scholarly journals Air Distribution and Air Handling Unit Configuration Effects on Energy Performance in an Air-Heated Ice Rink Arena

Energies ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 693 ◽  
Author(s):  
Mehdi Taebnia ◽  
Sander Toomla ◽  
Lauri Leppä ◽  
Jarek Kurnitski
Keyword(s):  
Temperature Gradient ◽  
Air Temperature ◽  
Indoor Air ◽  
Energy Demand ◽  
Energy Performance ◽  
Air Distribution ◽  
Air Handling Unit ◽  
Cooling Coil ◽  
Indoor Conditions ◽  
Cooling Energy Demand

Indoor ice rink arenas are among the foremost consumers of energy within building sector due to their exclusive indoor conditions. A single ice rink arena may consume energy of up to 3500 MWh annually, indicating the potential for energy saving. The cooling effect of the ice pad, which is the main source for heat loss, causes a vertical indoor air temperature gradient. The objective of the present study is twofold: (i) to study vertical temperature stratification of indoor air, and how it impacts on heat load toward the ice pad; (ii) to investigate the energy performance of air handling units (AHU), as well as the effects of various AHU layouts on ice rinks’ energy consumption. To this end, six AHU configurations with different air-distribution solutions are presented, based on existing arenas in Finland. The results of the study verify that cooling energy demand can significantly be reduced by 38 percent if indoor temperature gradient approaches 1 °C/m. This is implemented through air distribution solutions. Moreover, the cooling energy demand for dehumidification is decreased to 59.5 percent through precisely planning the AHU layout, particularly at the cooling coil and heat recovery sections. The study reveals that a more customized air distribution results in less stratified indoor air temperature.

Thermal influence of sunshine and clothing on men walking in humid heat

1962 ◽  
Vol 17 (2) ◽  
pp. 311-316 ◽  
Author(s):  
F. N. Craig ◽  
E. G. Cummings
Keyword(s):  
Body Temperature ◽  
Temperature Gradient ◽  
Air Temperature ◽  
Indoor Air ◽  
Physiological Strain ◽  
Mean Body Temperature ◽  
Clothing Insulation ◽  
Air Temperatures ◽  
Rate Of Increase ◽  
Thermal Influence

For two men walking on a treadmill and wearing two layers of permeable clothing, the same physiological strain measured by the rate of increase in mean body temperature could be produced a) next to a building outdoors in the sunshine with an average air temperature of 85 F and humidity of 20 mm Hg and b) indoors with the same humidity and an air temperature 10 F higher. Under these conditions, the underwear was mainly wet with sweat and the outer layer was mainly dry. In comparable indoor tests on a third subject, the temperature of the underwear approached equilibrium 1 or 2 F lower than the temperature of the skin at air temperatures of 85 and 115 F. The error in calculating clothing insulation introduced by assuming the clothing to be dry is determined by the size and direction of the temperature gradient between skin and air. Adding 10 F to the indoor air temperature does not duplicate all the effects of sunshine. Submitted on September 15, 1961

scholarly journals The Impact of Infiltration on Heating Systems Dimensioning in Estonian Climate

2020 ◽  
Vol 172 ◽  
pp. 05004
Author(s):  
Raimo Simson ◽  
Taaniel Rebane ◽  
Martin Kiil ◽  
Martin Thalfeldt ◽  
Jarek Kurnitski
Keyword(s):  
Air Temperature ◽  
Indoor Air ◽  
Energy Performance ◽  
Simulation Software ◽  
Heat Losses ◽  
Climatic Data ◽  
Heating Systems ◽  
Air Temperatures ◽  
The Impact ◽  
Calculation Models

In this study we analysed the climatic conditions for infiltration estimation, different calculation methods and infiltration impact on heat load for heating systems dimensioning. To determine the wind conditions at low air temperatures of the coastal- and inland climatic zones in Estonia, 42 years of climatic data for Tallinn and Tartu were investigated. Calculation models with detailed air leakages were constructed of a single and two-storey detached house using dynamic simulation software IDA ICE. Simulations were carried out with the constructed calculation models, simulating various wind and sheltering conditions to determine the heating load of the buildings under measured wind conditions at the design external air temperatures. The simulation results were compared with results calculated with European Standard EN 12831:2017, methodology given in the Estonian regulation for calculating energy performance of buildings and with simulations using the default settings in IDA ICE based on the ASHRAE design day conditions. The percentage of heat losses caused by infiltration was found as 13-16% of all heat losses for the studied buildings. Simulations with historical climate periods showed that even in windy weather conditions the heating system dimensioned by the methods analysed may not be able to provide the required indoor air temperature. Analysis using the coldest and windiest periods showed that when systems are dimensioned by the studied methods, the highest decline in indoor air temperature occurs on the windiest day and not on the coldest day. The impact of high wind speeds and low sheltering conditions resulted up to 50% of all heat losses.

