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Our 2020 VisionUpdate on Building Services Design & Sustainability
Presentation by Dr Christopher Marien, Emily Mansfield and Patroula Christopoulou
23rd January 2020
We provide our clients with a truly multi-disciplined professional consultancy service which includes:
About Us
calfordseaden is an award-winning multi-disciplinary consultancy with a trading history of almost 70 years. Our core vision has remained the same since our inception: to be the trusted provider of a high quality and professional service.
Content
• Building Regulations – What’s changing and the impacts (Emily Mansfield)
• SAP Methodology – Key changes (Emily Mansfield)
• Passive House – Basic Principles (Patroula Christopoulou)
• Estimated Construction Costs for Passive House Certification (Patroula Christopoulou)
• Heat Pump Solutions Review (Chris Marien)
• Achieving Zero Carbon (Emily Mansfield)
• Hydrogen Fuel (Chris Marien)
SAP 10 And Part L Updates
SAP Methodology – Key Changes
• Thermal bridging (y-value) default increased to 0.20W/m2K and psi-values increased
• Solar Photovoltaic (PV) array – recognises use of battery storage and diverter
• Community heating distribution pipework losses factor increased to 2 (1.5 if CP1 applied)
• Fuel Tariffs updated – p/kWh of energy used within dwelling
• CO2 emission factors updated – kgCO2/kWh of energy used within dwelling
• Primary energy factors updated – kWh of energy used to deliver fuel / kWh of energy used within dwelling
Updated Fuel Tariffs
Fuel Type SAP 2012 SAP 10.1
Mains Gas 3.48 3.93
Electricity (standard tariff) 13.19 17.56
Electricity Export 13.19 5.30
p/kWh
Price of electricity is shown to increase by 4.37p/kWh compared to current SAP methodology and to be almost five times more expensive than mains gas
0.00
2.00
4.00
6.00
8.00
10.00
12.00
14.00
16.00
18.00
20.00
Mains Gas Electricity
p/k
Wh
Fuel Tariffs
SAP 2012 SAP 10.1
13%
347%
33%
Updated CO2 Emissions
Fuel Type SAP 2012 GLA SAP 10.1
Mains Gas 0.216 0.210 0.210
Electricity 0.519 0.233 0.136
kgCO2/kWh
The CO2 emissions factor proposed for electricity take into account the decarbonisation of the National Electricity Grid and are shown to be lower than mains gas
These figures could potentially change again once Part L consultation is complete
0.000
0.100
0.200
0.300
0.400
0.500
0.600
Mains Gas Electricity
kgC
O2/
kWh
CO2 Emission Factors
SAP 2012 GLA London Plan SAP 10.1
3% 3%
55% 74%
35%
Updated Primary Energy
Fuel Type SAP 2012 SAP 10.1
Mains Gas 1.220 1.130
Electricity 3.070 1.501
kWh/kWh
Primary Energy Factor for mains gas has slightly reduced
Similar to CO2 emissions, the primary energy factor for electricity has significantly reduced. However, it still remains higher than mains gas
0
0.5
1
1.5
2
2.5
3
3.5
Mains Gas Electricity
kWh
/kW
h
Primary Energy Factors
SAP 2012 SAP 10.1
7%
51%
33%
Part L Consultation Issued October 2019Area What’s changed Impact
Criterion 1 Focuses on primary energy as well as CO2 emissions Careful design required for electric heating
Householder Affordability New regulation requirement for heating, hot water and lighting – based on EPC
Direct electric heating may not be affordable – unless improvements made to reduce space heating demand
Summer overheating New regulation? Takes into account pipework losses and water storage losses
Require dynamic simulation? – Already part of GLA requirements
Air pressure testing Part F may require all dwellings to be tested Already common practice by most developers
Electricity CO2 emission factor decreased
Now shown as 0.136kgCO2/kWh – Lower than gas! More improvement measures to be implemented –increased amount of PV array
Electricity primary energy factor decreased
Now shown as 1.501kWh/kWh Moving closer to gas, makes it easier to achieve the primary energy targets
Electricity cost increased Now shown as 17.56p/kWh (based on 5-year average predicted values)
Already becoming more expensive – leading to poor EPC rating
Two options proposed for Notional Dwelling (TER)
Option 1- Improved building fabric (triple glazing), WWHR (20% reduction)Option 2 – Improved technologies (WWHR & PV) and smaller building fabric improvements (31% reduction)
Option 2 government’s preferred option – estimated increase in cost of £4,847 saving households £257/year. It is expected builders will choose less costly ways of meeting targets
Passive House Principles
Definition of Passive House
