Household Energy End-Use Project - Final report. Table of contents only. [Guide to index, illustrations, figures, and tables] [Document index] 1 INTRODUCTION 1 1.1 HEEP monitoring overview 1 1.2 HEEP in action 3 1.3 Further information 5 1.4 Acknowledgements 5 2 ENERGY END-USES 7 2.1 Changes in electricity use since 1971/72 7 2.2 Energy use distribution 10 2.3 Patterns of energy use 12 2.4 Energy consumption over the year 17 2.5 Appliance electricity use 18 2.6 Lighting 20 2.7 Changing official New Zealand energy statistics 21 3 HOUSEHOLD SELECTION 23 3.1 Sample size 23 3.2 Methodology 23 3.3 Participation rate 24 4 MONITORING AND DATA 28 4.1 What HEEP measured 28 4.2 Installation of monitoring equipment 29 4.3 Removal of equipment 30 4.4 Personnel and travel 30 4.5 Data collection equipment 31 4.6 Data processing 32 4.7 Specific fuel type processing 34 4.8 Data reliability 36 4.9 Meteorological data 39 4.10 Survey data 39 5 SAMPLE STRUCTURE AND ESTIMATION METHODS 42 5.1 General comments on bias 42 5.2 Large scale sample structure 42 5.3 Effect of spreading the survey over time 43 5.4 General principles of estimation 43 5.5 Monitoring within houses 44 5.6 Sampling of appliances for transponder monitoring 45 5.7 Estimation within houses 46 5.8 Application of the method in practice 47 5.9 The estimation technique in practice 50 6 HEERA MODEL DEVELOPMENT 54 6.1 Overview 54 6.2 Database design 55 6.3 HEERA Model 55 6.4 Excel and Access database tables 68 6.5 Graphic User Interface forms and VB procedures 69 6.6 Demonstration 69 7 WINTER TEMPERATURES 70 7.1 Historical comparison 70 7.2 Climate 71 7.3 Temperature distribution 72 7.4 Reported heating schedules by occupants 73 7.5 Reported heating seasons 76 7.6 Monitored heating seasons 78 7.7 House age 85 7.8 Thermal insulation 86 7.9 Temperature stratification 88 7.10 Winter temperature discussion 90 8 SUMMER TEMPERATURES 92 8.1 Maximum temperatures 94 8.2 Influences on indoor temperatures 96 8.3 Model of summer living room temperatures 98 8.4 Why are new houses warmer? 99 8.5 Temperature stratification in summer 101 8.6 Summer temperature discussion 101 9 EXTENSIVE TEMPERATURE MONITORING IN ONE HOUSE – CASE STUDY 103 9.1 The chosen typical house 103 9.2 Experimental set-up 103 9.3 Results 104 9.4 Vertical temperature distribution 106 9.5 Conclusions 108 10 PENSIONER HOUSING – TEMPERATURE CASE STUDY 109 10.1 Temperatures 109 10.2 Conclusions from the Hamilton study 111 11 SOCIAL ANALYSIS - INTRODUCTION 112 12 SOCIO-DEMOGRAPHIC CHARACTERISTICS OF HEEP HOUSEHOLDS 113 12.1 Household type 113 12.2 Household income 114 13 HOUSEHOLD VARIABLES AND FORECASTING AGGREGATE ENERGY USE 116 13.1 Income, living room temperatures and energy use 116 13.2 Size of household, living room temperatures and energy use 118 13.3 Household life stage, temperatures and energy use 120 13.4 The impact of social variables 121 14 FUEL POVERTY, MAORI HOUSEHOLDS AND SOLID FUEL USAGE 123 14.1 Fuel poverty 123 14.2 Temperature and energy use in Māori households 126 14.3 Impacts on Vulnerable Households of Moving Away from Solid Fuel 132 14.4 Energy and social policy – a critical interface 139 15 HOT WATER HEATING, DWELLING SIZE AND SUSTAINABILITY 141 15.1 Hot water heating – the shift to gas 141 15.2 House size, energy use and sustainability 147 16 MEASURING ENERGY USE IN WOOD AND SOLID FUEL HEATING 153 16.1 Introduction 153 16.2 Method 154 16.3 Comparison with Modera’s Equation 158 16.4 Results 159 16.5 Conclusions 160 17 LPG HEATER USE 162 17.1 Background 162 17.2 Heater numbers 162 17.3 Heater types 164 17.4 Data availability 165 17.5 Sample LPG heater use patterns 167 17.6 Patterns of use 169 17.7 LPG heater and dehumidifier ownership 173 18 EFFECT OF MANDATORY INSULATION ENERGY CONSUMPTION 174 18.1 Introduction and review 174 18.2 Household data 175 18.3 Statistical models of space heating 177 18.4 Summary of model results and discussion 180 18.5 Conclusions 181 19 ESTIMATING HEAT LOSS AND THERMAL MASS 182 19.1 STEM thermal model 182 19.2 Using STEM on HEEP houses in general 182 