Numerical and experimental investigation of the influence of infrared reflective interior surfaces on building temperature distributions

2016 ◽  
Vol 26 (3) ◽  
pp. 355-367 ◽  
Author(s):  
Ali Joudi ◽  
Mathias Cehlin ◽  
Harald Svedung ◽  
Mats Rönnelid ◽  
Bahram Moshfegh
Keyword(s):  
Temperature Gradient ◽  
Surface Temperature ◽  
Air Temperature ◽  
Indoor Air ◽  
Surface Radiation ◽  
Radiative Properties ◽  
Temperature Distributions ◽  
Measurement Results ◽  
Building Heat ◽  
Reflective Surfaces

Radiative properties of interior surfaces can affect not only the building heat flux but also the indoor environment, the latter of which has not been thoroughly investigated. The aim of this study is to analyse the effect of surface emissivity on indoor air and surface temperature distributions in a test cabin with reflective interior surfaces. This was done by comparing experimental and simulation data of the test cabin with that of a normal cabin. This study employs transient computational fluid dynamics (CFD) using re-normalisation group (RNG) k– ε model, surface-to-surface radiation model and an enhanced wall function. Boundary conditions were assigned to exterior surfaces under variable outdoor conditions. The numerical and the measurement results indicate that using interior reflective surfaces will affect the indoor air temperature distribution by increasing the vertical temperature gradient depending on the time of the day. CFD simulations with high spatial resolution results show increased interior surface temperature gradients consistent with the increased vertical air temperature gradient. The influence of reflective surfaces is potentially greater with higher indoor surface temperature asymmetry. The vertical indoor air temperature gradient and surface temperatures are important parameters for indoor thermal comfort.

scholarly journals Comparison of Optimized and Conventional Models of Passive Solar Greenhouse—Case Study: The Indoor Air Temperature, Irradiation, and Energy Demand

Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5369
Author(s):  
Saleh Mohammadi ◽  
Esmail Khalife ◽  
Mohammad Kaveh ◽  
Amir Hosein Afkari Sayyah ◽  
Ali Mohammad Nikbakht ◽  
...  
Keyword(s):  
Air Temperature ◽  
Indoor Air ◽  
Energy Demand ◽  
Lightweight Concrete ◽  
Concrete Block ◽  
Coefficient Of Determination ◽  
Solar Greenhouse ◽  
Temperature Irradiation ◽  
Optimized Model ◽  
Passive Solar

This study was carried out to optimize a computational model of a new underground passive solar greenhouse to improve thermal performance, storage, and saving of heat solar energy. Optimized and conventional passive solar greenhouse were compared in regards of indoor air temperature, irradiation, and energy demand. Six different materials were used in the conventional model. In addition, TRNSYS software was employed to determine heat demand and irradiation in the greenhouse. The results showed that the annual total heating requirement in the optimized model was 30% lower than a conventional passive solar system. In addition, the resulting average air temperature in the optimized model ranged from −4 to 33.1 °C in the four days of cloud, snow, and sun. The average air temperature in the conventional passive solar greenhouse ranged from −8.4 to 24.7 °C. The maximum monthly heating requirement was 796 MJ/m2 for the Wtype87 model (100-mm lightweight concrete block) and the minimum value was 190 MJ/m2 for the Wtype45 model (50-mm insulation with 200-mm clay tile) in a conventional passive solar greenhouse while the monthly heating requirement estimated 126 MJ/m2 for the optimized greenhouse model. The predictability of the TRNSYS model was calculated with a coefficient of determination (R2) of 95.95%.

scholarly journals Preliminary Investigation on the Use of Exhaust Fans in Dwellings and Their Impact on Energy Balance

Proceedings ◽  
2019 ◽  
Vol 23 (1) ◽  
pp. 8
Author(s):  
Jean Rouleau ◽  
Louis Gosselin
Keyword(s):  
Indoor Air ◽  
Energy Demand ◽  
Residential Buildings ◽  
Preliminary Investigation ◽  
Residential Building ◽  
Energy Performance ◽  
Measured Data ◽  
Quebec City ◽  
Energy Performance Of Buildings ◽  
Canada Data

Exhaust fans in residential buildings generate energy consumption first by the electricity that they require when operating, but also by extracting heat outside of the building. Nonetheless, these appliances are essential to ensure good indoor air quality. It is thus important to study how occupants in residential buildings use exhaust fans and to assess their impact on the energy performance of buildings. In this paper, a preliminary analysis on these two topics is made based on measured data recorded from a multi-residential building located in Quebec City, Canada. Data show that the use of exhaust fans is variable from a household to another. It was estimated that exhaust devices accounted for approximately 14% of the energy demand of the monitored building.

