Impact on primary school classrooms temperature and ventilation from using a roof-mounted solar air heater: a winter case study in New Zealand

Classrooms that rely on natural ventilation are often under ventilated in winter. However, conventional mechanical ventilation is prohibitively expensive for schools. This study investigates the impact on temperature and ventilation in New Zealand (NZ) primary classrooms in winter, with the intervention of operating a roof-mounted solar air heater (SAH). This study was carried out in NZ school Term 3 (from end July to end September) in 2013 and 2014. Two adjacent classrooms (Room 1 and Room 2) from one school participated. These two classrooms had very similar construction characteristics and population characteristics. In 2013, baseline monitoring was conducted. In 2014, Room 1 was the control, Room 2 was the treatment. Ambient air is heated by the SAH, and this heated air was delivered to the treatment classroom. Heater use hours, temperature levels and carbon dioxide (CO2) concentrations in both classrooms were measured. The ventilation rate was estimated using traces gas decay techniques. In 2013, the temperature levels in Room 1 (21.8 ºC ± 1.4 ºC) were statistically significantly lower (P < 0.01) than in Room 2 (23.9 ºC ± 1.5 ºC), with the temperature difference of 2.1 ºC. In 2014, the temperature difference between Room 2 (treatment) and Room 1 (control) increased to 2.7 ºC. However, the ratio of total daily heater use (Room2/Room1) reduced from 2.3 (227 hours difference) in 2013 to 1.9 (191 hours difference) in 2014. In 2013, CO2 levels in Room 1 were statistically significantly lower (P < 0.01) than in Room 2. In 2014, CO2 concentrations had no differences between these two classrooms. Between both classrooms, mean (±sd) ventilation rate was from 1.7 (± 1.5) to 2.6 (± 2.4) h-1, or from 3.0 (± 2.4) to 4.2 (± 3.9) l/s/person. This study indicates that operating a SAH played a positive role in increasing room temperature and ventilation rate, while reducing the consumption of purchased energy

Using a solar air heater to ventilate classrooms during the winter season in New Zealand: a potential alternative solution to assist during COVID 19 outbreaks

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Retrofitting solar air heaters in New Zealand schools – a randomized crossover intervention study

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https://www.sciencedirect.com/science/article/pii/S2352710223009816?CMX_ID=&SIS_ID=&dgcid=STMJ_AUTH_SERV_PUBLISHED&utm_acid=229490816&utm_campaign=STMJ_AUTH_SERV_PUBLISHED&utm_in=DM368176&utm_medium=email&utm_source=AC_

New Zealand (NZ) primary schools are inadequately ventilated in winter. The majority of NZ schools do not have mechanical ventilation systems and surveys show that only 30% of teachers are regularly opening windows in winter, therefore there is a need to study an affordable alternative ventilation method. This research was conducted to investigate the space heating and ventilation performance of a roof-mounted solar air heater (SAH) in NZ primary schools in winter. Field experiments over two winters were carried out in Palmerston North, NZ. A SAH was installed on the sun-facing roof of four schools in winter 2013 and six schools in winter 2014. During the experiment, the air temperature and air velocity were measured inside the classroom at the SAH outlet. Ambient weather conditions were measured by a local climate monitoring station. Across all schools and two winters, when the SAH was operated at 75% of the maximum fan speed, a mean (standard deviation, SD) level of the air temperature difference between the SAH outlet and inlet was 16.6 (10.4) °C, the mean (SD) volumetric flow rate of the outlet air was 34.0 (12.9) m3.h−1, and the mean (SD) level of thermal efficiency was 16 (11) %. Results showed that operating a roof-mounted SAH increased the indoor temperature and was useful to supplement the natural ventilation flow rate. This is the first study to investigate the field performance of a roof-mounted SAH in NZ primary schools over two winters. Results of this study provide insights for the use of solar energy without need for energy storage to heat and ventilate the classrooms

Additional file 1: Table S1: of [18F]Fluoromisonidazole PET in rectal cancer

Tumour AIC values from fitting 0-45min dynamic [18F]FMISO PET readings at baseline and week 2 to four different pharmacokinetic models. Table S2. Muscle AIC values from fitting 0-45 min dynamic [18F]FMISO PET readings at baseline and week 2 to four different pharmacokinetic models. Figure S1. Example of the ROI from which measurements were taken. Figure S2. Examples of TAC in tumour, blood and muscle at baseline over 0-4 h. Figure S3. Example of 0-45 min tumour TACs fitted to four different pharmacokinetic models. Figure S4. Example of 0-45 min muscle TACs fitted to four different pharmacokinetic models. Figure S5. The artwork shows examples of scatter & random events originating from the activity inside the bladder as a potential cause of spill-in counts inside the tumour. Figure S6. An example from the enema group showing transaxial PET/CT images at 2 and 4 h. AIC=akaike information criteria; min= minute; [18F]FMISO=[18F]fluoromisonidazole; PET=positron emission tomography; CRT=chemoradiotherapy; ROI=region of interest; TAC=time activity curve; h=hour; CT=computed tomography. (PDF 445 kb

He Kāinga Oranga: reflections on 25 years of measuring the improved health, wellbeing and sustainability of healthier housing

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