scholarly journals Modified Thermocouple Sensor and External Reference Junction Enhance Accuracy in Indoor Air Temperature Measurements

Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6577
Author(s):  
Hans Lundström ◽  
Magnus Mattsson
Keyword(s):  
Air Temperature ◽  
Indoor Air ◽  
Measurement Errors ◽  
Room Temperature ◽  
Temperature Measurements ◽  
Indoor Climate ◽  
Internal Reference ◽  
Indoor Temperature ◽  
External Reference ◽  
Reference Junction

Indoor air temperature belongs to the most important climatic variables in indoor climate research, affecting thermal comfort, energy balance, and air movement in buildings. This paper focuses on measurement errors when using thermocouples in indoor temperature measurements, with special attention on measurements of air temperature. We briefly discuss errors in thermocouple measurements, noting that, for temperatures restricted to indoor temperature ranges, a thermocouple Type T performs much better than stated in “standards”. When thermocouples are described in the literature, industrial applications are primarily considered, involving temperatures up to several hundred degrees and with moderate demands on accuracy. In indoor applications, the temperature difference between the measuring and the reference junction is often only a few degrees. Thus, the error contribution from the thermocouple itself is almost immeasurable, while the dominant error source is in the internal reference temperature compensation in the measuring instrument. It was shown that using an external reference junction can decrease the measurement error substantially (i.e., down to a few hundredths of a degree) in room temperature measurements. One example of how such a device may be assembled is provided. A special application of room temperature measurements involves measuring indoor air temperature. Here, errors, due to radiation influence on the sensor from surrounding surfaces, were surprisingly high. The means to estimate the radiative influence on typical thermocouples are presented, along with suggestions for modification of thermocouple sensors to lower the radiation impact and thereby improve the measurement accuracy.

scholarly journals An Online Grey-Box Model Based on Unscented Kalman Filter to Predict Temperature Profiles in Smart Buildings

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 2097 ◽  
Author(s):  
Marco Massano ◽  
Edoardo Patti ◽  
Enrico Macii ◽  
Andrea Acquaviva ◽  
Lorenzo Bottaccioli
Keyword(s):  
Kalman Filter ◽  
Internet Of Things ◽  
Air Temperature ◽  
Indoor Air ◽  
Unscented Kalman Filter ◽  
Box Model ◽  
Indoor Temperature ◽  
Thermal Dynamics ◽  
Thermal Network ◽  
Realistic Data

Nearly 40% of primary energy consumption is related to the usage of energy in Buildings. Energy-related data such as indoor air temperature and power consumption of heating/cooling systems can be now collected due to the widespread diffusion of Internet-of-Things devices. Such energy data can be used (i) to train data-driven models than learn the thermal properties of buildings and (ii) to predict indoor temperature evolution. In this paper, we present a Grey-box model to estimate thermal dynamics in buildings based on Unscented Kalman Filter and thermal network representation. The proposed methodology has been applied in two different buildings with two different thermal network discretizations to test its accuracy in indoor air temperature prediction. Due to a lack of a real-world data sampled by Internet of Things (IoT) devices, a realistic data-set has been generated using the software Energy+, by referring to real industrial building models. Results on synthetic and realistic data show the accuracy of the proposed methodology in predicting indoor temperature trends up to the next 24 h with a maximum error lower than 2 °C, considering one year of data with different weather conditions.

Effects of indoor temperature and background noise on floor impact noise perception

2018 ◽  
Vol 28 (4) ◽  
pp. 454-469 ◽  
Author(s):  
Wonyoung Yang ◽  
Myung-Jun Kim ◽  
Hyeun Jun Moon
Keyword(s):  
Air Temperature ◽  
Noise Level ◽  
Background Noise ◽  
Room Temperature ◽  
Thermal Environment ◽  
Subjective Evaluation ◽  
Adaptation Period ◽  
Indoor Climate ◽  
Impact Noise ◽  
Background Noise Level

