green hvac systems - airah · 16 passive chilled beams 2700 150 800 energy efficiency: 5* - 5*+20%...
TRANSCRIPT
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Outline – Green HVAC Back to basics
Green HVAC-what and why? System examples Importance of green HVAC in relation to Green
Star
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HVAC - Heating Ventilation & Air Conditioning
This can be by a mechanical system
Or by passive natural
ventilation
…or a combination
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What does Green HVAC mean?
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HVAC and energy consumption
Approximately 40% of office energy consumption is from HVAC
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What does Green HVAC mean?
Green buildings does not start with Green HVAC - Impacted by low energy design
8 Consider building form, orientation and fabric
Exposed thermal mass
Tall space - buoyancy driven ventilation
Automatic windows - night cooling
External shading
9 Minimise loads
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Why is solar control important?
Typical Heat Gains:
Lighting = 10W/m2
People = 15W/m2
Equipment =15W/m2
Solar Gain is 65% of cooling load!!!
Perimeter Solar Gain =80W/m2
80% GlazingSHGC = 0.25U Value = 2.8 W/m2.kNorth Facing
11 Consider location and climate
Type of HVAC Systems
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HVAC - Heating Ventilation & Air Conditioning
This can be by a mechanical system
Or by passive natural
ventilation
…or a combination
14 Natural ventilation
15 Mixed mode ventilation –ASB North Warf
16 Passive Chilled Beams
2700
150
800
Energy efficiency: 5* - 5*+20% NABERS achievable
Comfort: Good. High supply temperature and low velocities.
Health: Increased outside air rates can assist with IEQ
Space: Outside air (or slight increase) only which means smaller riser space and increased NLA
Cost: compared to conventional systems
17 Passive and Active Chilled Beams
2700
250
800
Primary Ventilation Air Passive Chilled Beam Active Chilled Beam
Energy efficiency: 5* - 5*+20% NABERS achievable
Comfort: Good. High supply temperature and low velocities.
Health: Increased outside air rates can assist with IEQ
Space: Smaller riser space – more NLA
Cost: compared to conventional system
18 Displacement Ventilation
2700
150
400
450(Structural Zone)
Energy efficiency: 5* - 5*+20% NABERS achievable
Comfort: Very good. Individual thermal comfort
Health: Very good. High ventilation rates no mixing of contaminants
Space: Larger riser space – reduced NLA
Cost: compared to conventional system
19 Chilled Ceilings and Underfloor Outdoor Air Supply
2700
150
600
200
Energy efficiency: 5* - 5*+20% NABERS achievable
Comfort: Very Good. High thermal comfort because of high radiant component
Health: Very good. High ventilation rates no mixing of contaminants
Space: Smaller riser space compared to UFAD only
Cost: compared to conventional system
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HVAC system types - constaints
Green Star and HVAC systems
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24 Indoor Environment Quality
Points available around• Outside air• Acoustic comfort• Indoor pollutants • Thermal comfort
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= 20 possible points…
…out of a total of 100 points
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Base case is 10% improvement on a reference building which achieves compliance with Section J in NCC
Points awarded for improvement on the reference case in regards to façade performance and estimated greenhouse gas reduction
Points in the Energy category
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Base case is 10% improvement on a reference building which achieves compliance with Section J in NCC
Points awarded for improvement on the reference case in regards to façade performance and estimated greenhouse gas reduction
Points in the Energy category
5 Star NABERS results in approximately 4 points in the energy category
