scholarly journals Assessing the Energy, Indoor Air Quality, and Moisture Performance for a Three-Story Building Using an Integrated Model, Part Three: Development of Integrated Model and Applications

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5648
Author(s):  
Seyedmohammadreza Heibati ◽  
Wahid Maref ◽  
Hamed H. Saber

The overall building performance depends mainly on the energy performance, indoor air quality, and moisture performance. In order to accurately calculate the building performance, the development of a model with the ability to integrate all three performances is required. In this research, a combination of three models namely EnergyPlus for energy, CONTAM for indoor air quality, and WUFI for moisture transport are used to develop an integrated model. The mechanism of this combination is based on the exchange of temperatures, airflows, and heating-cooling flows control variables between all three sub-models. By using the paired sample t-test, an integrated model is verified and its accuracy is validated. The accuracy of the integrated model is verified by the paired sample t-test. In order to analyze the accuracy of the integrated model in comparison with single models, four scenarios of airtight fan off, airtight fan on, leaky fan off, and leaky fan on are defined for a three-story-house subjected to three different climate cities of Montreal, Vancouver, and Miami. Percentage differences of simulated measures with the ASHRAE Standard are considered as the performance criteria. The simulated results by single and integrated models are compared and analyzed. Finally, the scenarios with the high performances are evaluated in terms of energy efficiency, indoor air quality, and moisture for Montreal, Vancouver, and Miami. Overall, it can be concluded that an integrated model should be developed.

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4915
Author(s):  
Seyedmohammadreza Heibati ◽  
Wahid Maref ◽  
Hamed H. Saber

In this paper, an integrated model that coupled CONTAM and WUFI was developed to assess the indoor air quality (IAQ), moisture, and thermal comfort performance. The coupling method of CONTAM and WUFI is described based on the exchange of airflow rate control variables as infiltration, natural and mechanical ventilation parameters between heat and moisture flow balance equations in WUFI and contaminant flow balances equations in CONTAM. To evaluate the predictions of the integrated model compared to single models of CONTAM and WUFI, four scenarios were used. These scenarios are airtight-fan off, airtight-fan on, leaky-fan off, and leaky-fan on, and were defined for a three-story house subjected to three different climate conditions of Montreal, Vancouver, and Miami. The measures of the simulated indoor CO2, PM2.5, and VOCs obtained by CONTAM; the simulated indoor relative humidity (RH), predicted percentage of dissatisfied (PPD), and predicted mean vote (PMV) obtained by WUFI; and those obtained by the integrated model are compared separately for all scenarios in Montreal, Vancouver, and Miami. Finally, the optimal scenarios are selected. The simulated results of the optimal scenarios with the integrated model method (−28.88% to 46.39%) are different from those obtained with the single models. This is due to the inability of the single models to correct the airflow variables.


Atmosphere ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 115
Author(s):  
Nishesh Jain ◽  
Esfand Burman ◽  
Samuel Stamp ◽  
Clive Shrubsole ◽  
Roderic Bunn ◽  
...  

Hospitals are controlled yet complex ecosystems which provide a therapeutic environment that promotes healing, wellbeing and work efficiency for patients and staff. As these buildings accommodate the sick and vulnerable, occupant wellbeing and good indoor environmental quality (IEQ) that deals with indoor air quality (IAQ), thermal comfort, lighting and acoustics are important objectives. As the specialist nature of hospital function demands highly controlled indoor environments, this makes them energy intensive buildings due to the complex and varying specifications for their functions and operations. This paper reports on a holistic building performance evaluation covering aspects of indoor air quality, thermal comfort, lighting, acoustics, and energy use. It assesses the performance issues and inter-relationships between IEQ and energy in a new building on a hospital campus in the city of Bristol, United Kingdom. The empirical evidence collated from this case study and the feedback received from the hospital staff help identify the endemic issues and constraints related to hospital buildings, such as the need for robust ventilation strategies in hospitals in urban areas that mitigate the effect of indoor and outdoor air pollution and ensuring the use of planned new low-carbon technologies. Whilst the existing guidelines for building design provide useful instructions for the protection of hospital buildings against ingress of particulate matter from outdoors, more advanced filtration strategies may be required to enact chemical reactions required to control the concentration levels of pollutants such as nitrogen dioxide and benzene. Further lessons for improved performance in operation and maintenance of hospitals are highlighted. These include ensuring that the increasingly available metering and monitoring data in new buildings, through building management systems, is used for efficient and optimal building operations for better IEQ and energy management. Overall, the study highlights the need for an integrated and holistic approach to building performance to ensure that healthy environments are provided while energy efficiency targets are met.