The Analysis of the Influence of Boundary Conditions on the Energy Performance of Houses

2014 ◽  
Vol 1020 ◽  
pp. 513-517
Author(s):  
Kateřina Kubenková ◽  
Barbora Hrubá ◽  
Michal Kraus ◽  
Darja Kubečková
Keyword(s):  
Energy Consumption ◽  
Boundary Conditions ◽  
Air Temperature ◽  
Indoor Air ◽  
Energy Intensity ◽  
Statistical Evaluation ◽  
Energy Performance ◽  
Final Energy ◽  
The Individual

The analysis focuses on the influence of boundary conditions on the final energy intensity of selected groups of houses. The individual energy intensity will be set for the selected buildings. For these buildings, the standard boundary conditions will change (indoor air temperature). The deviation values of resulting energy consumption will be defined by statistical evaluation.

Indoor air distribution in a room with underfloor air distribution and chilled ceiling: Effect of ceiling surface temperature and supply air velocity

2019 ◽  
Vol 29 (2) ◽  
pp. 151-162 ◽  
Author(s):  
Jie Gao ◽  
Haichao Wang ◽  
Xiaozhou Wu ◽  
Fenghao Wang ◽  
Zhen Tian
Keyword(s):  
Surface Temperature ◽  
Air Temperature ◽  
Indoor Air ◽  
Residential Buildings ◽  
Air Distribution ◽  
Cooling Load ◽  
Air Velocity ◽  
Underfloor Air Distribution ◽  
Chilled Ceiling ◽  
Cooling Loads

An underfloor air distribution (UFAD) system integrated with a chilled ceiling (CC) cooling system may be a potential advanced heating, ventilation and air conditioning system in modern non-residential buildings with high sensible cooling loads. This article presents an experimental study concerning the effect of ceiling surface temperature and supply air velocity on the indoor air distribution in a room with UFAD as the internal and external sensible cooling loads change. The vertical distributions of indoor air temperature, air velocity and contaminant (CO2) concentration were evaluated by vertical air temperature difference (VATD), turbulence intensity (TI) and contaminant removal effectiveness (CRE), respectively. The results showed that the average VATD, TI and CRE levels were 0.5°C–1.0°C, 31%–41% and 0.85–1.06 when both internal and external sensible cooling loads were 41.5 W/m2. These evaluation indices varied clearly when the external sensible cooling load increased from 41.5 W/m2 to 69.5 W/m2, whereas they remained almost the same when the internal sensible cooling load increased from 41.5 W/m2 to 69.5 W/m2. The maximum TI coincided with the minimum CRE under the condition of a constant sensible cooling load. Moreover, an air diffusion performance index clearly reduced with an increase in the heat removal effectiveness. It is recommended that it is important to balance the indoor air quality and energy consumption in a room with UFAD + CC.

scholarly journals A Study and Proposal for Applying Cooling Effect of Hybrid Ventilation to the Monthly Energy Demand Calculation Method in Korea

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 7420
Author(s):  
Sangtae No
Keyword(s):  
Calculation Method ◽  
Energy Demand ◽  
Residential Buildings ◽  
Energy Performance ◽  
Reduction Factor ◽  
Air Cooling ◽  
Floor Plans ◽  
Hybrid Ventilation ◽  
Energy Simulations ◽  
Cooling Energy Demand

Countries around the world develop and use software based on the monthly calculation method of DIN V 18599:2007 and EN ISO13790 for building energy performance evaluations. The purpose of this study is to propose a method that can consider the effect of reducing cooling energy demand by hybrid ventilation outdoor air cooling in monthly calculation method-based software. For ventilation simulation, some representative floor plans and area types of Korean residential buildings were established through literature research. A number of dynamic energy simulations were performed for various building orientations, heights, and opening factors. Based on the simulation results, a nomograph that can calculate the cooling energy demand reduction factor according to hybrid ventilation that can be applied to the ventilation heat transfer coefficient is proposed.

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.

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