Non-residential Energy Use –possible & measurementChristchurch Energy Awareness Week

Nigel Isaacs, BRANZ Ltd.nigelisaacs@branz.co.nz

Phone (04) 238 1366

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: www.branz.co.nz

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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 conditioningPool / spa

Restaurant(s)

Poor correlation – but why? Bigger = better operated? = more facilities? Energy use irrelevant to design & operation

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Lighting Efficacy – higher efficacy is better

Source: http://www1.eere.energy.gov/buildings/ssl/efficacy.html See also: Buildings Energy Data Book - http://buildingsdatabook.eren.doe.gov/

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

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