scholarly journals Estimating Smart Wi-Fi Thermostat-Enabled Thermal Comfort Control Savings for Any Residence

2021 ◽  
Vol 3 (4) ◽  
pp. 743-760
Author(s):  
Abdulelah D. Alhamayani ◽  
Qiancheng Sun ◽  
Kevin P. Hallinan
Keyword(s):  
Thermal Comfort ◽  
Energy Savings ◽  
Short Term Memory ◽  
Control Strategies ◽  
Residential Buildings ◽  
Real Data ◽  
Accurate Estimation ◽  
Indoor Temperature ◽  
Vote Model ◽  
Neural Network Algorithm

Nowadays, most indoor cooling control strategies are based solely on the dry-bulb temperature, which is not close to a guarantee of thermal comfort of occupants. Prior research has shown cooling energy savings from use of a thermal comfort control methodology ranging from 10 to 85%. The present research advances prior research to enable thermal comfort control in residential buildings using a smart Wi-Fi thermostat. “Fanger’s Predicted Mean Vote model” is used to define thermal comfort. A machine learning model leveraging historical smart Wi-Fi thermostat data and outdoor temperature is trained to predict indoor temperature. A Long Short-Term-Memory neural network algorithm is employed for this purpose. The model considers solar heat input estimations to a residence as input features. The results show that this approach yields a substantially improved ability to accurately model and predict indoor temperature. Secondly, it enables a more accurate estimation of potential savings from thermal comfort control. Cooling energy savings ranging from 33 to 47% are estimated based upon real data for variable energy effectiveness and solar exposed residences.

scholarly journals Field Study Of A Radiant Heating System For Sleep Thermal Comfort And Potential Energy Saving

2021 ◽  
Author(s):  
Christopher L. K. Wang
Keyword(s):  
Potential Energy ◽  
Thermal Comfort ◽  
Energy Saving ◽  
Energy Savings ◽  
Thermal Environment ◽  
Residential Buildings ◽  
Thermal Conditions ◽  
Heating System ◽  
The Body ◽  
Radiant Temperature

As sleep is unconscious, the traditional definition of thermal comfort with conscious judgment does not apply. In this thesis sleep thermal comfort is defined as the thermal condition which enables sleep to most efficiently rejuvenate the body and mind. A comfort model was developed to stimulate the respective thermal environment required to achieve the desired body thermal conditions and a new infrared sphere method was developed to measure mean radiant temperature. Existing heating conditions according to building code conditions during sleeping hours was calculated to likely overheat a sleeping person and allowed energy saving potential by reducing nighttime heating set points. Experimenting with existing radiantly and forced air heated residential buildings, it was confirmed that thermal environment was too hot for comfortable sleep and that the infrared sphere method shows promise. With the site data, potential energy savings were calculated and around 10% of energy consumption reduction may be achieved during peak heating.

scholarly journals Demand Control Strategies of a PCM Enhanced Ventilation System for Residential Buildings

2020 ◽  
Vol 10 (12) ◽  
pp. 4336
Author(s):  
Yue Hu ◽  
Per Kvols Heiselberg ◽  
Tine Steen Larsen
Keyword(s):  
New York ◽  
Energy Storage ◽  
Energy Saving ◽  
Energy Savings ◽  
Control Strategies ◽  
Residential Buildings ◽  
Ventilation System ◽  
Airflow Rate ◽  
Energy Saving Potential ◽  
Demand Control

A ventilated window system enhanced by phase change material (PCM) has been developed, and its energy-saving potential examined in previous works. In this paper, the ventilation control strategies are further developed, to improve the energy-saving potential of the PCM energy storage. The influence of ventilation airflow rate on the energy-saving potential of the PCM storage is firstly studied based on an EnergyPlus model of a sustainable low energy house located in New York. It shows that in summer, the optimized ventilation airflow rate is 300 m3/h. The energy-saving of utilizing a ventilated window with PCM energy storage is 10.1% compared to using a stand-alone ventilated window, and 12.0% compared to using a standard window. In winter, the optimized ventilation airflow rate is 102 m3/h. The energy-saving of utilizing a ventilated window with PCM energy storage is 26.6% compared to using a stand-alone ventilated window, and 32.8% compared to using a standard window. Based on the optimized ventilation airflow rate, a demand control ventilation strategy, which personalizes the air supply and heat pump setting based on the demand of each room, is proposed and its energy-saving potential examined. The results show that the energy savings of using demand control compared to a constant ventilation airflow rate in the house is 14.7% in summer and 30.4% in winter.

scholarly journals Self-Learning Algorithm to Predict Indoor Temperature and Cooling Demand from Smart WiFi Thermostat in a Residential Building

2020 ◽  
Vol 12 (17) ◽  
pp. 7110
Author(s):  
Kefan Huang ◽  
Kevin P. Hallinan ◽  
Robert Lou ◽  
Abdulrahman Alanezi ◽  
Salahaldin Alshatshati ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
Energy Savings ◽  
Dynamic Models ◽  
Short Term Memory ◽  
Learning Algorithm ◽  
Peak Load ◽  
Back Propagation ◽  
Residential Building ◽  
Measured Temperature ◽  
Heating And Cooling

