Transcript Slide 1

Estonian cost optimal calculation
and implementation
in the
code
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to edit Master title
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14.03.2013 CA-EPBD III Madrid
Jarek Kurnitski
Professor, Tallinn University of Technology
Vice-president REHVA
[email protected]
www.nzeb.ee
Presentation outline
Estonian cost optimal calculations:
•
conducted as a financial calculation in 2011
Implementation into building code:
• cost optimal energy performance minimum reqs. for new
buildings and major renovations apply from Jan 9, 2013
Situation with energy frames
• In most of countries, on site renewable energy production is
subtracted from delivered energy (must for Cost Optimal)
• Differences in energy frames:
– primary energy not yet used in all countries (must for Cost Optimal)
– Some countries (Germany, France) use reference building method,
fixed values in other countries
– Both simulation (Estonia, Finland) and monthly methods (Germany,
Denmark) used
• Inclusion of energy flows depends on country:
– Germany/residential – heating energy only (space heating, DHW and heating of
ventilation air)
– Germany/non-residential – cooling and lighting also included (appliances not)
– Denmark – appliances and in residential also lighting not included
– Sweden – appliances and user’s lighting not included (facility lighting incl.)
– Estonia, Finland, Norway – appliances and lighting included (all inclusive)
Federation of European Heating, Ventilation and Air-conditioning Associations
Energy frames, exported energy
• Exported electricity can be taken into account on annual basis
(full utilization), monthly bases (limited to the amount of the
delivered electricity each month and the rest of exported is not
accounted) or is not taken into account
• Full utilization (annual bases) (must for Cost Optimal?):
– Denmark, Estonia, net plus energy program in Germany
• Monthly bases:
– Germany, Sweden? (not decided)
• Not accounted
– Finland, Norway, Italy
• Most of energy frames not yet
ready to support exported energy
Federation of European Heating, Ventilation and Air-conditioning Associations
Estonian Cost Optimal: Seven step
systematic procedure (Kurnitski et al. Energy and Buildings 43 (2011)
1. selection of the reference building/buildings
2. definition of construction concepts based on building
envelope optimization for fixed specific heat loss levels (from
business as usual construction to highly insulated building
envelope in 4 steps)
3. specification of building technical systems
4. energy calculations for specified construction concepts
5. post processing of energy results to calculate delivered,
exported and primary energy
6. economic calculations for construction cost and net present
value of operating cost
7. sensitivity analyses (discount rate, escalation of energy
prices and other parameters)
•
•
All this steps are independent, iterative approach not needed for
residential buildings, because of the specific heat loss method used
Worked well for residential, non-residential buildings less predictable
Reference buildings – proposed by the society of
Estonian architects, 3 out of 6 buildings shown
Jarek Kurnitski
9.11.20
Pre-optimized building envelope
The specific heat loss coefficient includes transmission and infiltration losses
through the building envelope and is calculated per heated net floor area:
U i  Ai  j  l j   p  n p  ρa  ca  Vi
H

A floor
A floor
Construction concepts
DH 0.42
“Nearly zero”
DH 0.58
DH 0.76
DH 0.96
“BAU”
0.42
0.58
0.76
0.96
External wall
170 m2
20cm LECA block, plaster
+ 35cm EPS-insulation
20cm LECA block, plaster
+ 25cm EPS-insulation
20cm LECA block, plaster
+ 20cm EPS-insulation
20cm LECA block, plaster
+ 15cm EPS-insulation
U 0.1 W/m K
U 0.14 W/m K
U 0.17 W/m K
U 0.23 W/m K
Roof
93 m2
Wooden beams, metal
sheet, 80cm min.wool
insulation, concrete slab
Wooden beams, metal
sheet, 50cm min.wool
insulation, concrete slab
Wooden beams, metal
sheet, 32cm min.wool
insulation, concrete slab
Wooden beams, metal
sheet, 25cm min.wool
insulation, concrete slab
U 0.06 W/m K
U 0.09 W/m K
U 0.14 W/m K
U 0.18 W/m K
Concrete slab on ground,
70cm EPS insulation
Concrete slab on ground,
