Evaluation of the energy performance and thermal comfort of an air conditioner with temperature and humidity controls in a cooling season

Energy, environment and economics are considered as very vital parameters for the evaluation of an air conditioning system and associated indoor environment. The cooling performance of an air conditioner has an effect on the thermal comfort of occupants in the room. Transcritical CO 2 air conditioner (System B) with a control for gas cooler pressure has better energy performance than a transcritical CO 2 air conditioner (System A) without any control on the gas cooler pressure. An experimental technique is used for generating performance equations to define transcritical CO 2 air conditioners in the EnergyPlus program. EnergyPlus simulates combined model of a transcritical CO 2 air conditioner and room for known yearly weather data for an effect on thermal comfort in the room. Thermal comfort in the room is evaluated using the Fanger thermal comfort model and the Pierce two node model. The better energy performance of System B results in improved indoor room environment of the room. The total cooling of System B is 15.78–20.2% higher than that of System A. The Fanger thermal comfort model shows that 95% to 133% people are more dissatisfied with an indoor thermal environment during the morning and 85% to 127% people during the afternoon for a room coupled with System A vis-à-vis room with System B.

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Experimental Data and Simulations of Performance and Thermal Comfort in a Typical Mediterranean House

Energies ◽

10.3390/en14113311 ◽

2021 ◽

Vol 14 (11) ◽

pp. 3311

Author(s):

Víctor Pérez-Andreu ◽

Carolina Aparicio-Fernández ◽

José-Luis Vivancos ◽

Javier Cárcel-Carrasco

Keyword(s):

Energy Efficiency ◽

Thermal Comfort ◽

Energy Demand ◽

Natural Ventilation ◽

Thermal Characterization ◽

Energy Performance ◽

Building Stock ◽

Energy Demands ◽

Dwelling House ◽

Account Standard

The number of buildings renovated following the introduction of European energy-efficiency policy represents a small number of buildings in Spain. So, the main Spanish building stock needs an urgent energy renovation. Using passive strategies is essential, and thermal characterization and predictive tests of the energy-efficiency improvements achieving acceptable levels of comfort for their users are urgently necessary. This study analyzes the energy performance and thermal comfort of the users in a typical Mediterranean dwelling house. A transient simulation has been used to acquire the scope of Spanish standards for its energy rehabilitation, taking into account standard comfort conditions. The work is based on thermal monitoring of the building and a numerical validated model developed in TRNSYS. Energy demands for different models have been calculated considering different passive constructive measures combined with real wind site conditions and the behavior of users related to natural ventilation. This methodology has given us the necessary information to decide the best solution in relation to energy demand and facility of implementation. The thermal comfort for different models is not directly related to energy demand and has allowed checking when and where the measures need to be done.

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Thermal Dynamic Behavior in Bi-Zone Habitable Cell with and without Phase Change Materials

Proceedings ◽

10.3390/proceedings2020063041 ◽

2020 ◽

Vol 63 (1) ◽

pp. 41

Author(s):

Hanae El Fakiri ◽

Lahoucine Ouhsaine ◽

Abdelmajid El Bouardi

Keyword(s):

Thermal Behavior ◽

Thermal Comfort ◽

Phase Change ◽

Dynamic Behavior ◽

Phase Change Materials ◽

Energy Performance ◽

High Energy ◽

Water Heater ◽

Simplified Modeling

The thermal dynamic behavior of buildings represents an important aspect of the energy efficiency and thermal comfort of the indoor environment. For this, phase change material (PCM) wallboards integrated into building envelopes play an important role in stabilizing the temperature of the human comfort condition. This article provides an assessment of the thermal behavior of a “bi-zone” building cell, which was built based on high-energy performance (HEP) standards and heated by a solar water heater system through a hydronic circuit. The current study is based on studying the dynamic thermal behavior, with and without implantation of PCMs on envelope structure, using a simplified modeling approach. The evolution of the average air temperature was first evaluated as a major indicator of thermal comfort. Then, an evaluation of the thermal behavior’s dynamic profile was carried out in this study, which allowed for the determination of the PCM rate anticipation in the thermal comfort of the building cell.