19.3 The STEM Model for a discrete time-series 184 19.4 Estimation of energy loads 185 19.5 Calibration by prediction of internal temperatures 185 19.6 STEM prediction 185 19.7 STEM results 186 19.8 Practical use of STEM model for HEEP analyses 187 20 HEEP APPLIANCE OWNERSHIP MODELS 188 20.1 Ownership data 188 20.2 Methods 188 20.3 Overview of models 189 20.4 Entertainment equipment 193 21 STANDBY AND BASELOAD IN NEW ZEALAND HOUSES 195 21.1 Introduction 195 21.2 Review 196 21.3 Standby & baseload data 196 21.4 Methodology 197 21.5 Results 199 21.6 Conclusions 202 22 FAULTY REFRIGERATION APPLIANCES 203 22.1 Review 203 22.2 Appliance data 204 22.3 Methodology 207 22.4 Results 208 22.5 Testing Cavallo and Mapp algorithm 209 22.6 Energy waste from faulty refrigeration appliances 210 22.7 Implications for energy savings programs 211 22.8 Greenhouse gas emissions 211 22.9 Discussion and conclusions 211 23 LOAD FACTORS AND REACTIVE POWER 213 23.1 Load factors 213 23.2 Reactive power 215 23.3 Measured reactive power and power factor 216 24 DOMESTIC HOT WATER 221 24.1 Introduction 221 24.2 Hot water today 221 24.3 Providing domestic hot water 222 24.4 International comparisons 224 24.5 Hot water Energy Use 228 24.6 DHW energy use distribution 230 24.7 System types 241 24.8 Estimates of wet-back energy heat inputs 243 24.9 Storage cylinders 244 24.10 Baths and showers 254 24.11 Shower water flow 258 24.12 Water temperatures 260 24.13 Improving cylinder thermal performance 269 24.14 Costs 270 24.15 Improving cylinder electricity efficiency 271 24.16 Cylinder wraps in reality 274 24.17 Reducing hot water energy use 275 24.18 Conclusions 276 25 ENERGY USE OF HEEP HOUSES COMPARED TO ALF3 278 25.1 Modelling 278 25.2 Selection criteria 278 25.3 ALF3 heating energy estimates 278 25.4 Heating temperature 281 25.5 Modelling issues 284 25.6 HEEP heating energy estimates 290 25.7 Comparison of energy use 291 25.8 Conclusions 296 26 REFERENCES 297 26.1 HEEP reports 297 26.2 HEEP BUILD articles 298 26.3 HEEP conference papers 298 26.4 HEEP Journal Papers 300 26.5 Other HEEP references 300 26.6 References 301 APPENDIX 1: TABLE OF STANDBY POWER AND ENERGY 310 APPENDIX 2: ENERGY CONSUMPTION TABLES 311 APPENDIX 3: ESTIMATES OF PRECISION IN MULTI-STAGE SURVEYS 312 APPENDIX 4: SAMPLING VARIANCE OF THE SURVEY ESTIMATOR 314 APPENDIX 5: EXAMPLE OF BIAS ARISING THROUGH FAILURE TO TAKE ACCOUNT OF VARYING PROBABILITIES OF SELECTION WITHIN HOUSES 318 APPENDIX 6: HISTORICAL REVIEW OF HOT WATER 319 Until piped water 322 Beginnings of piped hot water 325 History of electric hot water 326 History of gas hot water 329 APPENDIX 7: CENSUS DHW QUESTIONS 333 APPENDIX 8: INTERNATIONAL REVIEW OF SHOWER WATER FLOW RATES 334 New Zealand 334 America 334 Australia 335 United Kingdom 336 APPENDIX 9: PENSIONERS HOT WATER USE 337 Hot water energy demand 337 Standing loss determined by tap temperatures 338 Conclusions 339 APPENDIX 10: DHW STANDING LOSSES CALCULATION 340 Initial standing loss estimation methods 340 APPENDIX 11: DHW WET-BACK (SUPPLEMENTARY) WATER HEATING 347 Introduction 347 Calibration of wet-back systems 347 [Figures and illustrations] Figure 1: Map of New Zealand showing HEEP monitoring locations 2 Figure 2: A power station was hiding in the wood shed 3 Figure 3: Theme illustrations from the HEEP Year 10 celebration 4 Figure 4: Electricity use per household 1946-2005 8 Figure 5: Electricity uses 1971/72 8,400 kWh pa 9 Figure 6: Electricity uses HEEP 7,240 kWh pa 9 Figure 7: Energy use distribution – all fuels 10 Figure 8: Energy use distribution – electricity 12 Figure 9: Energy use distribution – gas (natural gas & large bottle LPG) 12 Figure 10: Energy use distribution – LPG (small bottles) 12 Figure 11: Energy use distribution – Solid fuel 12 Figure 12: Regional patterns of energy end-uses 13 Figure 13: Total energy use by fuel type 15 Figure 14: Total energy use by end-use 15 Figure 15: Space heating gross energy by fuel 16 Figure 16: Space heating delivered energy by fuel 16 Figure 17: Energy use by end-use and month 17 Figure 18: