Ventilation measures for heritage office buildings in temperate climate for improvement of energy performance and IEQ

Non-destructive techniques (NDT) for the diagnosis of heritage buildings: Traditional procedures and futures perspectives

“…Only few studies have been found on CH buildings [6], but they confirm the results obtained in naturally ventilated buildings. Hamid et al [164] selected the concentration decay method in naturally ventilated CH buildings in Sweden to reduce the impact of the boundary conditions related to the presence of natural ventilation.…”

Natural and Mechanical Ventilation Concepts for Indoor Comfort and Well-Being with a Sustainable Design Perspective: A Systematic Review

“…In monitored classrooms in Beijing, both systems provided a too low temperature (below 18 • C) close to the beginning and the end of running heating period [105] 1.5 ach −1 MV suggested in nucleus-type hospitals, in order to provide comfort conditions [106] Personalized ventilation suggested in order to have thermal benefits for occupants [107] NV alone is not sufficient to ensure thermal comfort in a large semi-transparent ceiling ocean park case study [108] NV or HV can be adequate to provide thermal comfort [30,55,64,67,[109][110][111][112][113][114][115] During summer in Dubai, when NV is not sufficient, despite the too high outdoor temperature and too low wind, a reduction of 2-6 • C is possible in office buildings by NV [109] Definition of 7 • C outdoor temperature as lower boundary for NV to be ineffective [115] Definition of the range of applicability of NV between 10 • C and 25 • C of outdoor temperature [30] Preference for NV is often related with the higher degree of control of occupants [25,30,55,111,116] The negative effects of NV on productivity are under debate [111] A higher productivity by men workers when HV was used instead of MV was found in an office of Tokyo (Japan) [114] Dependence of thermo-hygrometric comfort on outdoor temperature and users' behavior [29,60,67] Due to global warming, NV use will decrease at warmer climates, simultaneously increasing in colder and mild areas [30] HV can be used when non-optimal conditions are achievable with NV only [67,109,117,118] Nighttime ventilation and night cooling can be exploited to enhance daily thermal comfort conditions…”

“…MV can help in providing optimal IAQ [25,60,107,[120][121][122][123][124] Higher IAQ satisfaction in NV buildings [113] Small or no difference in the perception with the two modes [125] Difference in the indoor environmental conditions perceived and actually present indoor [117] The presence of operable windows can provide a feeling of fresh air perception [55] Use of HV recommended, exploiting MV when not sufficient IAQ can be maintained with NV (e.g., too polluted outdoor conditions) [67,117,118] NV might not be sufficient in air-tight buildings [120] NV will benefit from low polluting mobility solutions such ass electric vehicles [30] Most standards focus on perceived IAQ and CO 2 concentration or energy consumption, but several comfort, performance, and health issues are often reported in buildings: necessity to move from a comfort-based to a health-based design. In this sense, benefits can be obtained by the use of personalized ventilation [107] Poorly designed or operated ventilation can lead to poor IAQ, which can cause virus airborne transmission due to dry conditions in winter: necessity the adoption of health-based ventilation design [25] CO 2 concentration reduction (1000 ppm, with a 1400 ppm decrease) in Spanish schools during the pandemic, due to the most frequent airing [119] Importance of having long and frequent airing periods with NV [67,118,121,126] Suggestion of automated windows and/or CO 2 and pollutants monitoring devices [117][118][119]122] Acoustic comfort…”

“…Conversely, the possibility to fully regulate temperature, airflow, and air velocity is a clear advantage of MV, of which performance is perfectly predictable and controllable if compared with NV, with positive implications on the IAQ [25,47,[57][58][59]. The use of heat recovery units can partially overcome the drawback of the larger amount of energy with respect to NV [60][61][62][63]. Finally, HV can be a good compromise between the two techniques, guaranteeing energy savings, but exploiting MV when proper IEQ conditions cannot be met with NV only [29,30,55,[64][65][66][67][68][69].…”

Assessment of Air Quality Perception and Its Effects on Users’ Thermal Comfort in Office Buildings

“…It is known that high CO2 concentration in indoor environments is an outcome of human metabolism and lack of indoor air exchange -mainly due to the air recirculation by air-conditioners [7,9]. One of the main strategies that contribute to the reduction of pollutants concentration and improvement of air quality is suitable air circulation in order to allow air exchange between indoor and outdoor environments [10][11][12][13]. For this purpose, natural ventilation with portable air cleaners and mechanical ventilation systems with particle filters are strategies indicated for removing indoor air pollutants [7,11].…”