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Investigation of the cooling performance and thermal comfort for 4-way cassette air conditioner with swinging motion of vanes

Journal of Mechanical Science and Technology ◽

10.1007/s12206-021-0338-1 ◽

2021 ◽

Vol 35 (4) ◽

pp. 1757-1770

Author(s):

Ho Yeon Choi ◽

Jae Hyun Oh ◽

Man Su Park ◽

Sai Kee Oh ◽

Yong Gap Park ◽

...

Keyword(s):

Thermal Comfort ◽

Air Conditioner ◽

Cooling Performance

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Occupant behaviour and thermal comfort in buildings: Monitoring the end user

E3S Web of Conferences ◽

10.1051/e3sconf/201911104056 ◽

2019 ◽

Vol 111 ◽

pp. 04056

Author(s):

Loes Visser ◽

Boris Kingma ◽

Eric Willems ◽

Wendy Broers ◽

Marcel Loomans ◽

...

Keyword(s):

Thermal Comfort ◽

Energy Performance ◽

The Body ◽

Activity Level ◽

Biophysical Model ◽

Zone Model ◽

Occupant Behaviour ◽

Ambient Conditions ◽

Skin Temperatures ◽

Thermoregulatory Behaviour

Studies indicate that the energy performance gap between real and calculated energy use can be explained for 80% by occupant behaviour. This human factor may be composed of routine and thermoregulatory behaviour. When occupants do not feel comfortable due to high or low operative temperatures and resulting high or low skin temperatures, they are likely to exhibit thermoregulatory behaviour. The aim of this study is to monitor and understand this thermoregulatory behaviour of the occupant. This is a detailed study of two females living in a rowhouse in the city of Heerlen (Netherlands). During a monitoring period of three weeks over a time span of three months the following parameters were monitored: activity level, clothing, micro climate, skin temperatures and thermal comfort and sensation. Their micro climate was measured at five positions on the body to assess exposed near body conditions and skin temperature. Every two hours they filled in a questionnaire regarding their thermal comfort and sensation level (7-point scale), clothing, activities and thermoregulatory behaviour. The most comfortable (optimal) temperature was calculated for each person by adopting a biophysical model, a thermoneutral zone model. This study shows unique indivual comfort patterns in relation to ambient conditions. An example is given how this information can be used to calculate the buildings energy comsumption.

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Supply airflow control algorithm of a floor-standing room air-conditioner to achieve thermal comfort for residential housing in summer

Building and Environment ◽

10.1016/j.buildenv.2012.08.022 ◽

2013 ◽

Vol 59 ◽

pp. 227-238 ◽

Cited By ~ 7

Author(s):

Jeong-Hoon Yang ◽

Taeyeon Kim ◽

Chang Heon Cheong

Keyword(s):

Thermal Comfort ◽

Control Algorithm ◽

Air Conditioner ◽

Residential Housing

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Efficiency Enhancement on Thermal Comfort Assessment of Indoor Space with Air-Conditioner Using Computational Analysis

Mathematical Problems in Engineering ◽

10.1155/2014/739619 ◽

2014 ◽

Vol 2014 ◽

pp. 1-7

Author(s):

Yu-Tuan Chou ◽

Shao-Yi Hsia ◽

Bi-Wen Lee

Keyword(s):

Taguchi Method ◽

Thermal Comfort ◽

Flow Simulation ◽

Successful Implementation ◽

Outlet Temperature ◽

Air Conditioner ◽

Indoor Space ◽

Factorial Method ◽

Operation Conditions ◽

Full Factorial

Thermal comfort providing is one of the biggest uses of energy in building. For giving better human comfort, the suitable operation conditions of air-conditioner are the most important. The quick and right approach is necessary. In this paper, a small office is studied to improve office staff staying for a long period of time and achieve the thermal comfort environment for reducing energy consumption. Commercial software, Solidworks, is utilized for modeling the facilities and the Flow Simulation module for analyzing the air properties of the indoor space. Four types of air-conditioner operation are applied to set the simulated conditions, including exterior temperature, outlet temperature and wind speed of air-conditioner, and location of air-conditioner. Predicted mean vote (PMV) and predicted percent dissatisfied (PPD) at specific office areas are further acquired through dynamic anthropometry. For seeking the optimal control factors, both of the full factorial method and Taguchi method are utilized to obtain the PMV of specified location. The analyzed result shows the evaluation speed of indoor thermal comfort by Taguchi method is faster than the full-factorial method. It is concluded that software simulation with Taguchi method shows the successful implementation and higher efficiency for thermal comfort assessment.

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