Space heating systems and practices

Supplementary heating systems and heating practices varied across the households (Appendix N). Using heaters was a common and significant part of daily comfort practices in autumn and winter and spring. Participants reported that space heating was a significant proportion of overall household electricity use and cooling was a minor proportion .Residential energy use trajectories modelled for the Federal Government support this observation showing that in 2008 Tasmanians were using around 65 per cent of their residential energy use on space heating and in 2012 were

94 _{In 1999, 77 per cent of Tasmanian householder respondents to an ABS survey reported that their}

living areas received winter sunlight. The survey did not specify, however, how many hours of sunlight the living area received and no information was given on what other areas of dwellings had access to sunlight (Australian Bureau of Statistics 2002: 204). There is no other survey available detailing sun into living areas for Tasmanian houses.

95 _{The orientation of the house is difficult to adjust without substantial change to dwellings so is less}

likely to be adjusted in retrofits, but may be changed in major extensions. Planning laws are therefore needed to ensure orientation is prioritised when houses are first built and when they are renovated.

predicted to be using around 62 per cent,96 but negligible energy on cooling houses (Energy Efficient Strategies 2008). The large proportion of residential energy used for space heating makes it and related influences key concerns in dwelling

adaptations.

Heater systems

Among participant households, various heaters were used in different spaces, with a consequent need for different heating practices, variations in heat outputs and comfort levels. Main heaters were commonly positioned in living or dining areas. The four main types of heaters used in living and dining areas were wood, older style oil burning, electric conductive/convective heaters, and heat pump air conditioners. Extra heating in bedrooms and bathrooms was used as needed for short lengths of time, using small radiant fan heaters, stand-alone plug-in heaters, and body-scale heaters.97 Despite the variety of heating options available, heating could be problematic, especially where the living room heater was old or was not fit for purpose (which was common).

Heater replacements and upgrades had occurred in nine households. Terry was the only participant to regularly use a wood heater as his main heater and he found it very effective. Despite enjoying the heat that came from fire, Helen’s household replaced a wood fire with a radiant / fan electric heater to limit the children’s asthma. Lorraine and Robert also stopped regular use of their fire places when they installed heat pumps. Mary and Martin and Steve and Gwen had enjoyed wood fires in previous dwellings but chose not to install one in their current house because of the preparation and cleaning involved in wood fires. Others were deterred by the

pollution wood smoke caused. Terry’s semi-rural position meant the smoke pollution did not bother his neighbours.

96 _{During the 2008 interview period Tasmania was modelled to be using 10.6petajoules of energy for}

space heating from a total residential energy consumption of 16.4 petajoules (pJ). In 2012 heating is still modelled as using 10.1 pJ of energy in 2012 when the total residential energy use will be around 16.2 pJ (Energy Efficient Strategies 2008: 31, 38).

Seven households used heat pumps98 as their main space heaters because the heaters were seen to be energy efficient and convenient. Vanessa and Paul had used a GGAER rebate to purchase a heat pump. Frank and Olive had considered upgrading their main heaters to heat pumps. Participants reported that heat pumps heated rooms quickly, but said that wood fires felt better. Householders shared stories about their (and their friends’) uncomfortable experiences with the convective heat and noise from heat pumps. Some households had decided not to purchase heat pumps because they did not like the convective heat they had experienced at friends’ places. Mary and Martin were uncomfortable with the high levels of air movement of their heat pump, but realised that much discomfort could be overcome by using heater and air throw adjustments.

There was widespread confusion about the best way to use heat pumps. Several participants had been ‘advised’ by installers that the most energy efficient way to use a heat pump was to keep it running all the time at a low temperature (16°C). To participants this did not seem an energy efficient way to use a heat pump.99 Misinformation like this widespread ‘heat pump myth’ made it difficult for participants to settle into well-considered and efficient heating practices. Conductive and convective electric panel heaters and electric ‘Pureheat’ hybrid radiant and convective fan heaters were used as the main heaters in several houses. Those with electric panel heaters had them placed in different rooms along walls, whereas radiant/fan heaters were installed as single units and only in main living areas. Older style electric heaters, such as the one that Steve and Gwen had, could be energy-hungry. Gwen was keen to replace the heater because it was inefficient, expensive to run and did not fit with the aesthetics of their 1930s house. Electric radiant ceiling heat was used in Frederick and Keira’s living room and main

98 _{Heat pump describes a heater that uses air conditioner technology to extract heat from external air}

space and move the heat inside (or out). The heat transfer is achieved through the condensing and expanding gases, which requires a motor and compressor. Heat pumps use both outdoor heated air and electricity to create heated air inside, which can be more efficient than other electric forms of heating, which rely only on electricity by itself to do the heating.

99 _{I and other people involved with energy efficiency in Tasmania investigated the heat pump myth}

further. That the myth was incorrect was communicated by energy efficiency professionals at public forums in Greater Hobart (from personal notes taken on ‘Chills and Bills forums 2008).

bedroom. They felt the ceiling heat was very comfortable, but it appeared that it was a reasonably expensive system to run.

