Assessment of Building Automation and Control Systems in Danish Healthcare Facilities in the COVID-19 Era

A well-designed and properly operated building automation and control system (BACS) is key to attaining energy-efficient operation and optimal indoor conditions. In this study, three healthcare facilities of a different type, age, and use are considered as case studies to investigate the functionalities of BACS in providing optimal air quality and thermal comfort. IBACSA, the first-of-its-kind instrument for BACS assessment and smartness evaluation, is used to evaluate the current systems and their control functionalities. The BACS assessment is reported and analyzed. Then, three packages of improvements were implemented in the three cases, focusing on (1) technical systems enhancement, (2) indoor air quality and comfort, and (3) energy efficiency. It was found that the ventilation system domain is the best performer in the three considered cases with an overall score of 52%, 89% and 91% in Case A, B, and C,, respectively. On the other hand, domestic hot water domain scores are relatively low, indicating that this is an area where Danish healthcare facilities need to provide more concentration on. A key finding indicated by the assessment performed is that the three buildings score relatively very low when it comes to the impact criteria of energy flexibility and storage.

Assessment of productivity in different thermal working environments

In the paper the assessment of subjective productivity is presented as a function of indoor environment parameters on the example of students situated in the intelligent building. The volunteers in several different rooms (of various air temperature, humidity and CO2 concentration) filled in the questionnaires and assessed their current productivity. It might be related to both the educational performance and office work of low intensity. The physical parameters were measured with the microclimate high accuracy meter. The data obtained during the measurements of the indoor air parameters were compared with the subjective assessments of the volunteers and conclusions were drawn as to the impact of the working environment on the productivity of room users. The gathered experimental material might be useful for the building managers, so that proper indoor conditions within buildings might be applied that maximize productivity and working performance.

Innovative energy efficient thermal insulation to ensure indoor comfort in nZEB buildings

The paper presents the analysis of water and heat transfer through walls being thermally insulated with vegetal materials. The analysis identifies the risk for condense accumulation in the outer layers of external walls of a common residential building located in the coldest climatic regions of Romania. Different wall structures and insulation thicknesses are systematically considered with statistical extreme temperature and humidity outdoor values. Results are useful in designing nZEB individual houses with green and sustainable technologies that also provide energy savings and indoor conditions for good comfort and health in these desired building concept.

Biodynamic Lighting Conditions Preserve Nocturnal Melatonin Production in Pregnant Women During Hospitalization: A Randomized Prospective Pilot Study

Maternal circadian rhythms are important for maintaining maternal and fetal homeostasis. The maternal circadian system coordinates the internal clock of the fetus with environmental lighting conditions via the melatonin signal. The intensity and wavelength of daylight influence nocturnal melatonin production. This study aims to evaluate the effect of environmental lighting conditions on melatonin production in pregnant women with reduced mobility during hospitalization. We installed a human-centric lighting system with biodynamic effects (BDL, biodynamic lighting) in the patient rooms. The pregnant women in the patient rooms with standard indoor conditions served as a control group. The illuminance (lux) and dose of effective circadian irradiation (Hec) were recorded every 10 seconds by light dosimeters (Lucerne University, Switzerland) attached to the patients` clothing. We analyzed the illuminance status of 47 pregnant women with a median (IQR) gestational age of 29.9 (25.4-32.3) weeks of gestation. The median illuminance in the control group was significantly lower (p<0.05) than in the BDL group in the morning and afternoon from day 1 to 5. BDL patients had a significantly higher effective circadian irradiation in the morning. The effective circadian irradiation showed a significant daily rhythm only in the BDL group. The BDL group had a significantly higher melatonin production on day 3 (p=0.006) and day 6 (p=0.012) than the control group (median (IQR) 15840 (10140-22160) ng vs. 6141 (2080-11328) ng/n on day 3 and 18780 (11320-23562) ng vs. 6380 (3500-17600) ng on day 6). We have demonstrated that dramatically altered lighting conditions of hospitalized pregnant women may be optimized by installing biodynamic lighting systems in the patient rooms resulting in the maintenance of nocturnal melatonin production in pregnant women.

CONCEPTUAL FRAMEWORK OF CULTURAL BACKGROUND IN THE LIT ENVIRONMENT

In environmental terms, culture represents the climatic and indoor conditions people have experienced during a significant part of their life. Consequently, people exposed to different cultures might have different expectations of the lighting environment. Knowing the lighting expectations due to cultural experiences have numerous advantages; it could help meet the occupants’ needs and preferences and provide occupant satisfaction, reducing unnecessary energy consumption in the built environment. This paper aims to summarise a systematic review to create a conceptual framework of cultural background in the lit environment, which could help understand the impact of cultural background on daylight perception and expectation. This review highlighted that cultural background in lighting environment should be evaluated considering (1) the ethnicity and/or physiological characteristics of the individual eyes, (2) the area (luminance environment) where people used to live (3) the luminance environment they were recently exposed to and (4) the socio-cultural background of individuals. Future research should further test these components together and separately to investigate which component or combination is more influential on daylight perception.

