This section will explore the practices that residents undertake in their daily lives that also consume energy and water. Section 4.2.1
will focus on personal hygiene practices and how the meaning related to the practice influences the duration of the practice and corresponding water use. Section 4.2.2
examines the various technologies residents use to stay thermally comfortable pre- and post-occupancy in their homes. The average usage of these technologies and the influences on design that impact the resident’s comfort in the low-carbon development is also discussed. Finally, Section 4.2.3
examines the cooling practices of three households and their lifestyles and routines, highlighting the relevance of understanding the HSOP in energy demand.
4.2.1. Personal Hygiene Practices
Water for personal hygiene practices using showers is the largest water use inside the household [3
]. Previous research on personal hygiene has been conducted by [34
]. In examining the personal hygiene practices of residents in this research, a focus was taken on the meaning of performing the practice, as done previously in [38
]. Personal hygiene practices were usually performed by showering, with a few residents also having infrequent towel washes. Multiple meanings of showering affect the duration. This has been shown previously in [43
] and is again shown here in Figure 1
and Figure 2
. Figure 1
shows the changes to personal hygiene practice duration pre- and post-occupancy. The average practice duration pre-occupancy was 6 minutes, while the average practice duration post-occupancy is 4.4 minutes. This can be compared to previous results for shower duration by Australian residents with an average between 6 minutes and 8 minutes [65
]. The duration for all meanings decreased post-occupancy, except for cleanliness before leaving the home. This may be due to some residents not leaving their home as frequently in the low-carbon development due to working from home and therefore spending more time cleaning themselves when they do. The smallest change in meaning duration was for inter-activity cleanliness. Morning cleanliness also had only a small decrease in average duration. This highlights the interlocking of practices in resident’s lives and how this meaning for personal hygiene practices remains dependent on the timing of other practices and is not dependent on the practice itself. Unexpectedly, the relaxation meaning was not reported by the residents post-occupancy. This may be related to the change in technology, as most of the relaxation practices were undertaken via a bath pre-occupancy and bathtubs were not present post-occupancy or choosing other ways to relax, such as swimming in the ocean instead. The cleanliness meaning was also able to be categorised into either evening or morning for all residents post-occupancy due to more detailed completion of the personal hygiene diary by residents. These results highlight the influence that meaning has on personal hygiene practices and subsequent water use in the household.
shows the variation in the duration of showers post-occupancy for the 12 residents who provided this information through their personal hygiene diaries. Most showers are performed for either morning or evening cleanliness. There is generally a preference for either a morning or evening shower by the residents and not both. The showers that are taken for freshness are the shortest showers, while those situated between activities are also short. This relates to the interlocking of practices occurring in the home, whereby there are other practices requiring the residents’ attention and they only have a set amount of time available for showering. When there are less practices to perform during the day, residents will have longer showers. Cleanliness showers that occur before leaving the home for resident N are the longest showers as this resident reports that he rarely leaves the home and therefore spends more time on personal hygiene when he does. This is in line with the findings that the frequency of showering is dependent on practices such as work in resident’s lives [57
]. The resident in household D had a particularly long shower when she was dying her hair, which required her to turn the water on and off multiple times and make sure her hair was thoroughly washed. This is in contrast to her other showers, and the practice of dying her hair was not undertaken often. These results highlight the variations that can occur in personal hygiene practices for individuals dependent upon the meaning.
4.2.2. Ambient Heating and Cooling Practices
This section will discuss the ambient heating and cooling practices of the household’s pre- and post-occupancy. Heating and cooling practices demand the largest amount of energy in household practices [31
]. This section will focus on the technologies and skills needed by the residents to stay thermally comfortable and how this changes post-occupancy in WGV. It will also examine the indoor temperatures over the monitoring period and discuss comments raised by residents on how the performance of their heating and cooling practices has been influenced by the design of the dwellings.
