NZEB OFFICE BUILDING INCLUDING RENEWABLE ENERGY RATIO CALCULATION
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WHAT IS EPC/ CPC/ RER
It is an ASSET assessment not an operational assessment
EPC – Energy Performance Coefficient MPEPC 1.0
Primary Energy Consumption of Proposed Building
Primary Energy of Reference Building based on Interim Spec
CPC – Carbon Performance Coefficient MPCPC 1.15
Carbon Emissions of Proposed Building
Carbon Emissions of Reference Building based on Interim Spec
Renewable Energy Ratio: RER > 20%
Renewable Primary Energy
Total Primary Energy including Renewable
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CONTENTS
CREATING THE
REFERENCE BUILDING
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GUIDANCE
PAGE 4
PROJECT DATABASE
PAGE 5
GEOMETRY
PAGE 6
GEOMETRY
PAGE 7
HVAC – CENTRAL HEATING WITH RADIATORS
PAGE 8
HVAC – AIR CONDITIONING
PAGE 9
HVAC – AIR CONDITIONING
PAGE 10
HVAC – AIR CONDITIONING
PAGE 11
LIGHTING
PAGE 12
LIGHTING
PAGE 13
LIGHTING CONTROLS
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CONTENTS
LESSON LANE
PAGE 15
PROJECTS
Lesson Lane
• 6500m2 7 storey plus basement Office Block in City Centre
• Naturally Ventilated Offices - fresh air mechanically supplied with Heat
Recovery
• FCU in Meeting Rooms
• Split System in Comms Rooms
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LESSON LANE – INTERIM SPECIFICATION
Element Interim
Specification
Fabric
Backstop
Lesson Lane
Fabric
Roof U Value (W/(m2K)) 0.15 0.21 0.1
Wall U Value (W/(m2K)) 0.18 0.21
0.35 for insulated spandrel panel
0.1 for all other heat loss walls
Floor U Value (W/(m2K)) 0.15 0.21 0.1 for all heat loss floor
Thermal Bridging ACD ACD ACD Window U Value (W/(m2K)) 1.4 1.4 0.8
% glass of Exposed Façade 40% 60% 60%
G-Value (%) 0.4 0.35 0.35
Light Transmittance (%) 0.71 0.55 0.55 Air Permeability (m3/(m2h) 3 3 1
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LESSON LANE – INTERIM SPECIFICATION
Element Interim
Specification
Fabric
Backstop
Lesson Lane
Lighting
Lighting 65 Lumen/circuit watt
with MF 0.8 LED
(1.6 w/m2/100 lux) LED
(1.6 w/m2/100 lux)
Daylight Control Switching Dimming Dimming
Occupancy Control Auto On/ Dim Auto On/ Off Auto On/ Off
HVAC
Heating 91% 92% 92% Variable speed control of fans and pumps Yes Yes Yes
M&T - M&T on HVAC and
Lighting M&T on HVAC and
Lighting
Cooling (air-conditioned) (SEER/SSEER)
4.5 SEER/ 3.6 SSEER 2.7 SSEER mixed mode
3.5 SEER/ 2.39 SSEER Mixed Mode cooling FCU
- Meeting rooms 3.5 SEER/ 2.62 SSEER
Cooling Split System in Comms Rm
3.5 SEER/ 2.39 SSEER Mixed Mode cooling FCU -
Meeting rooms 3.5 SEER/ 2.62 SSEER
Cooling Split System in Comms Rm
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LESSON LANE – INTERIM SPECIFICATION
Element Interim
Specification
Fabric
Backstop
Lesson Lane
Ventilation Demand Controlled
S&E Fresh Air only to Offices and Meeting rooms
with heat recovery S&E to WCs and photocopy
with heat recovery Extract from tea station
S&E Fresh Air only to Offices and Meeting rooms with
heat recovery S&E to WCs and photocopy
with heat recovery Extract from tea station
Central Ventilation SFP (W/(l/s)) 1.8 1.5 1.5
Heat Recovery - 80% 80%
DHW
Hot Water Heater 91% 92% Natural Gas 92% Natural Gas
DHW Tank 2000 litres 2000 litres 2000 litres
Insulation on Tank 75mm 75mm 75mm Secondary Circulation Losses (W/m) 7 7 7
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PRIMARY ENERGY
Heating, 38.1, 29%
Cooling, 3.5, 3%
Auxiliary, 15.4,
12%
Lighting, 50.9,
39%
Hot Water, 22.5, 17%
INTERIM SPEC
Heating, 29.3,
31%
Cooling, 5.1,
5% Auxilia
ry, 13.8, 15%
Lighting, 28.8,
31%
Hot Water, 17.1, 18%
FABRIC BACKSTOP
Heating, 10.8, 14%
Cooling, 5.6, 7%
Auxiliary, 13.8,
18%
Lighting, 28.7,
38%
Hot Water, 17.1, 23%
CURRENT DESIGN