Smart WiFi thermostats have moved well beyond the function they were originally designed for; namely, controlling heating and cooling comfort in buildings. They are now also learning from occupant behaviors and permit occupants to control their comfort remotely. This research seeks to go beyond this state of the art by utilizing smart WiFi thermostat data in residences to develop dynamic predictive models for room temperature and cooling/heating demand. These models can then be used to estimate the energy savings from new thermostat temperature schedules and estimate peak load reduction achievable from maintaining a residence in a minimum thermal comfort condition. Back Propagation Neural Network (BPNN), Long-Short Term Memory (LSTM), and Encoder-Decoder LSTM dynamic models are explored. Results demonstrate that LSTM outperforms BPNN and Encoder-Decoder LSTM approach, yielding and a MAE error of 0.5 °C, equal to the resolution error of the measured temperature. Additionally, the models developed are shown to be highly accurate in predicting savings from aggressive thermostat set point schedules, yielding deep reduction of up to 14.3% for heating and cooling, as well as significant energy reduction from curtailed thermal comfort in response to a high demand event.

scholarly journals Thermochromic Paints on External Surfaces: Impact Assessment for a Residential Building through Thermal and Energy Simulation

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1912 ◽  
Author(s):  
Vasco Granadeiro ◽  
Margarida Almeida ◽  
Tiago Souto ◽  
Vítor Leal ◽  
João Machado ◽  
...  
Keyword(s):  
Energy Use ◽  
Energy Savings ◽  
Residential Buildings ◽  
Residential Building ◽  
Cost Effective ◽  
Physical Models ◽  
Indoor Temperature ◽  
Heating And Cooling ◽  
Step Transition ◽  
Linear Manner

This work addresses the effect of using thermochromic paints in residential buildings. Two different thermochromic paint types were considered: One that changes properties through a step transition at a certain temperature, and another that changes properties in a gradual/linear manner throughout a temperature range. The studied building was a two-floor villa, virtually simulated through a digital model with and without thermal insulation, and considering thermochromic paints applied both on external walls and on the roof. The performance assessment was done through the energy use for heating and cooling (in conditioned mode), as well as in terms of the indoor temperature (in free-floating mode). Three different cities/climates were considered: Porto, Madrid, and Abu Dhabi. Results showed that energy savings up to 50.6% could be reached if the building is operated in conditioned mode. Conversely, when operated in free-floating mode, optimally selected thermochromic paints enable reductions up to 11.0 °C, during summertime, and an increase up to 2.7 °C, during wintertime. These results point out the great benefits of using optimally selected thermochromic paints for obtaining thermal comfort, and also the need to further develop stable and cost-effective thermochromic pigments for outdoor applications, as well as to test physical models in a real environment.

scholarly journals Upgrading the Smartness of Retrofitting Packages towards Energy-Efficient Residential Buildings in Cold Climate Countries: Two Case Studies

Buildings ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 200 ◽  
Author(s):  
Laurina C. Felius ◽  
Mohamed Hamdy ◽  
Fredrik Dessen ◽  
Bozena Dorota Hrynyszyn
Keyword(s):  
Thermal Comfort ◽  
Life Cycle Cost ◽  
Energy Savings ◽  
Residential Buildings ◽  
Cost Effective ◽  
Energy Performance ◽  
Building Envelope ◽  
Heat Losses ◽  
Cold Climate ◽  
The Impact

Improving the energy efficiency of existing buildings by implementing building automation control strategies (BACS) besides building envelope and energy system retrofitting has been recommended by the Energy Performance of Buildings Directive (EPBD) 2018. This paper investigated this recommendation by conducting a simulation-based optimization to explore cost-effective retrofitting combinations of building envelope, energy systems and BACS measures in-line with automation standard EN 15232. Two cases (i.e., a typical single-family house and apartment block) were modeled and simulated using IDA Indoor Climate and Energy (IDA-ICE). The built-in optimization tool, GenOpt, was used to minimize energy consumption as the single objective function. The associated difference in life cycle cost, compared to the reference design, was calculated for each optimization iteration. Thermal comfort of the optimized solutions was assessed to verify the thermal comfort acceptability. Installing an air source heat pump had a greater energy-saving potential than reducing heat losses through the building envelope. Implementing BACS achieved cost-effective energy savings up to 24%. Energy savings up to 57% were estimated when BACS was combined with the other retrofitting measures. Particularly for compact buildings, where the potential of reducing heat losses through the envelope is limited, the impact of BACS increased. BACS also improved the thermal comfort.

scholarly journals Development of strategy for combined smart ventilated window and PCM energy storage control for residential building energy saving

2021 ◽  
Vol 2042 (1) ◽  
pp. 012161
Author(s):  
Yue Hu ◽  
Per Kvols Heiselberg
Keyword(s):  
Energy Storage ◽  
Thermal Comfort ◽  
Energy Saving ◽  
Control Strategy ◽  
Energy Savings ◽  
Control Strategies ◽  
Average Energy ◽  
Residential Building ◽  
Energy Performance ◽  
Before And After