Electric appliances 20 Figure 19: Average monthly lighting power – all NZ 21 Figure 20: Fuels all end-uses (Dec yr 2004) 22 Figure 21: Fuels all end-uses (Sept yr 2005) 22 Figure 22: Participation rate of households taking part in HEEP 25 Figure 23: Regional participation rate by urban level 26 Figure 24: Schematic of HEEP data processing 33 Figure 25: A section of a prepro file 33 Figure 26: Sample EDA plots for two temperature sensors 36 Figure 27: HEERA modelling framework 55 Figure 28: HEERA flow diagram with representative tables, algorithms and forms 55 Figure 29: Contribution of new dwellings to the stock of dwellings 60 Figure 30: Net dwelling stock growth over the period 1850 to 2070 64 Figure 31: Building consents (1974 to 2003) compared to vintage stock model 64 Figure 32: New dwelling survival function 65 Figure 33: Probability of new dwelling stock retirement function 65 Figure 34: National dwelling stock by insulation level 68 Figure 35: Mean winter evening living room and ambient temperature by Regional Council 71 Figure 36: Mean winter night time bedroom temperature by Regional Council 72 Figure 37: Distribution of winter evening living room temperatures 72 Figure 38: Living room daytime heating by region and weekday/weekend 74 Figure 39: Heating index by region 74 Figure 40: Bedroom overnight heating by region and weekday/weekend 74 Figure 41: Living room 24 hour heating by region 75 Figure 42: Reported heating season start and finish 77 Figure 43: Length of reported heating season 77 Figure 44: Example – LPG heater use 79 Figure 45: Example – solid fuel use 79 Figure 46: Non-hot water electricity use for one house 80 Figure 47: Months of heating – start and finish 81 Figure 48: Length of heating season 81 Figure 49: External temperature and energy use during heating season 82 Figure 50: Average external temperature for heating season 83 Figure 51: External temperatures of heating start and finish months 83 Figure 52: Living room evening temperature by location and most used heating fuel 85 Figure 53: Winter evening living room temperatures by year built 86 Figure 54: Regional living room temperature differences by insulation requirements 87 Figure 55: Regional bedroom temperature differences by insulation requirements 88 Figure 56: Relationship between temperature difference from the high and low loggers and the difference between outside and inside (linear fit line) 90 Figure 57: Mean living room temperatures 92 Figure 58: Time spent at given temperature ranges 93 Figure 59: Living and bedroom temperature distribution for morning and day 94 Figure 60: Time of maximum living room temperature by Regional Council 95 Figure 61: Maximum living room temperature by Regional Council 96 Figure 62: Mean living room daytime temperatures by Regional Council 97 Figure 63: Summer temperatures by house age 98 Figure 64: Mean living room temperature by airtightness 100 Figure 65: Glazing to wall area ratio by decade house built 100 Figure 66: Solar glazing ratio vs Auckland living room temperatures 101 Figure 67: Palmerston North House 103 Figure 68: Measured parameters 104 Figure 69: Average daily profile 105 Figure 70 Vertical temperature stratification, 1999 (living room south-east corner) 106 Figure 71: Vertical temperature profile, 2000 (living room south-east corner) 107 Figure 72 Hamilton pensioner family room evening temperatures 110 Figure 73 Hamilton non-pensioner family room evening temperatures 110 Figure 74: HEEP and 2001 Census and 2006 Household Composition 113 Figure 75: Age of youngest HEEP household member 114 Figure 76: Equivalised HEEP household income by youngest household member 115 Figure 77: Total fuel use by age of youngest household member HEEP households 120 Figure 78: Winter evening living room average temperature distribution 124 Figure 79: Household composition – HEEP & 2001 Census 127 Figure 80: Age of youngest household member – all & Māori HEEP households 128 Figure 81: Equivalised household income – all & Māori HEEP households 129 Figure 82: Winter evening