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INTERIM NZEB SPECIFICATION TOOL
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INTERIM NZEB SPECIFICATION TOOL
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INTERIM NZEB SPECIFICATION TOOL
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PHOTOVOLTAIC
PAGE 24
PHOTOVOLTAIC
Interim
Specification
Fabric Backstop Lesson Lane
Photovoltaic 623m2 500m2 385m2
kW 94 75 57.7
Photovoltaic Issues
• Roof Space Requirement
Roof Area approx 784m2
Allowing for overshading – 392m2
• Is peak load exceeding base load
within building
• Would you need to export electricity,
associated costs
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SOLAR PANELS
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SOLAR PANELS
Interim
Specification
Fabric Backstop Lesson Lane
Solar Panels 500m2 500m2 500m2
Solar Panel Issues
• Limited by requirement for hot
water
• Limited by roof space
• Additional storage volume
required
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BIOMASS
PAGE 28
BIOMASS
Interim
Specification
Fabric Backstop Lesson Lane
% of Htg & DHW 55% 42% 55%
Estimated kW 448kW 351kW 233kW
kWh 191,802 112,306 88,360
Biomass Issues
• Constant Thermal Base Load
• Adequate Space for Storage
• Access for delivery of fuel
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CHP
PAGE 30
CHP
Interim
Specification
Fabric Backstop Lesson Lane
% of Htg & DHW 100% 100% 100%
CHP Issues
• Is there a constant thermal load
and electrical load, 100% of
thermal load is not feasible
• Location of plant
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BIOGAS CHP
Interim
Specification
Fabric Backstop Lesson Lane
% of Htg & DHW 50% 20% 25%
CHP Issues
• Is there a constant thermal load
and electrical load, 15/20% of
thermal load is feasible
• Thermal Efficiency is reduced
• Location of plant
• Security of fuel supply?
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HEAT PUMP
PAGE 33
HEAT PUMP
Interim
Specification
Fabric Backstop Lesson Lane
% of Htg 100% 100% 100%
% of DHW 0% 0% 0%
Heat Pump Issues
• Is it feasible to use low
temperature installation – Use of
FCU/ AHU?
• Space requirements for plant
• GSHP v ASHP
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HEAT PUMP 2
Interim
Specification
Fabric Backstop Lesson Lane
% of Htg - - 100%
% of DHW - - 100%
Heat Pump Issues
• Is it feasible to use low
temperature installation – Use of
FCU/ AHU
• Space requirements for plant
• GSHP v ASHP
• Based on COP 250 for DHW
• Hot Water temperature
requirement for DHW to avoid
Legionella
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HEAT PUMP & PV
Interim
Specification
Fabric Backstop Lesson Lane
% of Htg - - 100%
% of DHW - - 0%
Photovoltaic - - 200m2
Heat Pump Issues
• Is it feasible to use low
temperature installation – Use of
FCU/ AHU
• Space requirements for plant
• GSHP v ASHP
• Space requirement for PV
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LESSON LANE – RER SUMMARY
Interim
Specification
Fabric
Backstop
Lesson Lane
Photovoltaic
Solar Panel
Biomass
CHP
Biogas CHP
Heat Pump Htg Only
Heat Pump Htg & DHW - -
Heat Pump Htg & PV - -
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CONTENTS
LESSON LANE – AIR
CONDITIONED OFFICE
PAGE 38
LESSON LANE – TYPE OF SYSTEM?
NATURALLY
VENTILATED
FAN COIL UNIT ACTIVE CHILLED
BEAM
Photovoltaic 385m2 800m2 550m2
EPC 0.58 0.85 0.62
CPC 0.59 0.88 0.64
RER 0.2 0.21 0.21
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ACHIEVING RENEWABLE WITHIN AC OFFICE?
ACTIVE CHILLED
BEAM
ACTIVE
CHILLED BEAM
SPLIT
Renewable 550m2
Photovoltaic
350m2 Photovoltaic
with
Heat Pump
providing Heating
350m2 Photovoltaic
with
Heat Pump providing
Heating
EPC 0.62 0.64 0.61
CPC 0.64 0.66 0.63
RER 0.21 0.21 0.21