Abstract The paper studies the energy renovation of a residential building with new façade solutions combining smart ventilated window (VW) and PCM energy storage and the corresponding control strategy to ensure energy savings. The study is carried out by Energyplus modelling comparing the energy consumption and thermal comfort of an apartment before and after renovation. A detailed control strategy is introduced and simulated. The modelling results of the apartment before and after retrofit indicate that with the designed control strategies, the average energy saving percentage of the apartment with PCM energy storage and VW compared to the apartment without PCM energy storage and VW is 29%. The rooms with PCMVWs achieve higher energy saving than the rooms with only VWs. The PCM energy storage improves energy performance of the VWs for both heating and cooling seasons. With the renovation, the thermal comfort of all the rooms are improved for cooling season.

scholarly journals Effect of insulation on indoor thermal comfort in a detached house with a floor heating system

2019 ◽  
Vol 111 ◽  
pp. 02049 ◽  
Author(s):  
Qianwen Guo ◽  
Ryozo Ooka ◽  
Wonseok Oh ◽  
Wonjun Choi ◽  
Doyun Lee
Keyword(s):  
Thermal Comfort ◽  
Thermal Insulation ◽  
Energy Savings ◽  
Residential Buildings ◽  
Insulation Material ◽  
Indoor Thermal Comfort ◽  
Detached House ◽  
The Impact ◽  
Floor Heating ◽  
Floor Temperature

Appropriate insulation materials, with unique physical properties and of moderate thickness, are essential for energy savings in residential buildings. However, the impact of thermal insulation on indoor thermal comfort with floor heating systems has not been studied extensively. In this study, simulations of a typical Japanese detached house were conducted with four different thicknesses of insulation material in the walls, ceiling, and floor to estimate the mean air temperature (MAT), mean radiant temperature (MRT), floor temperature, predicted mean vote (PMV) and predicted percentage of dissatisfied (PPD). The results showed that increasing the thickness of thermal insulation increased the MAT and MRT by 1.4 – 4.0 ℃ and 1.3 – 4.4 ℃, respectively. Moreover, as the thickness of the thermal insulation increased, the floor temperature rose and exhibited smaller fluctuations. Finally, it was found that increasing the thickness of thermal insulation improved the indoor thermal comfort environment, as evidenced by an increase in the PMV from –1.0 to 0.3, and a decrease in the PPD from 25.1% to 9.5%.

scholarly journals Field Study Of A Radiant Heating System For Sleep Thermal Comfort And Potential Energy Saving

2021 ◽  
Author(s):  
Christopher L. K. Wang
Keyword(s):  
Potential Energy ◽  
Thermal Comfort ◽  
Energy Saving ◽  
Energy Savings ◽  
Thermal Environment ◽  
Residential Buildings ◽  
Thermal Conditions ◽  
Heating System ◽  
The Body ◽  
Radiant Temperature

As sleep is unconscious, the traditional definition of thermal comfort with conscious judgment does not apply. In this thesis sleep thermal comfort is defined as the thermal condition which enables sleep to most efficiently rejuvenate the body and mind. A comfort model was developed to stimulate the respective thermal environment required to achieve the desired body thermal conditions and a new infrared sphere method was developed to measure mean radiant temperature. Existing heating conditions according to building code conditions during sleeping hours was calculated to likely overheat a sleeping person and allowed energy saving potential by reducing nighttime heating set points. Experimenting with existing radiantly and forced air heated residential buildings, it was confirmed that thermal environment was too hot for comfortable sleep and that the infrared sphere method shows promise. With the site data, potential energy savings were calculated and around 10% of energy consumption reduction may be achieved during peak heating.

scholarly journals Total Solar Reflectance Optimization of the External Paint Coat in Residential Buildings Located in Mediterranean Climates

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2729
Author(s):  
Tiago Souto ◽  
Margarida Almeida ◽  
Vítor Leal ◽  
João Machado ◽  
Adélio Mendes
Keyword(s):  
Thermal Performance ◽  
Energy Savings ◽  
Residential Buildings ◽  
Thermal Characteristics ◽  
Residential Building ◽  
Building Envelope ◽  
R Software ◽  
Indoor Temperature ◽  
Solar Reflectance ◽  
Parametric Studies

This work addresses the effect of the total solar reflectance (TSR) value of paints applied in residential buildings upon their thermal performance. A semi-detached residential building was modeled in the ESP-r software, and taken as the basis for parametric studies which assessed the effects of variations in (i) the TSR values; (ii) the thermal characteristics of the building envelope; (iii) the location/climate; and: (iv) the way how the indoor temperature is controlled. The parametric studies were used to find optimal TSR values for each combination of Location + Building envelope characteristics (mainly the existence of thermal insulation). It was concluded that paints having a carefully chosen TSR value lead to better indoor thermal temperatures if the buildings have no mechanical heating or cooling, or to energy savings of up to 32% if they do.

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