Non-residential Energy Use –possible & measurement Christchurch Energy Awareness Week Nigel Isaacs, BRANZ Ltd. Phone (04)

Energy – Measuring Success  Why use energy?  Dealing with variation  Day/Night, Weekday/Weekend, Seasons  Different buildings  Are halogen lights energy efficient?  BEES  NZ wide study  Energy & water use in non-residential buildings  Fuels and services they provide  For more information: 2

Why Use Energy In Buildings?  Not just for the pleasure of using energy! To modify the human environment:  Hygrothermal  warm, cool, humidity  Visual  light, glare  Acoustic  speech, noise, warnings  Indoor Air Quality (IAQ)  breathing clean, fresh air  Activity  calculation, drawing, talking, sleeping …

Dealing With Variation  “Normalise”  Bring to a standard condition  Different buildings  One building over time  Look for some consistent factor:  People - kWh/employee  Area - MJ/square metre, kWh/m²  Other – e.g. kWh/claim, kWh/bed  “Pattern” extraction  Look for time (or other) patterns  Day / Season / Year

Energy Use History (MJ/m²/day) Tenant electricity approx 85% lighting

Energy Cost History ($/m²/day) Tenant electricity: 54% energy, 66% $$$ Energy (efficiency) is not the only issue  Relative cost of different fuels for different services

Understanding Energy Use  Differences between building uses and types:  Hours of Use : Day / Night / Weekend  Lights : Controllable / Daylight / Zones  Equipment : ‘Plug loads’ / Computers / Specialist  Key Information  Expenditure: $ spent on energy  Energy Use : e.g. kWh, MJ  Production : e.g. tonnes of product  Patterns of Use : e.g. hours/day, days/week  Plant : e.g. serviced last year

Seasonal Energy Comparison Management is a key issue  Heating or cooling running all year? Two Auckland Hotels

Energy per bedroom by hotel size Few facilities Air conditioning Pool / spa Restaurant(s) Poor correlation – but why?  Bigger = better operated? = more facilities?  Energy use irrelevant to design & operation

10 Lighting Efficacy – higher efficacy is better Source: See also: Buildings Energy Data Book -

Building Energy End-use Study  BEES  Non-residential buildings (offices, shops & mixtures)  Exploring hows, whys, wheres & whens  Energy & water use and services  Random sample of buildings nationwide  Preliminary results by 2011  Telephone Survey  Data on building, business, use  Access to revenue (bill) data  Detailed monitoring  Monitor to understand services e.g. hot or cool air, Office equip., Kitchen, Computer, etc  Case studies on special issues e.g. labelling of circuits  Survey occupants to understand their needs & roles 11