2019 ◽  
Vol 43 (2) ◽  
pp. 121-142
Author(s):  
Andrea Ferrantelli ◽  
Camilla Vornanen-Winqvist ◽  
Milla Mattila ◽  
Heidi Salonen ◽  
Jarek Kurnitski

Moisture excess in buildings constitutes a complex problem affecting indoor air quality, energy consumption and the lifetime of the building envelope. We investigate the effect on moisture transfer in structures as a positive pressure is applied inside the enclosure. It is found that, contrary to established belief, the positive pressure does not induce any negative effects on the structures’ moisture content in normally ventilated classrooms, even with high occupancy. Our case study consists of a school building in Finland, subject to temperature and relative humidity measurements after a small (5–7 Pa) positive pressure was realized through ventilation control. We first address analytically the moisture excess generated inside the classrooms for 14 days, using dynamical balance equations that account for both ventilation effects and occupants’ moisture release in the environment. It is found that the average moisture excess is very small, largely below 1 g/m3, even for ventilation rates that are half the design value. We also examine the moisture performance of the envelope, by addressing the moisture migration at upper and lower joints of the external walls for both measured and design values of the indoor absolute humidity (AH). A coupled numerical model of diffusion and convection shows that moisture accumulation in the envelope and the according stresses are negligible for any realistic AH values. This result is in agreement with field measurements at the school. In conclusion, it seems that applying a small overpressure in a well-ventilated school building during a standard service period resulted in no accumulation inside the external walls, even at high occupancy and with low ventilation. Remarkably, it slightly dried out the moisture content in structures under actual occupancy conditions. The positive pressure has accordingly no negative effects on moisture performance, and is capable to guarantee a good indoor air quality as well.


2016 ◽  
Vol 96 ◽  
pp. 277-284 ◽  
Author(s):  
V. Vasile ◽  
H. Petran ◽  
A. Dima ◽  
C. Petcu

2019 ◽  
Vol 24 (1) ◽  
pp. 7-16 ◽  
Author(s):  
Kalle Kuusk ◽  
Ahmed Kaiser ◽  
Nicola Lolli ◽  
Jan Johansson ◽  
Tero Hasu ◽  
...  

The European energy policy pushes the member states to transform building stock into nearly Zero-Energy Buildings (nZEB). This paper is focused on data collected from existing nZEB day-care centres,in order to be able to assess possible differences between predicted and actual energy and indoorenvironmental performance. Building structures, service systems and the indoor climate and energyperformance of five day-care centres were investigated in Estonia, Finland and Norway.Indoor climate condition measurements showed that in general, the thermal environment and indoor airquality corresponded to the highest indoor climate categories I and II (EN 15251). Building heating andventilation systems in studied buildings are working without major problems. Good indoor climate conditions were also reflected in the occupant satisfaction questionnaires. For most of the studied buildings, over 80%of the people marked all indoor environment condition parameters (thermal comfort, indoor air quality,acoustics, odour and illuminance) acceptable. The thermal environment in the cooling season was reportedproblematic because it was lower than the minimum temperature for indoor climate category II.Energy consumption analysis showed that measured real energy use was higher, or even significantlyhigher, than the energy use calculated during the design phase. Potential causes of the higher actualenergy consumption are caused by differences of measured and designed solutions, methodology of theenergy calculations, and the differences in user behaviour.Lessons learnt from previously constructed day-care centres can be utilised in the planning and designof new nZEBs.


Solar Energy ◽  
2003 ◽  
Author(s):  
Y. Cui ◽  
M. Liu

The Laboratory Air Handling Unit (LAHU) system is developed to improve building energy performance and indoor air quality (IAQ) in laboratory buildings. The LAHU system sends more (up to 100%) outside air to the office section first and re-circulates the office section air to the laboratory section. The theoretical model analysis shows that the LAHU system improves office section indoor air quality, uses less outside air during hot and cold weathers, and consumes significantly less thermal energy. The optimal control of outside air intake to office section maximizes IAQ improvement and thermal energy savings.


Energies ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4775 ◽  
Author(s):  
Seyedmohammadreza Heibati ◽  
Wahid Maref ◽  
Hamed H. Saber

In building applications, there is a dynamic interaction/coupling between the energy performance and the indoor air quality (IAQ) performance. Previously, the performance of energy consumption (EC) and IAQ has been evaluated independently. In this study, an energy performance model (EnergyPlus) and IAQ performance model (CONTAM: contaminant transport analysis) were simultaneously coupled as a new integrated simulation model in which the control variables were exchanged between the two models. Two scenarios were provided in this study for a three-story house. The first scenario addressed the effect of airtightness only. The second scenario, however, addressed the airtightness with an exhaust fan with an upgraded filter. In order to better analyze the accuracy of the simulations, the performance of the energy and IAQ were simulated independently using the EnergyPlus model and CONTAM model. Thereafter, the performance of the energy and IAQ were simulated using the present integrated simulation model. All simulations were conducted for the climatic conditions of Montreal and Miami. The results of the integrated simulation model showed that the exchange of control variables between both EnergyPlus and CONTAM produced accurate results for the performance of both energy and IAQ. Finally, the necessity of using the present integrated simulation model is discussed.


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