outlines the different mechanical technologies used in heating and cooling practices by household’s pre- and post-occupancy, in addition to the use of clothing, blankets, hot water bottles or ice packs. Pre-occupancy, all homes practiced adaptive thermal comfort practices where residents take actions to restore or maintain their thermal comfort instead of relying on auxiliary heating or cooling. This includes opening and closing windows and doors, adding and removing clothing, using fans and taking hot or cold showers [49
]. Post-occupancy, residents have reported less use of auxiliary heating and cooling in their homes, with adaptive thermal comfort practices being sufficient. Some households have had to learn new skills in their thermal comfort practices when the technology available has changed. Evermore residents have switched to the use of a reverse cycle air conditioner for heating, which was also used for cooling by some. However, most of the Evermore residents report being thermally comfortable in the homes through winter and rarely using the reverse cycle air conditioner. In the houses, the two semi-detached houses (household F and M) have underfloor hydraulic heating, which was mostly adequate to keep them comfortably warm. However, this was a new technology and required them to learn new skills for the practice. Household G in the stand-alone house changed to a reverse cycle air conditioner for heating purposes and this was used throughout the winter, mostly in the afternoon and evenings. SHAC residents had the least changes to the technology used in their thermal comfort practices. As air conditioners or reverse cycle air conditioners were not included in the design of the apartments, the majority of residents have continued with the use of portable electric oil heaters (column heaters) and fans to stay comfortable, not requiring a change in skills to perform these practices. These results highlight the importance of understanding the technologies used within a practice before attempting to alter these.
shows the self-reported frequency of the use of heating and cooling systems by household’s post-occupancy in WGV. Evermore residents prefer the use of blinds and cross ventilation to keep a cool temperature in the apartments, with 80% reporting that they never use their heating and cooling. The use of ceiling fans or floor fans was reported across the day and the night and varied in frequency depending on how comfortable the resident was. The reverse cycle air conditioning systems were used by a retiree in Evermore, a shift worker in a house and a full-time worker in a house who has reported that he wants to be at a comfortable temperature to stay healthy and work productively at home. SHAC households do not have any air conditioning in their apartments for use in cooling or heating, which was a deliberate design decision by the developer and owner. Households all have ceiling fans in the living and bedroom areas, which are used as required, along with cross ventilation practices. These results highlight the differences in the use of technology by various residents.
In relation to heating, the only resident who reported using a heater in Evermore was a retiree who is home most of the day and night and uses the reverse cycle air conditioner system. In the houses, a shift worker will use the heating in the reverse cycle air conditioner system a few times a month, while the underfloor hydraulic heating was used periodically in the semi-detached houses. The use of a stand-alone heater was reported most frequently by the SHAC residents. Some households, particularly those in apartments where winter solar gain is partially obstructed by trees or other buildings, have reported being quite cold in SHAC. The use of a heater across all the dwellings was during the morning and evenings, unless the resident was home, then it occurred during the day also.
Households who reported the use of auxiliary heating or cooling with visitors in their home pre-occupancy [43
] now report that this is unnecessary because the thermal comfort of the dwelling is considered suitable, except for those who would normally use it for their own comfort. This has implications for considering the influence of social and societal norms when considering household energy use [69
The measured range of temperatures in the households living areas over a 3-month period from December 2018 to February 2019 is shown in Figure 4
. The thermal comfort range for living rooms in dwellings is considered to be between 20 and 25 °C, as compliant with the Australian National Construction Code [70
]. All dwellings recorded temperatures above 25 °C, while six dwellings recorded temperatures under 20 °C in their living areas. The lowest minimum outdoor temperature recorded during the monitoring period was 11.3 °C and the highest maximum outdoor temperature was 39 °C. It should be noted however that these temperatures were recorded during the Perth summer. Indoor temperatures in winter may fall below the recommended 20 °C in some dwellings. The largest range of temperatures experienced in a dwelling was 22.3 °C in household B during the monitoring period from December to February. This may be due to the fact that this apartment is located on the 2nd and 3rd story of the Evermore apartment complex and the 3rd floor does not have any adjourning apartments to assist in temperature regulation. It is also believed that the residents may have moved the sensor from its original position on the 2nd floor during monitoring. However, the range of temperatures in a similarly designed apartment, household C, indicates that these apartments, possibly due to their design and location on the 2nd and 3rd floor, feature a large range of temperatures. The dwelling with the smallest range of temperatures recorded was household O in the Evermore apartment complex. This apartment is located on the ground floor with a ground coupled slab which aides in thermal stability. It is also located between other apartments so is protected from extreme morning and afternoon sun by the neighbouring buildings. In relation to household practices, the occupants of households B and O pre-occupancy shared the same dwelling pre-occupancy and reported similar thermal comfort practices. This highlights the influence that design has on the temperatures of a home, regardless of occupant practices.
Additionally, there is only a 2.2 °C difference in the average range of indoor temperatures recorded across all the dwellings and all fall within the recommended range of 20 and 25 °C, except household H which has an average of 25.6 °C. This suggests that the design of the dwellings is sufficient to provide thermally comfortable temperatures. When residents were asked how often they felt thermally uncomfortable in their WGV dwellings, 75% or above answered that for less than once a month they feel too hot or too cold. This indicates that their adaptive thermal comfort practices, auxiliary technological use as needed and the design of the dwellings are mostly adequate for their perceived comfort, supporting the range of temperatures recorded.
