Transcript Is Your Home Warm Enough Talk for Wellington City Eco

Non-residential Energy Use
–possible & measurement
Christchurch Energy Awareness Week
Nigel Isaacs, BRANZ Ltd.
[email protected]
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
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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
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Expenditure:
Energy Use :
Production :
Patterns of Use :
Plant :
$ spent on energy
e.g. kWh, MJ
e.g. tonnes of product
e.g. hours/day, days/week
e.g. serviced last year
Seasonal Energy Comparison
Two Auckland Hotels
Management is a key issue
 Heating or cooling running all year?
Energy per bedroom by hotel size
Lots
Air conditioning
Pool / spa
Restaurant(s)
kWh/bedroom/year
Few
facilities
Little
Small
Number of Bedrooms
North Island
South Island
Poor correlation – but why?
 Bigger = better operated? = more facilities?
 Energy use irrelevant to design & operation
Big
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/
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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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