living room temp – all & Māori HEEP households 130 Figure 83: Total gross annualised energy use for all & Māori HEEP households 131 Figure 84: Total gross annualised heating energy use for all & Māori HEEP households 132 Figure 85: Energy Use Groups vs Dwelling Size 151 Figure 86: Test calibration of gas heated house – House 1 156 Figure 87: Solid fuel calibration graphs (House 2) 157 Figure 88: Equation 15 heat output 159 Figure 89: HEEP estimates and Equation 15 159 Figure 90: LPG heaters per household in city and small town/rural areas 163 Figure 91: Gross energy output for each setting for radiant non-thermostat LPG heaters 165 Figure 92: LPG setting determination for one heater 165 Figure 93:LPG heater use by time of day & day of year (Houses 2 & 4) 168 Figure 94: LPG heater use by time of day & day of year (Houses 1 & 5) 169 Figure 95: Histogram of hours of use LPG heaters (winter months) 171 Figure 96: Histogram of the energy use for LPG heaters (winter months) 171 Figure 97: Proportion of the time spent in the primary settings for LPG heater 171 Figure 98: Expected gas consumption for the 'on' setting for each LPG heater 171 Figure 99: Energy used by each setting for heaters with winter usage 172 Figure 100: Time in each setting for heaters with winter usage 172 Figure 101: Cumulative plot of the energy used by each LPG heater 172 Figure 102: Wintertime LPG heater energy use (in kWh per week) for a number of areas around New Zealand 173 Figure 103: Total house heat loss for pre- and post-1978 houses 176 Figure 104: Heat loss per m² for pre- and post-1978 houses 176 Figure 105: Fitted model plots 184 Figure 106: STEM model results 186 Figure 107: Long-term stock levels of home entertainment appliances 193 Figure 108 Fridge power use histogram 197 Figure 109: Breakdown of standby energy per house by appliance group 200 Figure 110: 10 minute time series of refrigeration appliance power 205 Figure 111: Faulty freezer – 10 minute time series 206 Figure 112: Fridge freezer 10 min time series – cycles <20 min but not faulty 207 Figure 113: Energy use of new frost-free fridge freezers 1980-2006 212 Figure 114: Power factors for monitored houses - Hamilton, Wanganui and Wellington 214 Figure 115: Load curves for different HEEP locations 214 Figure 116: Household daily average real and reactive power and power factor 217 Figure 117: Histograms of the 10 minute power factors by household 217 Figure 118: Mean real and reactive components for each household 218 Figure 119: Real vs reactive power by household 218 Figure 120: House 1 summer day – real & reactive power, power factor 219 Figure 121: House 6 summer day – real & reactive power, power factor 219 Figure 122: Average daily profiles by house – real and reactive power, power factor 220 Figure 123: Examples of hot water cylinders 223 Figure 124: Residential use of storage electric hot water systems 225 Figure 125: Selected nations - electric hot water cylinders by capacity 227 Figure 126: DHW Fuels 228 Figure 127: Variation in proportions of energy end-uses 229 Figure 128: Variation in energy end-uses 229 Figure 129: DHW Energy use distribution – all fuels 230 Figure 130: DHW electricity distribution 232 Figure 131: DHW gas distribution 232 Figure 132: DHW Wetback distribution 232 Figure 133: Average DHW energy profiles 232 Figure 134: Monthly hot water energy profiles 232 Figure 135: National Hot Water Energy Use by Month 233 Figure 136: DHW Energy use by month 233 Figure 137: DHW Energy Use by Month for Houses with that fuel 234 Figure 138: Changing estimates of NZ residential energy end-uses 235 Figure 139: Energy consumption and standing losses by system type 238 Figure 140: Hot water systems – by type and houses 242 Figure 141: Cylinder volumes 245 Figure 142: Cylinder size by region 246 Figure 143: Cylinder size by age 246 Figure 144: NZ Sales by capacity of electric DHW cylinders 2004/5 247 Figure 145: System pressure by region 248 Figure 146: Pressure by house decades 248 Figure 147: Pressure by cylinder decades 248 Figure 148: System age