Gestão de energia: 2012/2013
Energy in Buildings
Prof. Tânia Sousa
taniasousa@ist.utl.pt
Gestão de Energia
Energy Consumption in Buildings
• Buildings account for 40% of total energy
consumption in the European union
• What about Portugal?
– In 2010 the final consumption of services +
domestic sector represented 55% of the final
energy consumption
– Do you think that the fraction of primary energy
would be higher or lower? Why?
Slide 2 of 53
Gestão de Energia
Energy Consumption in Buildings
• Most effective strategy to reduce energy use in
buildings (Harvey, 2010):
– Reduce heating and cooling loads through a highperformance envelope
• high degree of insulation, windows with low U values in
cold climates and low solar heat gain in hot climates,
external shading and low air leakage
– Meet the reduced load as much as possible using passive
solar heating, ventilation and cooling techniques while
optimizing the use of daylight
– Use the most efficient mechanical equipment to meet
the remaining loads
– Ensure that individual energy-using devices are as
efficient as possible and properly sized
Slide 3 of 53
Gestão de Energia
Energy Consumption in Buildings
• How much energy reduction can we achieve?
– Passive house standard:
heating  15kWh/m2 per year
cooling  15 kWh/m2 per year
TPE  120 kWh/m2 per year
n50 ≤ 0.6 / hour
From 220 kWh/m2/year to
20-40 kWh/m2/year
Triple-glazed windows with
internal venetian blinds &
mechanical ventilation with 82%
heat recovery
Slide 4 of 53
Gestão de Energia
Energy Consumption in Buildings
• How much does it cost?
1991 Prototype: experimental house,
4 dwellings in Kranichstein using
handicraft batch production
300
PH in Groß-Umstadt:
Reduced costs by
simplification
250
200
Row houses in Darmstadt,
80 €/m2
150
Settlement in Wiesbaden:
Serially produced windows
& structural elements
100
Settlements in Wuppertal,
Stuttgart, Hanover
50
Profitability with
contemporary
interest rates & energy prices
2010
2009
2008
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
0
1990
Additional Investment (€/m2) of Passive Row Houses
350
Slide 5 of 53
Gestão de Energia
Buildings – High Performance Envelope
• The effectiveness of the thermal envelope depends of
insulation levels in the walls, ceiling and basement
– Insulation levels control the heat flow by conduction &
convection through the exterior and the interior
Q  U  T  Area
– U value (W/m2/K), the heat trasnfer coefficient, is equal to the
heat flow per unit area and per degree of inside to outside
temperature difference
– The U value of a layer of insulation depends on its length and
type of material
U C l
Slide 6 of 53
Gestão de Energia
Buildings – High Performance Envelope
• The effectiveness of the thermal envelope depends of
insulation levels in the walls, ceiling and basement
Q  U  T  Area
U C l
The most highly insulated
houses have U=0.1-0.2 W/m2/K
Blown-in cellulose
insulation (fills the gaps)
Foam insulation
Vaccum insulation panels
Slide 7 of 53
Gestão de Energia
Buildings – High Performance Envelope
• The effectiveness of the thermal envelope depends on the
insulation levels of windows
– Windows offer substantially less resistance to the loss of heat
than insulated walls
– Single glazed windows have a typical U-value of 5W/m2/K
which can be reduced to to 2.5 and 1.65W/m2/K with double
and triple glazing because of the additional layers of air
– The U-value of 2.5W/m2/K of double glazed windows can be
reduced to 2.4W/m2/K and 2.3W/m2/K with Argon and krypton
– Double and triple glazing vaccum windows can reduce the U
value to 1.2 and 0.2W/m2/K
Q  U  T  Area
U C l
Slide 8 of 53
Gestão de Energia
Buildings – High Performance Envelope
• The effectiveness of the thermal envelope depends on the
gain/loss energy by radiation
– Windows permit solar energy to
enter and loss of infrared radiation
– Low emissivity coatings reflect more (reduce SHGC), i.e., reduce
heat gains in summer and winter
– Low emissivity coatings can reduce loss of heat by infrared
radiation
– The solar heat gain coefficient, SHGC, is the fraction of solar
radiation inicident on a window that passes through the window
Slide 9 of 53
Gestão de Energia
Buildings – High Performance Envelope
• The effectiveness of the thermal envelope depends on the air
leakage
– The net heat flow due to an air exchange at rate r is:
Q   air c p,air Vair T
– The stack effect promotes air leakage
• Cold air is sucked into the lower
part and warm air exits through
the upper part through craks
and openings because it is lighter.
• Stack effect can account for up to
40% of heating requirements on
cold climates
– The wind effect
Slide 10 of 53
Gestão de Energia
Buildings – High Performance Envelope
• The effectiveness of the thermal envelope depends on the air
leakage
– Careful application of a continuous air barrier can reduces rates
of air leakage by a factor of 5 to 10 compared to standard
practice (enforcement of careful workmanship during
construction)
– Buildings with very low air
leakage require mechanical
ventilation (95% of the available
heat in the warm exhaust air
can be transfered to the
incoming cold air) to keep indoor air quality
Slide 11 of 53
Energy Balance in Open Systems
• Heat Exchangers:
– Used in power plants, air conditioners, fridges,
liquefication of natural gas, etc
– Transfer energy between fluids at different
temperatures