This study investigates effects of room air temperature and background noise on the perception of floor impact noises in a room. Floor impact noises were recorded in apartment buildings and were presented in an indoor climate chamber with background noise for subjective evaluation. Thirty-two participants were subjected to all combinations of three thermal conditions (20%C, 25%C, 30%C and relative humidity 50%), four background noise types (Babble, Fan, Traffic and Water), three background noise levels (35 dBA, 40 dBA and 45 dBA) and four floor impact noises (Man Jumping, Children Running, Man Running and Chair Scraping). After a 1-h thermal adaptation period for each thermal condition, the participants were asked to evaluate their thermal and acoustic perceptions. Statistically significant effects were found for the room air temperature and background noise level on the perception of the floor impact noises. Noisiness, loudness and complaints of floor impact noise increased with increasing room temperature and background noise level. Annoyance of floor impact noise showed a peak in acceptable thermal environment for general comfort. Room air temperature was a dominant non-auditory factor contributing to floor impact noise annoyance, while the floor impact noise level influenced the floor impact noise loudness and the floor impact noisiness was almost equally affected by the room temperature, background noise level and floor impact noise level. Further investigation is needed to fully understand the combined perception of floor impact noise under various indoor environmental conditions.

Developing a Healthy, Comfortable and Energy-Saving Office Building

2012 ◽  
Vol 193-194 ◽  
pp. 45-50 ◽  
Author(s):  
Wen Pei Sung ◽  
Yi Rou Chi ◽  
Lin Jun Hong ◽  
Yu Kuang Zhao
Keyword(s):  
Indoor Air ◽  
Air Conditioning ◽  
Indoor Environment ◽  
Room Temperature ◽  
Office Building ◽  
Tropical Region ◽  
High Humidity ◽  
Indoor Temperature ◽  
Office Environment ◽  
Research Show

How to maintain a comfortable indoor environment without excessively relying on mechanical HVAC (Heating, Ventilation, and Air Conditioning) is a target to be pursued for future living requirements. The results obtained in this research show that in an office environment, the room temperature monitored during winter is close to the comfortable temperature; however, the office occupants feel that a little warmer indoor temperature is comfort. During summer, the occupants prefer cooler temperature than the comfort temperature. Additionally, Taiwan is located in sub-tropical region with hot and humid summer. Even if the room temperature is maintained in a comfortable range, the occupants still feel not so comfortable because of high humidity. Hence, reducing the room temperature below 23 °C is inferred to make occupants feel comfortable. Questionnaire survey indicates that ventilation is preferred by 30.9% of the respondents for summer and 43.3% for winter as an effective method to improve the stuffy indoor air.

scholarly journals Probabilistic modeling of the indoor climates of residential buildings using EnergyPlus

2017 ◽  
Vol 41 (3) ◽  
pp. 225-246 ◽  
Author(s):  
Elizabeth Buechler ◽  
Simon Pallin ◽  
Philip Boudreaux ◽  
Michaela Stockdale
Keyword(s):  
Relative Humidity ◽  
Air Temperature ◽  
Indoor Air ◽  
Air Conditioning ◽  
Residential Buildings ◽  
The United States ◽  
Climate Data ◽  
Indoor Climate ◽  
Oak Ridge ◽  
Simulation Engine

The indoor air temperature and relative humidity in residential buildings significantly affect material moisture durability, heating, ventilation, and air-conditioning system performance, and occupant comfort. Therefore, indoor climate data are generally required to define boundary conditions in numerical models that evaluate envelope durability and equipment performance. However, indoor climate data obtained from field studies are influenced by weather, occupant behavior, and internal loads and are generally unrepresentative of the residential building stock. Likewise, whole-building simulation models typically neglect stochastic variables and yield deterministic results that are applicable to only a single home in a specific climate. The purpose of this study was to probabilistically model homes with the simulation engine EnergyPlus to generate indoor climate data that are widely applicable to residential buildings. Monte Carlo methods were used to perform 840,000 simulations on the Oak Ridge National Laboratory supercomputer (Titan) that accounted for stochastic variation in internal loads, air tightness, home size, and thermostat set points. The Effective Moisture Penetration Depth model was used to consider the effects of moisture buffering. The effects of location and building type on indoor climate were analyzed by evaluating six building types and 14 locations across the United States. The average monthly net indoor moisture supply values were calculated for each climate zone, and the distributions of indoor air temperature and relative humidity conditions were compared with ASHRAE 160 and EN 15026 design conditions. The indoor climate data will be incorporated into an online database tool to aid the building community in designing effective heating, ventilation, and air-conditioning systems and moisture durable building envelopes.

scholarly journals Effects of PCM thermal properties and thermodiode panel (TDP) on buildings' energy demand and indoor temperature