by location 250 Figure 149: 135 and 180 litre cylinders by decade of manufacture 251 Figure 150: Cylinder manufacture compared to house construction decade 251 Figure 151:Total hot water volume vs floor area 253 Figure 152: Total hot water volume vs number of occupants 253 Figure 153: Single electric DHW systems – litres per person 253 Figure 154: Use of baths and showers 1971/72 255 Figure 155: Use of baths and showers HEEP 255 Figure 156: Household DHW volume 1971/72 256 Figure 157: Household DHW volume HEEP 256 Figure 158: Self-reported shower duration – histogram 257 Figure 159: Tap temperature by system type 261 Figure 160: Distribution of hot water tap temperature by electric cylinder volume 262 Figure 161: Variation between thermostat setting & delivered water temperature 264 Figure 162: Adult skin (full thickness) epidermal burn time 266 Figure 163: Hot water temperature vs occupant average age 267 Figure 164: Thermostat setting distribution 267 Figure 165: Tap temperature distribution 267 Figure 166: Thermostat setting vs tap hot water temperature 268 Figure 167: Negawatt cylinder wrap 270 Figure 168: Examples of electric hot water cylinder wraps 275 Figure 169: ALF3 screen image 279 Figure 170: Daily profile of inside temperatures and energy use – weekend 281 Figure 171: Daily profile of inside temperatures and energy use – weekday 281 Figure 172: Winter temperature profiles for Christchurch HEEP houses 282 Figure 173: HEEP sample mean average winter evening temperatures 283 Figure 174: Histogram of living room evening temperatures in selected sample 284 Figure 175: Cumulative frequency of living room temperatures in selected sample 284 Figure 176: Wind exposure classes 287 Figure 177: Percentage versus modelled heated zone methods 289 Figure 178: Average living room temperatures during heating times 292 Figure 179: ALF3 vs reality – 20% lines 293 Figure 180: ALF3 vs reality – 2000 kWh lines 293 Figure 181: Average house temperatures during measured heating times 294 Figure 182: ALF3 vs reality – 20% lines 295 Figure 183: ALF3 vs reality – 2000 kWh lines 295 Figure 184: NZ Census 1945-1996 Domestic Hot Water by fuel type 319 Figure 185: NZ Census 1945-1996 % Dwellings with no DHW 319 Figure 186: NZ Census 1976-1996 Dwellings with only one DHW fuel 320 Figure 187: 1981 Census DHW Fuels 321 Figure 188: 1996 Census DHW Fuels 321 Figure 189: Changes in reported DHW fuel by region 321 Figure 190: First Class Hotel 1899 322 Figure 191: 1930s Laundry Copper 324 Figure 192: Chip heater 324 Figure 193: Push-through water heater 324 Figure 194: Low pressure household hot water system (1923) 325 Figure 195: “An Improved Electrical Water Heater” (1923) NZ Patent 51131 327 Figure 196: “Domestic Boiler System” (1926) US Patent 1,612,270 327 Figure 197: 1888 Lighting Fuel Cost Comparison 329 Figure 198: 1930s ‘Mercer’ Gas Storage Water Heater 331 Figure 199: 1930s ‘Champion’ Gas Cooker, Water heater & rubbish destructor59 331 Figure 200: Standing losses as function of tap temperatures 338 Figure 201: Average daily hot water energy use 340 Figure 202: Leaking cylinder - only turns off during ripple control 342 Figure 203: Cylinder that recharges occasionally 344 Figure 204: Cylinder that rarely turns off 344 Figure 205: Night-rate hot water cylinder 345 Figure 206: Example of a vacancy period 346 Figure 207: Example of a vacancy period for a ‘Night rate’ hot water system 346 Figure 208: Solid fuel burner output vs rate of change of cylinder temperature 347 Figure 209: Solid fuel burner output vs rate of change of cylinder temperature 348 Figure 210: Combined electric and wet-back water heating energy 349 [Tables] Table 1: Location, count and year monitored for HEEP houses 2 Table 2: Fuel use – top and bottom 20% 11 Table 3: Energy end-use by fuel for houses with that end-use 13 Table 4: Total annual energy consumption – all fuels 14 Table 5: Total annual energy consumption per person – all fuels 14 Table 6: Total annual energy consumption – electricity only 14 Table 7: Total annual energy consumption per person – electricity only 15 Table 8: Appliance groups 18 Table 9: Average appliance electricity consumption per household 19 Table 10: Average electricity consumption per appliance 19 Table 11: Average appliance category proportion of electricity 20 Table 12: Lighting power by region 21 Table 13: Participation rate 25 Table 14: Participation rate of households asked to participate in the HEEP study 26 Table 15: What did HEEP record and measure? 