“A Passivhaus (German Standard) House is a building, in which thermal comfort can be provided solely by heating or cooling of the fresh air flow* which is required for good indoor air quality” Passipedia
*without using recirculation
In Practice:
• A building with space heating requirements designed close to the theoretical minimum
• Using Passive principles to their full extent before active design – i.e. insulation before heating
• With low energy design included in all the services: heating, hot water, lighting and appliances
• Heating doesn’t necessarily have to be achieved through air heating Goldsmith Street, Norwich – Winner of the RIBA Stirling Prize 2019
Principles of Passive House – New Build
Item: Criteria Strategy
Air-tightness 0.6ach @ 50Pa Test rate of approx. 1m3/h.m2
Surface temperature >17oC Triple glazing and thermal bridge free junctions
Summer overheating Must not exceed 25oC for more than 10%
Passive House based on constant internal temperature of 20°C
Ventilation ∼30m3/h.person MVHR
Heating 15kWh/m2/year or 10W/m2 Promotes ‘fabric first’ approach
Primary Energy 135kWh/m2/year UK figure (differs based on location)
Renewable Primary Energy
60kWh/m2/year (Classic)45kWh/m2/year (Plus)35kWh/m2/year (Premium)
Ensure renewable technologies are not used as bolt on to achieve the Primary Energy Target
Co
mf
or
tE
ne
rg
y
Key Elements - Shape & Orientation
• Simple shape – lower form heat loss factor
• Reduce difficult detailing and thermal bridging
• Optimise orientation – Solar gains
Passivhaus Institute / AECB Carbon Lite / GOSOL
The lower the form heat loss factor the better
Key Elements – Building Fabric & Ventilation
+ + +
EXTRACT AIR
EXTRACT AIR
SUPPLY AIR
SUPPLY AIR
INTAKE
EXHAUST
MVHR
BATHROOM
KITCHEN
BEDROOM
LIVING ROOM ∞
Building Regulations Vs Passive House Standards
Building Element Notional Building(Part L1A 2013)
Passive House
U-values (W/m2K):
• Walls 0.18 0.15
• Roofs 0.13 0.15
• Floors 0.13 0.15
• Windows (g-value) 1.40 (0.63) 0.85 (0.50)
• Doors 1.00 1.00
Thermal Bridging (y-value) ACDs 0.05W/mK*
Design Air Permeability Rate (@50Pa) 5m3/hm2 1m3/hm2
Mechanical Ventilation Intermittent extract MVHR (certified)
Passive House Estimated Construction Costs
Passivhaus Trust carried out a study in October 2019 – Passivhaus Construction Costs
Applying best practice extra costs indicates an uplift in costs of approximately 8-11% higher when set against comparable projects - £115/m2 (using Spons UK build cost for terraced housing)
Extra costs estimated at 4% if the quality assurance process of Passive House becomes a standard
Areas shown to have greatest additional costs:
• Wall & roof structures• Use of MVHR – Typical Non-PHI: £1,098, Typical PHI certified: £2,820• Airtightness Testing (more rigorous standard)• Site supervision (approximately £80/m2)
Passive House standards can be used as a driver for on site skill and quality uplift
Heat Pump Solutions Review
1) Hybrid: Heat Network + Gas Boilers + Centralised ASHP
2) Centralised ASHP: Low Temperature Heat Network + Centralised ASHP
3) Two-Stage Communal System: Ambient HN + Centralised ASHP + Individual WSHP
4) Individual ASHP
5) Individual Exhaust Air Heat Pump (two stage MVHR-EAHP)
1. Hybrid: Heat Network + Gas Boilers + Centralised ASHP
Mix Valve 55oC - 70oC
<40oC
80oC
40oCASHP: Min 45oC Max 65oC
<55oC
COP - Coefficient of Performance (i.e. efficiency)
1no. ASHP Unit:- 43kWthermal- 500kg- 760W x 2000L x 1700H- Circa £23k each
Gas Meter
ThermalStore
ThermalStore
ThermalStore
2. Centralised ASHP: Low Temperature Heat Network + Centralised ASHP
Max 55oC
<40oC
COP - Coefficient of Performance (i.e. efficiency)
>50oC
55oC
1no. ASHP Unit:- COP 1.5 - 3- 43kWthermal- 500kg- 760W x 2000L x 1700H- Cost circa £23k each
Design Considerations:- Location (roof / landscape)- Weight- Noise- Visual- Electrical Load / Substation(s)- Low Temp HN ( min/max 55oC)- UFH - Minimise dwelling heat demand
ThermalStore
3. Two-stage Communal System: Ambient HN + Centralised ASHP + Individual WSHP
25oC
15oC
1no. ASHP Unit:- COP 1.5-3- 43kWthermal- 500kg- 760W x 2000L x 1700H- Cost circa £23k each
Design Considerations:- ASHP Location (roof/landscape)- ASHP & WSHP Weight- ASHP & WSHP Noise- ASHP Visual- Electrical Load/Substation(s)- HN Pipework size (increased SV) - Diversity Calculations- UFH - Cost Unknown- No/Limited Market Examples - O&M Market Availability
1no. WSHP Unit:- COP 4
- 4kW & 6kW - 353kg
- 550W x 560L x 2000H- Primary Flow Rate: 0.25l/s- HWS Reheat 2hrs-2.75hrs
- Immersion heater- Noise Rating 35
- Cost: £5-10k?