2021 ◽  
Author(s):  
Mohammad Ebrahim Poulad
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Thermal Properties ◽  
Air Temperature ◽  
Indoor Air ◽  
Energy Demand ◽  
Temperature Fluctuations ◽  
Solar Thermal Energy ◽  
Indoor Temperature ◽  
Aluminium Sheets

The performance of a thermodiode panel (TDP) is investigated thoroughly. A phase change material (PCM) layer is integrated into the TDP. A TDP can transfer solar thermal energy into the building. Adding a PCM layer to the TDP adds capacity of storing solar energy into the TDP, and releases the stored energy when the sun goes down. The TDP is composed of dense foam, which is sandwiched between two aluminium sheets, and a thermosyphon passes through the foam layer. PCM layer is added to the condenser section of the TDP that is connected into the building envelope. PCM thermal properties and their effects on energy demand and indoor temperature are investigated on a typical building. The best melting point for the PCM was found to be a temperature in the middle of the set points (upper and lower). Quantitative indices are introduced to evaluate the effects of PCM on indoor air temperature fluctuations. PCM reduces the indoor air temperature fluctuations. Increasing thermal conductivity of PCM by an order of magnitude reduces about 2% annual energy demand of a building. Regarding convention heat transfer coefficient, by increasing the convective heat transfer coefficient at interior wall surface, the cooling demand slightly increases in summer. In winter, energy demand is sensitive to h-value with a positive correlation. Matlab codes developed using genetic algorithm to optimize the TDP sizes, i.e., thicknesses of three aluminium sheets, copper tube diameter and its thickness that makes the structure of thermosyphon. The optimum sizes found to be: plate thicknesses of 1.5 mm, 2.5 mm, and 2 mm and thermosyphon diameter and thickness of 32 mm and 9 mm, respectively, provide the maximum objective function (the best performance of the TDP). Thermal bridging of a TDP can be reduced 76 times by adding a piece of Teflon in the thermosyphon assembly. The integration can do both store and collect/gain solar thermal energy, which makes this panel a novel alternative for south walls. It is also shown that thermosyphon angle from the horizon shall be between 30 and 45 degree to have the best performance of the TDP.

Experimental Study of Indoor Air Quality for Cooling Condition Using ARDUINO System and PMV Index Testing the Effect of Heat Sources

2021 ◽  
pp. 2150021
Author(s):  
Sondes Ifa ◽  
Zied Driss
Keyword(s):  
Air Quality ◽  
Indoor Air ◽  
Cooling System ◽  
Infrared Camera ◽  
Heat Sources ◽  
Indoor Climate ◽  
Indoor Temperature ◽  
Human Thermal Comfort ◽  
The Impact ◽  
Made In

The human thermal comfort and the indoor healthy air quality in the houses and the offices have become a vital necessity, especially in the state of the development of the contagious virus as the COVID-19. In this study, the evaluation of the air distribution was investigated using a DHTT sensor connected to an ARDUINO card to benefit their simple use and their reasonable price comparing to other tools such as the infrared camera. The measurement of the temperature is made in 14 points divided on two directions: one near the sitting manikin and another in front with the cooling system. The impact of the heat sources was tested. In these conditions, the indoor temperature was examined for an empty room, a room occupied by one person and one computer, a room occupied by two persons and two computers and a lighted room. The experimental results prove that the indoor temperature increases with the multiplication of the heat sources. From a temperature equal to [Formula: see text]C, the PMV curves move away from the comfort zone and the indoor climate becomes hot.

scholarly journals Effects of PCM thermal properties and thermodiode panel (TDP) on buildings' energy demand and indoor temperature

2021 ◽  
Author(s):  
Mohammad Ebrahim Poulad
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Thermal Properties ◽  
Air Temperature ◽  
Indoor Air ◽  
Energy Demand ◽  
Temperature Fluctuations ◽  
Solar Thermal Energy ◽  
Indoor Temperature ◽  
Aluminium Sheets