There were some comments made by residents on certain design aspects that have hindered their thermal comfort, particularly in Evermore. Due to the location of the two apartment buildings with a common area in between, a wind tunnel is created between the apartments. Paired with the strong westerly breezes that are common in the afternoon in this location, some residents choose not to open their windows facing into the common area due to the noise created by the wind. This prevents cooling cross ventilation practices being fully employed and may be influencing the use of auxiliary cooling practices instead. In addition to this, the windows in all apartments above the ground floor are restricted from other than partial opening due to building requirements. While this is for safety reasons, this hinders the flow of sufficient air through the windows to adequately cool the apartments, particularly at night. Some residents have taken out the restrictors in the windows to allow for an increased breeze to come through, although this compromises the safety regulations. This is because they are more comfortable having windows open instead of using fans or an air conditioner for their cooling practices.
These results outline the importance of understanding the technology that residents use in their practices and how this changes when they move house. Some residents had to learn new skills to be thermally comfortable, particularly residents in households F and M, who had never used underfloor hydraulic heating previously. There were some equipment failures with the heating during the winter of 2018, which impacted how the residents remained comfortable. They reported reverting to the practices they performed pre-occupancy to stay warm without the use of a heater, including extra layers of clothes and the use of additional blankets. The change in these practices influences household energy demand patterns, which are important for the design of energy-efficient homes that rely on renewable energy.
4.2.3. Influence of Lifestyle and the HSOP on Cooling Practices
This section will examine the cooling practices of the three houses in the low-carbon development to highlight the influence of household variability in cooling practices in relation to the HSOP. Previous research has examined the connections between lifestyle and family composition and energy use [15
]. The thermal comfort range for dwellings living areas is considered to be between 20 and 25 °C, as compliant with the Australian National Construction Code [70
]. Figure 5
and Figure 6
show energy usage in households F, G and M during the hottest weekday and weekend day of the year during the monitoring period with complete data. These households were chosen because they are not apartments, which had some incomplete monitoring data. Households F and M are semi-detached houses and household G is a stand-alone house. Sunday 20 January had an outside minimum temperature of 21.8 °C and a maximum of 37.7 °C, while Thursday 7 February had an outside minimum temperature of 21 °C and a maximum of 36 °C. A hotter day occurred on Saturday 22 December 2018 (min 24.3 °C, max 39 °C). However, not all households had complete monitoring data for that day.
On Sunday 20 January, the energy use shows that all the households are using energy through the day. In all the households, there are peaks in the morning when the residents wake up, between 11.00 and 13.00 when they would be preparing lunch and completing household chores and then again in the evening around 17:00–19:00 when preparing dinner. Household G has the air conditioning on during the day due to the high energy use from 09:00–18:00. This is supported by the indoor temperature sensor which records the temperature to be between 23.5 and 24.5 °C during this time and 25°C or above outside of these times.
The energy use profile during a weekday, Thursday 7 February 2019 is markedly different for households F and M which consist of full-time, off-site (Monday to Friday) workers. There are small peaks in the morning between 05:00 and 07:00 when the residents wake up and prepare for work, then low energy use until the evening between 18:00 and 21:00 when the residents are returning home, preparing dinner and going to bed. In contrast, household G, which consists of a shift-worker and full-time student/part-time casual worker were home during the day and use energy throughout. There were similar peaks between 06:30 and 08:30 and 10:00 and 13:00 and then the air conditioner is switched on from 13:30 and 19:00. There is then an evening peak until 22:00 at night when the residents go to bed. The temperature in household G increases steadily from 25 to 29 °C during the morning before the air conditioner is turned on from 13:30 to 22:00, at 25 °C, when the temperature begins to rise again.
This data clearly shows the relationship between time of day, the HSOP and energy use. The HSOP recognises the interlocking of individual resident’s practices in the space of the home influencing the practices of others and resource consumption [38
]. In this example, the households where residents are out of the house on weekdays have low-energy use, with higher levels of consumption during the early morning and evening when the residents are home. This contrasts to the household with a resident home during the day due to differing work conditions, who is utilising energy through their practice of staying thermally comfortable. On a weekday where all the residents of the households are home and practices such as cleaning and washing are being undertaken, the energy use profiles of the households feature more peaks throughout the day.