45cm EPS insulation
Concrete slab on ground,
25cm EPS insulation
Concrete slab on ground,
18cm EPS insulation
U 0.06 W/m K
U 0.09 W/m K
U 0.14 W/m K
U 0.18 W/m K
Specific heat
loss coefficient
H/A, W/m2K
Ground floor
93 m2
Leakage rate
q50, m3/(h m2)
Windows
48 m2
U-value
glazing/frame/total
g-value
2
2
2
0.6
2
2
2
2
2
2
2
2
2
1.0
1.5
3.0
4mm-16mmAr-SN4mm16mmAr-SN4mm
Insulated frame
4mm-16mmAr-4mm16mmAr-SN4mm
Insulated frame
4mm-16mm-4mm16mmAr-SN4mm
4mm-16mmArSN4mm
Common frame
0.6/0.7 W/m K
2
0.7 W/m K
0.46
0.8/0.8 W/m K
2
0.8 W/m K
0.5
1.0/1.3 W/m K
2
1.1 W/m K
0.55
2
2
2
2
1,1/1,4 W/m K
2
1,2 W/m K
0.63
DH 0.42
“Nearly zero”
DH 0.58
DH 0.76
DH 0.96
“BAU”
80 l/s, SFP 1.7
3
kW/(m /s), AHU HR
80%
80 l/s, SFP 2.0
3
kW/(m /s), AHU HR
80%
80 l/s, SFP 2.0
3
kW/(m /s), AHU HR
80%
5
6
8
9
5
5
5
8
Ventilation rate
80 l/s, SFP 1.5
l/s, specific fan
3
kW/(m /s), AHU HR
power SFP,
85%
temperature
efficiency AHU HR
Heating
capacity, kW
Cooling
capacity, kW
Net energy need kWh/(m2 a)
Space heating
Supply air
heating in AHU
Domestic hot
water
Cooling
Fans and
pumps
Lighting
Appliances
Total net
energy need
22.2
36.8
55.1
71.5
4.1
5.7
5.7
5.7
29.3
29.3
29.3
29.3
13.6
11.1
9.2
15.0
7.9
8.8
10.0
10.0
7.3
7.3
7.3
7.3
18.8
18.8
18.8
18.8
103.2
117.8
135.5
157.7
Energy simulations
•
•
Results of the detached house as a function of insulation level
(construction concepts) and heat source
From left to right from passive house building envelope to BAU
Energy cost data used (2011 data)
•
•
•
•
•
•
•
•
Electricity
Natural gas
m3/year)
Pellet
Heating oil
District heating
boiler)
0.0983 €/kWh + VAT (20%)
0.0395 €/kWh + VAT (20%) (consumption over 750
0.033 €/kWh + VAT (20%)
0.0717 €/kWh + VAT (20%)
0.0569 €/kWh + VAT (20%) (Tallinn, natural gas
Escalation
2% (in base case)
Discount rate
3% (in base case)
In sensitivity analyses:


Escalation 3% and discount rate 3%
Escalation 1% and discount rate 3%
Incremental cost calculation
•
Construction cost calculation for energy performance related works
and components included:




•
•
•
thermal insulation
windows
air handling units (without ductwork)
heat supply solutions (boilers, heat pumps etc.)
Labour costs, material costs, overheads, the share of project
management and design costs, connection fees, and VAT were
included in the energy performance related construction cost
Global energy performance related cost was calculated as a sum
of the energy performance related construction cost and
discounted energy costs for 30/20 years (res./non-res.), including
all electrical and heating energy use
As the total construction cost was not calculated, the global
incremental cost was used (relative to the business as usual
construction):
C I   Ca ,i  Rd i 
30
Cg 
i 1
A floor

C gref
A floor
Global incremental cost calculation: “Gas boiler” cases
•
•
The global cost included, first divided by net heated floor area of 171 m2
The values of the reference building (DH 0.96) subtracted
Global energy performance related cost included in the calculations,
net present value, €
Building envelope (thermal insulation and windows, structures not incl.)
Ventilation units (ductwork not included)
Condensing gas boiler (distribution system not included)
Solar collectors 6m 2
Connection price: Gas
Energy cost for natural gas, NPV
Energy cost for electricity, NPV
Global cost included in the calculations, NPV, €
DH 0.42
30602
5474
6917
4479
2455
10100
20081
80108
DH 0.58
26245
3445
6917
4479
2455
14063
20081
77685
DH 0.76
21167
3445
6917
0
2455
22208
20407
76599
DH 0.96 (ref.)
17611
3445
6917
0
2455
26196
21422
78047
Global incremental energy performance related cost included in the
calculations, relative to the reference building, net present value, €/m 2
Building envelope (thermal insulation and windows, structures not incl.)
Ventilation units (ductwork not included)
Condensing gas boiler (distribution system not included)
Solar collectors 6m 2
Connection price: Gas
Energy cost for natural gas, NPV
Energy cost for electricity, NPV
Global incremental cost included in the calculations, NPV, €/m 2
DH 0.42
75,9
11,9
0,0
26,2
0,0
-94,1
-7,8
12,0
DH 0.58
50,5
0,0
0,0
26,2
0,0
-70,9
-7,8
-2,1
DH 0.76
20,8
0,0
0,0
0,0
0,0
-23,3
-5,9
-8,5
DH 0.96 (ref.)