28 Table 16: Appliance database 29 Table 17: HEEP people 30 Table 18: Estimated distance travelled by HEEP download staff 30 Table 19: Monitoring equipment 31 Table 20: Logger electrical energy measurement units 34 Table 21: Summary of missing data by circuit 37 Table 22: Summary of missing data by House 37 Table 23: Missing data by year of monitoring 37 Table 24: Missing data - Regional Council 37 Table 25: Missing data - SAMs versus circuit monitoring 38 Table 26: Missing data - Tinytag versus BRANZ temperature loggers 38 Table 27: Missing data – TML 38 Table 28: Circuits missing 38 Table 29: The most common reasons for missing data 39 Table 30: HEERA 16 regions – Regional Councils and Territorial Authorities 59 Table 31: Basic dwelling types for categorising New Zealand dwelling stock 66 Table 32: Extended dwelling types used for categorising the NZ dwelling stock 67 Table 33: HEEP and 1971 descriptive temperatures by region 70 Table 34: Mean temperatures: living room, bedroom and ambient 73 Table 35: Reported evening, all day and no heating by region 75 Table 36: Percentage of houses on various heating schedules 76 Table 37: Pre- and post-1978 heating schedule 76 Table 38: Reported heating season 77 Table 39: Average heating season by region (from north to south) 78 Table 40: Heating start and end month by region 81 Table 41: External temperatures over heating season 82 Table 42: Winter living room evening temperatures by heater type 84 Table 43: Living room winter evening temperature distribution 84 Table 44: Winter temperatures by insulation level 86 Table 45: Regional living room temperatures by insulation requirements 87 Table 46: Temperature difference between upper & lower logger by regional council 89 Table 47: Most used heater type and temperature difference 89 Table 48: Mean temperature during time periods 93 Table 49: Temperatures during afternoon solar gains and evening heating 107 Table 50: Average monthly living room evening temperatures in Hamilton houses (°C) 109 Table 51: Bedroom overnight temperatures in Hamilton houses (°C) 109 Table 52: Income, living room temperature and energy use descriptive statistics 117 Table 53: Correlations equivalised income and energy use variables 117 Table 54: Paired model summaries equivalised income and energy variables 118 Table 55: Household size, living room temperatures and energy use statistics 118 Table 56: Correlations equivalised income and energy use variables 119 Table 57: Paired model summaries household size, occupancy and energy variables 119 Table 58: Frequency table of the life stage variable 121 Table 59: Correlations life stage and energy use variables 121 Table 60: Paired model summaries for life stage and energy variables 121 Table 61: Multiple regression analysis for social dynamics variables and energy use 122 Table 62: HEEP equivalised income quintiles 124 Table 63: Equivalised income by at-risk mean temperatures 124 Table 64: Socio-demographic variables and winter evening living room at-risk (<16ºC) mean temperature 125 Table 65: HES average weekly expenditure by income group of household 125 Table 66: Equivalised income quintiles by winter energy expenditure – HEEP households 126 Table 67: Number of bedrooms for Māori & all HEEP households 129 Table 68: Age of house for Māori & all HEEP households 129 Table 69: Roofing insulation status of house for Māori & all HEEP households 130 Table 70: Winter evening living room temperatures for all & Māori HEEP households 131 Table 71: Winter evening living room temp by fuel for all & Māori HEEP households 131 Table 72: Main heating fuel – 1961 to 1971 Censuses & HEEP 134 Table 73: Heating fuels – 1971/72 Electricity Survey, Censuses & HEEP 134 Table 74: Availability of solid fuel appliances in HEEP households 134 Table 75: Solid fuel appliance types in HEEP households (observed data) 135 Table 76: Availability of solid fuel appliances by location 135 Table 77: Availability of solid fuel appliances by climate zone 135 Table 78: Availability of solid fuel appliances by urban/rural area 136 Table 79: Availability of solid fuel appliances by age of house 136 Table 80: Availability of solid fuel appliances by size of house 136 Table 81: Availability of solid fuel appliances by life stage 136 Table 82: Solid fuel appliance type by use in HEEP households (observed data) 137 Table 83: Use of solid fuel appliances by mix of heating fuels for HEEP households with a solid fuel appliance 137 Table 84: House areas heated by solid fuel appliances for HEEP households using a solid fuel appliance (self-reported data) 138 Table 85: Winter evening living room temperatures by heating fuel type for most used heating appliances 138 Table 86: Winter evening living room temperatures by available solid fuel appliance type for households using solid fuel 138 Table 87: Gas Hot Water Heating, Location and Income Characteristics 142 Table 88: Gas Hot Water Heating, Household Size, Composition, Tenure and Life Stage Characteristics 143 Table 89: Hot water cylinder characteristics by type of hot water heating 144 Table 90: Annualised Gross Energy Use and Annualised Gross Energy Use for Hot Water144 Table 91: Average Summer and Winter Fuel Bills for all energy use 145 Table 92: Key Water Use Patterns 146 Table 93: Number of Showers by Household Size by Type of Hot Water Heating 146 Table 94: Bedrooms and Rooms in Private Occupied Dwellings – 2006 Census 148 Table 95: The Size of HEEP Dwellings 149 Table 96: Estimated Typical Monthly Winter Energy Costs by the Size of HEEP Dwellings 150 Table 97: Estimated Typical Monthly Winter Energy Costs by Dwelling and Household Size150 Table 98: Total Energy Annual Use by the Size of HEEP Dwellings 150 Table 99: Total Annual Energy Consumption by HEEP Dwelling and Household Size 152 Table 100: Calibration slopes 156 Table 101: Assumed efficiencies of solid fuel burners 158 Table 102: Annual gross energy input by appliance type 160 Table 103: Variation of gross annual solid fuel energy consumption by location 160 Table 104: HES Household Heating Appliances 162 Table 105: Ownership of LPG heaters in the HEEP sample 163 Table 106: Gross energy output for each heater setting of the non-thermostatically controlled heaters 164 Table 107: Setting assignment errors for one heater 166 Table 108: Usage of LPG heaters from the processed HEEP LPG sample 170 Table 109: Mean LPG heater duration and energy consumption 170 Table 110: Mean energy consumptions for each setting 172 Table 111: Ownership of LPG heater and dehumidifier 173 Table 112: Heat losses for pre-and post-1978 HEEP houses 176 Table 113: Average winter temperatures by heating type 176 Table 114: Comparison of winter temperatures and Heat Index 177 Table 115: Comparison of space heating energy 177 Table 116: Mainly electrically heated houses space heating energy and temperatures 179 Table 117: Summary of model results 181 Table 118: Comparison of STEM and ALF U-value and thermal mass estimates 187 Table 119: Summary of the appliance ownership models 192 Table 120: Summary of the appliance energy models 192 Table 121 Top five appliances by standby power and energy 199 Table 122 Standby energy per house by appliance group 200 Table 123: Heated towel rail average power use 201 Table 124: New Zealand standby and baseload 202 Table 125: Breakdown of faulty appliances by type 208 Table 126: Breakdown of refrigeration appliances by decade 208 Table 127: Performance of algorithm at threshold of 07 209 Table 128: Performance of algorithm at threshold of 09 210 Table 129: Ownership of refrigeration appliances 216 Table 130: Average fraction of reactive energy from constant load 220 