HWS
WSHP
4. Individual ASHP
Design Considerations:- ASHP Location (roof / landscape / Façade/ Balcony)- ASHP Noise- ASHP Visual- Electrical Load / Substation(s)- HP Pipework Length max 30m - Internal Distribution (Risers & Service Voids)- UFH / Rads
1no. ASHP Unit:- COP 1.5 - 3- 4kW - 12kW - Internal Unit: 650W x 730D x 1800H (130kg)- External Unit: 1085W x 360L x 735H (80kg)- Immersion heater- Noise Rating 35- Cost: £2-4k
Radiator Sizes:
Flow Temp: 70oCOutput: 500w
Height: 500mmWidth: 300mm
Flow Temp: 50oCOutput: 500w
Height: 500mmWidth: 800mm
HWS
5. Individual Exhaust Air Heat Pump (Two Stage MVHR-EAHP)
Design Considerations:- Location (external wall)- Noise- Electrical Load / Substation(s)- Large Ventilation Duct Size (160mm dia) - Warm Air heating (i.e. no UFH / Rads)- Passive House levels of thermal efficiency - Low water use taps and showers.
1no. MVHR-EAHP Unit:- COP: 4-6- Capacity: <2.5kW - Internal Unit: 900W x 610D x 2065H- Duct Connections: 160mm (dia)- HWS Cylinder: 180Ltrs- HWS Reheat: trickle? - Immersion heater: 1.5kW- Noise Rating: ?- Ventilation Rate: upto 300m3/hr- Cost: £9k
Images: Twinn, C (2019). Heat Autonomy Life After District Heating (on route to zero carbon)
Hot Water Mode:
ComparisonSolution Policy
Compliance (LP 35%)
Heat Pump Type
Additional Heat Sources
HIU Required Heat Network Flow / Return
Temps
Heat Network Auxiliary Equipment
Substation Required*
Seasonal use of ASHP
Source of Fuel Heat Metering System
Capital Cost Residents Affordability
Hybrid: HN + Boilers + ASHP
Yes(35-40%)
Centralised ASHP
Centralised gas boilers
Yes 70-55oC / <40oC
Circulator pumps, distribution pipework, pressurisation unit, filtration unit
Less likely Majority of the year where high COP can be maintained
Electricity and gas
Yes Comparable with standard HN+CHP
Potentially lower thancurrent heat networks owing to optimum efficiencies
ASHP Heat Network
Yes(40-60%)
Centralised ASHP
None Yes 55oC / <40oC Circulator pumps, distribution pipework, pressurisation unit, filtration unit
Highly Likely All year Electricity only Yes Higher than standard HN-CHP
Potentially high cost owing to low COP in Winter
ASHP + WSHP (ambient loop)
Yes(50-70%)
Centralised ASHP + WSHP in dwelling
HWS cylinder with Immersion heater
NoWSHP and HWS cylinder
25oC / 15oCHeat topped up in dwelling via WSHP
Circulator pumps, distribution pipework, pressurisation unit, filtration unit
Highly Likely All year Electricity only Yes Very high (cost of communal system + domestic WSHP)
Potentially high cost owing to HWS immersion heater
Individual ASHP
Yes(40-60%)
Individual ASHPInternal & External unit
HWS cylinder with Immersion heater
NoHWS cylinder
n/a n/a Highly Likely All year Electricity only No £2-4k/unit Potentially high cost owing to HWS immersion heater
MVHR-EAHP Yes(60-70%)
EAHPInternal unit
HWS cylinder with Immersion heater
NoHWS cylinder
n/a n/a Highly Likely All year Electricity only No £9k/unit Potentially very high cost owing to HWS immersion heater, limited heat capacity and high air change rate
Achieving Zero Carbon Homes
Energy Hierarchy
Source: Greater London Authority
Carbon Offset Payment currently £60/tonneCO2 over 30 years (£1,800/tonneCO2)
Draft London Plan proposes £95/tonneCO2 over 30 years(£2,850/tonneCO2)
Example House – Improved Fabric + ASHP
SAP 2012
SAP 10
%
42% Wet 0kWp £4,090
£
£%
61% Wet 0kWp £1,836
Example House – Improved Fabric + ASHP + PV + Battery
SAP 2012
SAP 10
%
101% Wet 3.27kWp £0
£
£%
100% Wet 3.27kWp £0
Apartments (54 Units) – Improved Fabric + Community Heating (ASHP + Boilers) + PV SAP 2012
%
40% Wet 27.5kWp £100,203 / £1,856/unit
£
SAP 10
%
52% Wet 27.5kWp £70,575 / £1,307/unit
£