0,0
0,0
0,0
0,0
0,0
0,0
0,0
0,0
Example of cost optimal: Estonian detached house
3% discount rate and 2% escalation
(Kurnitski et al. Energy and Buildings 43 (2011))
150
Global incremental cost (NPV), €/m2
nZEB
100
Gas
Pellet
AWHP
50
GSHP
Min.req.
Electric
BAU
ref.
Cost optimal
Oil
DH
0
100
150
200
250
Cost optimals with
<2 €/m2 difference
-50
Primary energy, kWh/(m2 a)
•
•
•
•
AWHP – air to water heat pump, GSHP – ground source heat pump, DH – district heating
W/o PV, 4 insulation levels from left to right: 0,42, 0,58, 0,76 ja 0,96 specific heat loss H/A
H/A 0,42 ja 0,58 are calculated with solar collectors
nZEB +239 €/m2 construction cost (PE = 40 ), W/o PV +93 €/m2 (PE = 80)
Results without solar collectors
Global incremental cost (NPV), €/m2
150
100
Gas
Pellet
AWHP
50
GSHP
Electric
Oil
DH
0
100
150
200
250
-50
Primary energy, kWh/(m2 a)
•
•
With or w/o solar collectors? Calculate both with and without solar collectors!
Cost optimality depended on energy source: with reasonably cheap gas, it was
optimal to increase the insulation thickness by one step instead of solar collectors
Breakdown of the global cost components
Extra global cost < extra investment cost
Gas
DH 0.96
17611
3445 9373 0
26196
Building envelope
21422
Ventilation units
DH 0.76
21167
DH 0.58
3445 9373 0
26245
22208
20407
3445 9373 4479 14063
Gas boiler
Solar collectors 6m2
20081
Energy cost for heating
DH 0.42
30602
0
5474 9373 4479 10100
20000
40000
Energy cost for electricity
20081
60000
80000
100000
NPV, €
Ground source heat pump
DH 0.96
17611
3445
15542
0
19067
Building envelope
21422
Ventilation units
DH 0.76
21167
DH 0.58
3445
26245
15542
3445
0
15542
16356
20407
4479 10189
Ground source heat pump
Solar collectors 6m2
20081
Energy cost for heating
DH 0.42
30602
0
20000
5474
15542
40000
44797496
60000
Energy cost for electricity
20081
80000
100000
NPV, €
•
•
Extra global cost is less than extra investment cost, because of reduced
energy use
Improvement from DH 0.76 to DH 0.42 means extra investment cost of 15 943
€ corresponding to 6757 € NPV in GSHP case
Apartment building
Specific heat
loss coefficient
H/A, W/m2K
Heating capacity, kW (te -21oC)
Cooling capacity,
kW
AB 0.23
“Nearly zero”
AB 0.32
AB 0.43
AB 0.52
“BAU“
0.231
0.315
0.431
0.521
46
52
59
65
48
50
51
70
Net energy need kWh/(m2 a)
Space heating
Ventilation
heating
Domestic hot
water
Cooling
Fans and
pumps
Lighting
Appliances
Total net
energy need
7.1
13.0
21.9
28.4
4.7
6.6
6.9
7.0
35.6
35.6
35.6
35.6
11.3
9.9
8.6
14.5
8.9
9.9
11.6
11.6
7.0
7.0
7.0
7.0
22.3
22.3
22.3
22.3
96.9
104.3
113.9
126.4
Apartment building
3% discount rate and 2% escalation
Global incremental cost (NPV), €/m2
150
100
Gas
Pellet
AWHP
50
GSHP
Electric
Oil
DH
0
90
110
130
-50
Primary energy, kWh/(m2 a)
150
170
Office building
Specific heat
loss coefficient
H/A, W/m2K
Heating capacity, kW (te -21oC)
Cooling capacity,
kW
OB 0.25
“Nearly zero”
OB 0.33
“Low”
OB 0.45
OB 0.55
“BAU“
0.245
0.334
0.454
0.548
151
160
172
181
155
156
160
193
Net energy need kWh/(m2 a)
Space heating
Ventilation
heating
Domestic hot
water
Cooling
Fans and
pumps
Lighting
Appliances
Total net
energy need
5.8
11.4
21.9
29.0
2.8
4.1
6.2
6.4
7.4
7.4
7.4
7.4
32.9
30.9
28.9
37.8
7.3
7.9
10.9
10.9
18.9
18.9
18.9
18.9
23.7
23.7
23.7
23.7
98.8
104.3
117.9
134.1
Office building
3% discount rate and 2% escalation
Global incremental cost (NPV), €/m2
150
100
Gas
Pellet
AWHP
50
GSHP
Electric
Oil
DH
0
90
110
130
-50
Primary energy, kWh/(m2 a)
150
170
Distance from cost optimal to nZEB
Investments needed for nZEB in the reference detached house:
• +16 000 € investment in GSHP case led to 75 kWh/(m2 a) primary
energy
• + 5 kW solar PV installation with about 25 000 € investment (2011 data)
•
Results in about nZEB=40 kWh/(m2 a) primary energy
•
Distance to nZEB the reference detached house :
41 000 € extra construction cost
239 €/m2 extra construction cost – (2011 data)
(W/o PV +93 €/m2)
• In the reference apartment and office buildings:
80-90 €/m2 extra construction cost (2011 data)
Cost optimal solutions – main principles