Table 131: Hot water cylinder characteristics by type 222 Table 132 Regional annual hot water energy use by fuel (kWh/house with fuel) 222 Table 133: Building Regulations 1992 Clause G12 – Objective 223 Table 134: Building Regulations 1992 Clause G12 – Performance (hot water) 224 Table 135: NZBC G12/AS1 – Water Temperature & Control (3rd Edition 2006) 224 Table 136: DHW fuels – international comparison 225 Table 137: Average DHW energy use by capacity 228 Table 138: Energy & proportion of main end-uses 230 Table 139: DHW Fuel use – top and bottom 20% of houses 231 Table 140: Hot water energy use by number of occupants 235 Table 141: Electric hot water cylinder standards 236 Table 142: Electric storage cylinder standing losses by size and grade 237 Table 143: Total energy consumption and standing losses by HEEP system type 237 Table 144: Household hot water energy use by system type 238 Table 145: Comparison gas & non-gas water heater households 239 Table 146: Regression model for hot water energy use 239 Table 147: Life stage by water heating fuel 240 Table 148: Linear model application – non-gas and gas water heating 241 Table 149: HEEP hot water systems 241 Table 150: Hot water adequacy by fuel type for randomly selected houses 242 Table 151: Hot water adequacy by system pressure 243 Table 152: Wetback use by region 244 Table 153: Cylinder volume range 245 Table 154: Hot water systems by fuel source and cylinder volume 245 Table 155: System pressure by fuel type 248 Table 156: HEEP random electric and gas cylinder descriptive statistics 250 Table 157: House and cylinder age comparison 252 Table 158: Life expectancies of cylinder types 252 Table 159: Hot water requirements for baths and showers 254 Table 160: Self reported bathing times 257 Table 161: Self reported shower duration by time of day per house 257 Table 162: Shower flow ratings 258 Table 163: HEEP shower flow by water pressure and temperature 259 Table 164: Maximum & minimum water flows 259 Table 165: HEEP Shower warm flow rates by WMCS rating 259 Table 166: Effect on average flows from retrofitting ‘low flow’ shower heads 260 Table 167: Auckland water costs (1 Sept 2006) 260 Table 168: High tap temperatures by system type 261 Table 169: HEEP 135 and 180 litre cylinder statistics 262 Table 170: Count of thermostat setting vs tap hot water temperature 268 Table 171: Tap Temperature and use of tempering valve 269 Table 172: Count of cylinder grade by house decade of construction 272 Table 173: Cylinder wrap cost benefit by cylinder grade 273 Table 174: Some alternative measures for D grade 180 litre retrofit 274 Table 175: Methods to reduce hot water emissions 275 Table 176: Length of Heating season 280 Table 177: ALF3 heating schedules 281 Table 178: Mean heating times on winter evenings 282 Table 179: Average heating temperatures in selected houses 283 Table 180: Wall and roof construction 285 Table 181: Construction R-value with no insulation 285 Table 182: Air leakage rates 287 Table 183: Climate locations 288 Table 184: Weighting of spaces for heating 293 Table 185: Standby power and energy for all measured appliances 310 Table 186: Average annual total energy use per house by fuel 311 Table 187: Average annual hot water energy use per house by fuel 311 Table 188: Average annual space heating energy use per house by fuel 311 Table 189: Average annual energy use per house for selected end-uses 311 Table 190: Christchurch Gas Company - Gas cost £ per 1,000 ft³ 330 Table 191: Average gas by end-use: projected 1976 use & HEEP use 332 Table 192: NZ Censuses historical summary 1945-2001 – hot water questions 333 Table 193: NZ Censuses 1945-1996 – text of hot water questions 333 Table 194: North America – shower water use 335 Table 195: Australia – shower water usage 335 Table 196: Perth – shower water use 335 Table 197: Hot water energy comparison 337 Table 198: Hot water systems – comparison of properties 337 Table 199: Wetback heat output percentages 350 Full story including links for full report download (BRANZ) and online viewing. |