While Frank and Olive had investigated replacing older style oil-burning heaters in their living rooms, for various reasons they were still using them. Both had organised other space heating options but found they still returned to the oil heater in certain circumstances. For Frank it was when his granddaughter came (regularly) to stay and for Olive it was because she could prepay for the oil and found it kept her visitors comfortable.100

In bedrooms, studies and craft rooms people mainly kept stand-alone plug-in heaters, and small fan heaters (Del and Kirk had a wired-in panel heater). In bathrooms participants tended to use stand-alone plug-in heaters or radiant bar heaters on walls, or, on ceilings, would use ‘Ixl-tastics’—combined radiant lighting and ventilation heaters. These heaters were generally used for short bursts to keep people warm in the shower and to dry the room. One household mentioned that they considered their large television screen as a heater when they were using the television but found it overheated the room in summer!

Some households had their wired-in heating and hot water registered for a cheaper electricity tariff (42)101, and some did not, which created affordability challenges. Henry’s rental unit hot water was not registered for tariff 42 and heating was only supplied through a plug-in heater. Plug-in heaters were not eligible for tariff 42 prices. Helen’s heater was not on tariff 42 because her husband advised her there would not be enough of a cost saving to warrant calling out an electrician to install the new meter required to measure Tariff 42. In reality using Tariff 42 could reduce electricity costs from heater use by approximately 35%.102

100 _{Olive’s heating practices and changes to practices are explored further in chapter five.}

101 _{With the installation of a second meter and verification by a registered electrician, electricity used}

for hot water systems and wired-in heaters can be measured using this cheaper tariff. All other electricity used in residences is measured using another tariff (31).

102 _{In 2008 Tariff 31 cost approximately 17cents per kilowatt-hour and Tariff 42 cost approximately}

Householders had either renovated their heating systems or wanted to renovate their heating systems. Renovating wired-in heating systems or wood fire places was an expensive, complicated, technical and (semi) permanent change. Householders could not test the heater before buying it, with experience of the heater’s performance coming after purchase and installation.

Heating practices through seasons

Heating practices changed according to weather and householder activities and routines (Appendix N, Tables N-2 and N-3). There were two main strategies for heating main living and dining areas: either heaters were kept turned on with a thermostat and timer; or heaters were turned on and off according to need.

Heaters were not used by many households in summer, but their use at such times was instructive. Del and Kirk used their heater ‘a little bit’ in summer in the evenings. Being elderly, doing little exercise, and living in a house that had poor thermal resistance, meant they had trouble staying warm. Frederick and Keira used their thermostat-controlled ceiling heating on a low setting through summer. Without morning sun their house was often cold in the mornings. Frederick had health issues that limited his exercise levels and affected his ability to stay comfortable. Trent and his family, despite being active and healthy, used their heater in the kitchen in the morning because the room had little thermal resistance and received no morning sun. As the weather cooled down through autumn, all households (but one) began to use their heaters103, mainly in the evenings and mornings.104 Del and Kirk and Frederick and Keira continued to leave their heaters on thermostat control. Martin and Mary began using their heaters during the day whenever the weather became too cold. As with Frederick and Del, Mary required extra heating to stay comfortable because of chronic illness.

103 _{Lorraine and Robert were the last to begin using their heaters, but did so at the end of autumn.} 104 _{Despite cold mornings and cooling winds, overheating still occurred indoors on sunny afternoons}

Winter weather somewhat increased the length of time and the temperatures at which householders heated their houses. Most people used their heaters on low or moderate levels. Heating at high temperature was only used for short spurts on very cold days Mark and Del and Kirk were households who had less tolerance for variations in indoors temperatures and therefore more regularly used heaters when they were home (Appendix N, Table N-3). Mel started using the timer on her heat pump so that her house would be warm when she came home from work. Mark was using timers on his heaters. Lorraine and Robert only started heating their house in late winter but by winter were using all three heat pumps when they were at home.

Considering the physical dwelling features, most householders used their heating systems in what appeared a reasonable way. Heater use practices reflected strong affordability concerns and value bases of resourcefulness and environmental care. Most participants tried to reduce heater use wherever they could and at least ten households looked to use their heaters as little as they could. Major influences affecting heater use were: access to sunlight; time spent at home; occupant

timetables; exercise levels; health status; thermal resistance levels in housing shells; visitors in the house; resident animals’ needs; values underpinning and attitudes towards resource use; and, expectations related to thermal comfort. Ill health and disability created a clear need for more heating arguably because people were more sedentary and had poorer circulation and yet needed consistently comfortable

environments. Del and Kirk’s heater use, for example, was comparatively high due to ill health, disability, and lengthy periods of time spent at home.105 Mark’s home heater use was also comparatively high as his comfort expectations had been influenced by long periods of time spent in an air-conditioned office (heated to 22°C).106

105 _{Sixteen people in twelve of the participating households spent significant parts of their day at}

home. This was due to people working from home, managing chronic illness from home, parenting with young children, or being retired. The extended time at home impacted greatly on their energy bills but also may have benefited other comfort and energy efficient aspects (see chapters five and six).

106 _{The way comfort expectations are influenced by regular use of air-conditioned environments has}