Thermal performance of a low and medium temperature flat plate solar collector when controlling the output-input temperature difference and the tilt angle

This work presents a sensitivity analysis of the overall heat loss coefficient UL and the thermal efficiency η in low and medium temperature encapsulated flat plate solar collectors when controlling the output-input temperature difference ΔT and the angle of inclination β. The UL and η were determined using heat flow calorimetry at indoor conditions, emulating the solar radiation by the Joule effect and a PID control. The angle of inclination β range was 0-90°, and the ΔT range was 5.0-25.0 K. The ambient temperature and the mass flow rate were preset for each test. The UL experimental uncertainty was ±0.85 W/m2K for the inclination range of 0-45° and ±0.27 W/m2K for the inclination range of 45-90°. The results matched previous outcomes with a difference of up to 0.3 W/m2K. The UL behaved exponentially as β increased from horizontal to vertical position and linearly with ΔT. It was also observed that the UL and the efficiency were sensitive to the confined airflow variations. This model shows a sensitivity of low and medium temperature flat plate solar collectors, as the efficiency increased 140% when β was raised and 40% with ΔT.

Users’ Sensations in the Context of Energy Efficiency Maintenance in Public Utility Buildings

Research towards understanding the relationship between maintaining thermal comfort and energy efficiency in the public utility buildings was undertaken among 323 1st year students during class hours. Questionnaires surveys and measurements of indoor conditions were performed. The article identified students’ sensations and perceptions concerning indoor conditions. Temperature, relative humidity, air velocity and CO2 concentration measured to assess room conditions showed that the auditorium had almost comfortable conditions according to the literature guidelines. The indices used to assess students’ perceptions were: Thermal Sensation Vote (TSV), Thermal Preference Vote (TPV), Air Freshness Sensation Vote (AfSV), Air Movement Preference Vote (AmPV), and Relative Humidity Preference Vote (RHPV). The interpretation of these indicators showed that while the students’ requests for temperature changes and increased air movement are adequate for the air conditions in the room, the evaluation of stuffiness and requests for changes in humidity levels are surprising. Striving uncritically to meet the desired room parameters, according to the users votes, can lead to deterioration of the air and not only the increase in energy consumption but even waste it. Better understanding of users’ preferences and behaviour and further application of this knowledge indirectly aim at increasing energy efficiency in buildings.

Solar powered a wearable Electrocardiography (ECG) device with battery storage

In this article, we propose a wearable ECG device that can be continuously powered by both the sun and artificial lighting via battery charging. The ECG signal acquired by the AD8232 wearable sensor associated with Arduino Nano is sent to the smartphone via Bluetooth. To study the feasibility of solar powered wearable gadget, we have conducted several experiments to analyze the charging speed in both outdoor and indoor conditions. For fully charging 1200 mAh battery, the two solar panels require periods of 5 - 11 hours and 1698 - 1942 hours for outdoor and indoor conditions respectively. The study has shown that the indoor charging is far ineffective as compared to outdoor charging due to spectral mismatch. The current consumption of the device is low and the fully charged battery can act as a buffer to sustain the device for 48 ∼ 60 hours without the need of any further charging.

Thermal Impacts of the Internal Courtyards in Compound Houses: The Case of Tamale Metropolis

The research seeks to understand the effects of internal courtyards onthermal comfort conditions in compound houses in Ghana’s TamaleMetropolitan area. Internal courtyards are an integral part of the design ofcompound houses in this location.Their inclusion in building designs is largely as a point of domestic activitysuch as cooking and cleaning and also for social interaction. However, a lotof interchanges in thermal conditions between structures and the outdoorstake place within these internal courtyards. Various design details of thebuilding will engender different thermal responses of the internal courtyard.This paper assesses thermal comfort in compound houses as againstbungalow type houses in the Tamale Metropolis, Ghana by the applicationof the Predicted Percentage of Dissatisfied Persons (PPD) and PredictedMean Votes (PMV) model. This prototype compares with the InternationalStandards Organization (ISO) 7730 and American Society of Heating,Refrigeration and Air-Conditioning Engineers (ASHRAE) Standard 55(estimated values between 23˚C - 26˚C seen as the allowable temperatures).Ambient indoor conditions (dry bulb temperature and relative humidity)of five (5) buildings each from the two building typologies from wererecorded over a period of ten calendar months. These ambient conditionswere analyzed, consequently generating the Predicted Percentage ofDissatisfied Persons (PPD) and Predicted Mean Votes (PMV) recordings.The investigations uncovered relatively high PPD - PMV recordingsrelating to the Bungalow type buildings while the compound housesattune to the comfort zone. The Actual Mean Votes (AMV) of residentssuggests the two building typologies are all rated comfortable however; thecompound houses are rated above the bungalow type houses.