The performance of a thermodiode panel (TDP) is investigated thoroughly. A phase change material (PCM) layer is integrated into the TDP. A TDP can transfer solar thermal energy into the building. Adding a PCM layer to the TDP adds capacity of storing solar energy into the TDP, and releases the stored energy when the sun goes down. The TDP is composed of dense foam, which is sandwiched between two aluminium sheets, and a thermosyphon passes through the foam layer. PCM layer is added to the condenser section of the TDP that is connected into the building envelope. PCM thermal properties and their effects on energy demand and indoor temperature are investigated on a typical building. The best melting point for the PCM was found to be a temperature in the middle of the set points (upper and lower). Quantitative indices are introduced to evaluate the effects of PCM on indoor air temperature fluctuations. PCM reduces the indoor air temperature fluctuations. Increasing thermal conductivity of PCM by an order of magnitude reduces about 2% annual energy demand of a building. Regarding convention heat transfer coefficient, by increasing the convective heat transfer coefficient at interior wall surface, the cooling demand slightly increases in summer. In winter, energy demand is sensitive to h-value with a positive correlation. Matlab codes developed using genetic algorithm to optimize the TDP sizes, i.e., thicknesses of three aluminium sheets, copper tube diameter and its thickness that makes the structure of thermosyphon. The optimum sizes found to be: plate thicknesses of 1.5 mm, 2.5 mm, and 2 mm and thermosyphon diameter and thickness of 32 mm and 9 mm, respectively, provide the maximum objective function (the best performance of the TDP). Thermal bridging of a TDP can be reduced 76 times by adding a piece of Teflon in the thermosyphon assembly. The integration can do both store and collect/gain solar thermal energy, which makes this panel a novel alternative for south walls. It is also shown that thermosyphon angle from the horizon shall be between 30 and 45 degree to have the best performance of the TDP.

scholarly journals Evaluation of the Integration of the Traditional Architectural Element Mashrabiya into the Ventilation Strategy for Buildings in Hot Climates

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 530
Author(s):  
Abdullah Abdulhameed Bagasi ◽  
John Kaiser Calautit ◽  
Abdullah Saeed Karban
Keyword(s):  
Air Temperature ◽  
Indoor Air ◽  
Thermal Environment ◽  
Field Tests ◽  
Climatic Conditions ◽  
Building Envelope ◽  
Indoor Temperature ◽  
Architectural Element ◽  
Cooling Methods

This paper reviewed related research works and developments on the traditional architectural element “mashrabiya” focusing on its history, design and structure, typology, and functions in hot climates. Moreover, the paper assessed the effect of the traditional mashrabiya on the indoor thermal environment and thermal comfort in a selected case study building. For this purpose, two similar rooms were investigated in a selected historic building with abundant mashrabiyas located in the Makkah Region, specifically in Old Jeddah, Saudi Arabia. The field tests were conducted during a typical hot summer month with two different configurations. The study demonstrated that opening the mashrabiya allowed more airflow into the room during the day and reduced the indoor temperature by up to 2.4 °C as compared to the closed mashrabiya. Besides, the building envelope played an important role in preventing the high fluctuation of the indoor air temperature, where the fluctuation of the rooms air temperature ranged between 2.1 °C and 4.2 °C compared to the outdoor temperature which recorded a fluctuation between 9.4 °C and 16 °C. The data presented here can be used for the future development of the mashrabiya concept and the potential incorporation with passive cooling methods to improve its design according to the requirements of modern buildings in hot climates. Moreover, further studies and tests on mashrabiyas under different climatic conditions are required. Also, the different strategies or materials can be incorporated with mashrabiyas in order to improve its thermal performance.

Simulation of the internal temperature in the Passol Laboratory, University of Debrecen

2012 ◽  
Vol 3 (1) ◽  
pp. 63-73 ◽  
Author(s):  
I. Csáky ◽  
F. Kalmár
Keyword(s):  
Temperature Variation ◽  
Air Temperature ◽  
Indoor Air ◽  
Storage Capacity ◽  
Building Structures ◽  
Internal Temperature ◽  
The One ◽  
Heavy Structure ◽  
East West ◽  
Made In

Abstract Nowadays the facades of newly built buildings have significant glazed surfaces. The solar gains in these buildings can produce discomfort caused by direct solar radiation on the one hand and by the higher indoor air temperature on the other hand. The amplitude of the indoor air temperature variation depends on the glazed area, orientation of the facade and heat storage capacity of the building. This paper presents the results of a simulation, which were made in the Passol Laboratory of University of Debrecen in order to define the internal temperature variation. The simulation proved that the highest amplitudes of the internal temperature are obtained for East orientation of the facade. The upper acceptable limit of the internal air temperature is exceeded for each analyzed orientation: North, South, East, West. Comparing different building structures, according to the obtained results, in case of the heavy structure more cooling hours are obtained, but the energy consumption for cooling is lower.

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