply local control to adjust the lighting and HVAC systems based on the occupancy information. This research proposes a simulation-based multi-objective optimization of the energy consumption in office buildings considering occupants’ locations and preferences. The objective functions are minimizing the energy consumption and the occupants’ discomfort hours simultaneously by applying local control of the Heating, Cooling, and Air Conditioning (HVAC) system. A case study is presented to demonstrate the feasibility of the proposed method.

A Review on Solar Powered Air Conditioning System

Exploring impact of opaque building envelope components on thermal and energy performance of houses in lower western Himalayans for optimal selection

Performance analysis of different air conditioning systems in apartment buildings under different climates in China

This study presents a new trend of natural and mixed refrigerants as the ideal refrigerants, environmentally friendly and an ideal solution to the problems of ozone-depleting substances and the surrounding environment. HFC refrigerants are presently the main swap for CFC and HCFC refrigerants in air-conditioning systems. During this period of time much consideration has been paid to the conceivable utilize of fluorinated propene isomers for the substitution of HFC liquids, being much of the time high-GWP refrigerants. However, the available hydrofluoroolefins (HFOs) can't cover all the refrigeration and air-conditioning systems when utilized as pure fluids this because the properties are not reasonable for all working conditions. In this paper analyses the behavior of different new trends in the natural and mixed refrigerants. In chillers, R1234ze(E) can considerably reduce CO2 final emissions, as well as, R1234ze(E) is a good option in air conditioning and refrigeration systems.

Sustainable High-rises