Heating System:SAP 2012 SAP 10
£/year: Improvement: £/year: Improvement:
Main gas boiler 177.94 3.07% 200.95 7.32%
Direct electric 578.72 3.09% 770.45 35.26%
ASHP 300.96 29.85% 400.67 53.14%
Heating System:SAP 2012 SAP 10
£/year: Improvement: £/year: Improvement:
Main gas boiler 137.43 19.23% 155.20 24.80%
Direct electric 430.79 4.48% 573.51 36.19%
ASHP 239.18 38.55% 318.42 58.94%
Heating System:SAP 2012 SAP 10
£/year: Improvement: £/year: Improvement:
Main gas boiler 123.96 102.55% 139.99 69.60%
Direct electric 380.85 101.27% 507.03 100.85%
ASHP 213.85 100.60% 284.70 100.41%
Reducing Energy BillsVersion 1 – Achieving compliance with Part L1A 2013 of the Building Regulations (direct electric heating option requires 1.31kWp of PV to comply with current Building Regulations)
Version 2 – Improved specification to reduce estimated running costs for space heating and hot water
Version 3 – Improved specification to achieve zero carbon (PV requirements – mains gas boiler 2.94kWp, direct electric 4.91kWp and ASHP 3.27kWp)
Percentage of PV Exported to Grid:
Mains Gas Boiler Direct Electric ASHP
Saving from PV (£/year):Total for Space Heating &
Hot Water (£/year):Saving from PV (£/year):
Total for Space Heating & Hot Water (£/year):
Saving from PV (£/year):Total for Space Heating &
Hot Water (£/year):
NO PV N/A 155.20 N/A 573.51 N/A 318.42
50% -127.94 9.49 -127.94 445.57 -127.94 190.48
40% -141.66 -4.23 -141.66 431.85 -141.66 176.76
30% -155.39 -17.96 -155.39 418.12 -155.39 163.03
20% -169.11 -31.68 -169.11 404.40 -169.11 149.31
10% -182.83 -45.40 -182.83 390.68 -182.83 135.59
Percentage of PV Exported to Grid:
Mains Gas Boiler (2.94kWp of PV) Direct Electric (4.91kWp of PV) ASHP (3.27kWp of PV)
Saving from PV (£/year):Total for Space Heating &
Hot Water (£/year):Saving from PV (£/year):
Total for Space Heating & Hot Water (£/year):
Saving from PV (£/year):Total for Space Heating &
Hot Water (£/year):
NO PV N/A 139.99 N/A 507.03 N/A 284.70
50% -287.13 -147.14 -479.53 27.50 -3919.36 -34.66
40% -317.93 -177.94 -530.97 -23.93 -353.62 -68.91
30% -348.73 -208.74 -582.40 -75.37 -387.87 -103.17
20% -379.53 -239.53 -633.84 -126.80 -422.13 -137.43
10% -410.33 -270.33 -685.27 -178.24 -456.38 -171.68
Reducing Energy BillsVersion 2 – Improved specification to reduce estimated running costs for space heating and hot water (based on 1.31kWp of PV for all options) BASED ON SAP 10 FUEL TARIFFS
Version 3 – Improved specification to achieve zero carbon (PV requirements – mains gas boiler 2.94kWp, direct electric 4.91kWp and ASHP 3.27kWp) BASED ON SAP 10 FUEL TARIFFS
Hydrogen Fuel
Hydrogen Fuel
• Hydrogen is being considered to help decarbonise the gas grid
• 100 properties on Keele University campus to be fed with 20% hydrogen mix – HyDeploy now fully operational (News Keele University on 02 January 2020)
• Requires electrical current to split water molecules into hydrogen and oxygen – zero CO2 if from renewable sources
• If successful move to larger test on a public network in North East, followed by another in the North West possibly this year
• If rolled out across the country it could save 6 million tonnes of CO2/year.
Hydrogen Fuel
• Gas boilers need to be replaced? Not with 20% hydrogen blend
• Some boiler manufacturers are producing prototypes that use 100% hydrogen
• BDR Thermea and Worcester Bosch have a ‘hydrogen-ready’ design capable of converting to 100% hydrogen
• Worcester Bosch want the government to stipulate that by 2025, all new boilers on sale should be hydrogen-ready
• Possible new hybrid-system – heat pumps and hydrogen boilers.
Thank You For ListeningAny Questions?
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