Building envelope:
- External wall U=0.14…0.17 (small/large building)
- Window U=0.8
- Roof and external floor U=0.09…0.14
Technical systems:
- Specific fan power of ventilation SFP=1.7…2.0
- Heat recovery 80% (possible also with exhaust
air heat pump/ventilation radiators)
- Lighting <12 W/m2
- Hydronic heating (electrical not possible)
- Free cooling loop in the cooling system
Architectural preconditions:
- Reasonable compactness
- Solar shading
- Controlled window to wall ratio (“glass building” needs double skin)
Implementation into the regulation




Energy frame based on primary energy
Exported energy in the energy frame
Lighting&Appliances included, i.e. calculated ≈ measured
Dynamic simulation required for non-residential
•
Implementation was possible by just adjusting primary energy
requirements, given for 9 building types
Primary energy reqs. improved by about 20-40% depending on building
type and energy source (some adjustments in the standard use of
buildings and PE factor of electricity)
Safety margin of 10 to 15% was generally applied to cost optimal
primary energy
Cost optimal regulation in force since Jan 9, 2013 both for new
buildings and major renovation
•
•
•
Estonian system boundaries
REHVA system boundaries
Federation of European Heating, Ventilation and Air-conditioning Associations
Estonian regulation VV No 68: 2012
implemented nZEB and cost optimal
Primary energy requirements for 9 building types (apply from Jan 9, 2013)
nZEB
A
kWh/(m2 a)
Low energy
B
kWh/(m2 a)
Min.req. new
C (cost opt.)
kWh/(m2 a)
Min.req. maj.ren.
D (cost opt.)
kWh/(m2 a)
Detached houses
50
120
160
210
Apartment buildings
100
120
150
180
Office buildings
100
130
160
210
• nZEB and low energy requirements officially given together with
cost optimal minimum reqs (not yet mandatory)
• Conversion factors:
– Electricity 2.0
– Fossil fuels 1.0
– District heat 0.9
– Renewable fuels 0.75
Estonian regulation
•
•
•
VV No 68: 2012 – Minimum requirements for energy performance
MKM No 63: 2012 – Energy calculation methodology
Compliance assessment:
 For all buildings equipped with cooling, energy performance calculation shall
be based on dynamic building simulation
 Requirements are specified for simulation tools, which refer to relevant
European, ISO, ASHRAE or CIBSE standards, IEA BESTEST or other
equivalent generally accepted method.
 For residential buildings without cooling, monthly energy calculation
methods may be also used.
 An exception is for detached houses, which have an alternative compliance
assessment method based on tabulated specific heat loss values
•
Summer thermal comfort:
 If no cooling installed, a dynamic temperature simulation in critical rooms
required in order to comply with summer temperature requirements (25°C +
100 °Ch in non-residential and 27°C + 150 °Ch in residential buildings
during three summer months simulated with TRY)
 An exception is for detached house, there the compliance may be
alternatively shown with tabulated values for solar protection, window sizes
and window airing
How to compare min. requirements?
Detached house (1/2013 data)
• Recalculation from primary
energy to delivered energy
needed, which can be
compared in all countries
• The figure shows maximum
allowed delivered energy
without household electricity
(i.e. delivered energy to
heating, hot water and
ventilation systems) in each
country for fossil fuel or
electrical heating
Oil or gas boiler
Electrical heating
100
Max delivered energy, kWh/(m2a)
• 150 m2 detached house
considered
• Degree-day correction (base
17°C) to Copenhagen, energy
use for hot water heating 25
kWh/(m2a)
120
80
60
40
20
0
Denmark
Norway
Sweden
Estonia
Finland
Apartment and office buildings with district
heating (1/2013 data)
140
Apartment building
Of f ice building
Max delivered energy, kWh/(m2a)
120
100
80
60
40
20
0
Denmark
•
Norway
Sweden
Estonia
Finland
Maximum allowed delivered energy for heating, hot water and ventilation
systems in apartment buildings and for office buildings (lighting included)
with district heating