v j2


vi 2
dE
 Q  W   min ,i  hi 
 gzi    mout , j  h j 
 gz j 


dt
2
2
i

 j


Direct Contact Heat
Exchanger
Counter-flow Heat
exchanger
Direct Flow Heat
Exchanger
Gestão de Energia
Buildings – The role of shape, form, orientation and glazed %
• Building shape & form
– Have significant impacts on heating and cooling loads and
daylight because of the relation between surface area and volume
– Which one minimizes heat transfer by conduction and convection?
• Building orientation
– For rectangular buildings the optimal
orientation is with the long axis facing
south
– Why?
Slide 13 of 53
Gestão de Energia
Buildings – The role of shape, form, orientation and glazed %
• Glazing fractions
– High glazing fractions increase energy requirements for heating
and cooling
– There is little additional daylighting benefit once the glazed
fraction increases beyond 30-50% of the total façade area
Energy Intensity (kWh/m2/yr)
200
180
160
140
120
100
80
60
40
20
0
30% Base
Heating
Equipment
60% Base
• House size
60%
Upgraded
Cooling
Pumps & fans
100% Base
100%
Upgraded
Lighting
Server rooms
– The living area per family member
increased by a factor of 3 between
1950 and 2000 in the US
Slide 14 of 53
Gestão de Energia
Buildings – (almost) Passive solar heating, ventilation & cooling
• Evaporative Cooling:
Slide 15 of 53
Gestão de Energia
Buildings – Passive (almost) solar heating, ventilation & cooling
• Thermal induced ventilation & cooling:
Earth Pipe cooling
Large Atria
Slide 16 of 53
Gestão de Energia
Buildings – Passive (almost) solar heating, ventilation & cooling
• Wind induced ventilation & cooling:
Wind catcher
Slide 17 of 53
Gestão de Energia
Buildings – Passive (almost) solar heating, ventilation & cooling
• Passive Solar Heating & Lighting
Shading
Light
tubes
Light
shelves
Slide 18 of 53
Gestão de Energia
Buildings: Mechanical Equipment
• In evaluating the energy efficiency of Mechanical
Equipment the overall efficiency from primary to
useful energy should be taken into account
• This is particularly important in the case of using
Mechanical Equipments that use electricity
(produced from fossil fuels)

E final
E primary
Euseful

E final
Slide 19 of 53
Gestão de Energia
Buildings: Mechanical Equipment for heating
• Furnaces
– heat air and distribute the heated
air through the house using ducts;
– are electric, gas-fired (including
propane or natural gas), or
oil-fired.
– Efficiencies range from 60 to 92%
(highest for condensing furnaces)
• Boilers
– heat water, and provide either hot
water or steam for heating;
– heat is produced from the combustion
of such fuels as natural gas, fuel oil,
coal or pellets.
– Efficiencies range from 75% to 95%
(highest for condensing boilers)
Slide 20 of 53
Gestão de Energia
Buildings: Mechanical Equipment for heating & cooling
• Electrical-resistance heating
– Overall efficiency can be quite
low (primary -> useful)
• Heat-Pumps
–
–
–
–
Overall efficiency can be quite good
It decreases with T
Air-source and ground-source
For cooling & heating
• District Heating/Colling
– For heating & cooling
– Users don’t need
mechanical equipment
Slide 21 of 53
Gestão de Energia
Buildings: Mechanical Equipment for cooling
• Chillers
– Produce cold water which is circulated through the
building
– Electric Chillers: use electricity
– Absorption chillers: use heat (can be waste heat from
cogeneration)
– Electric chillers, COP = 4.0-7.5 (larger units have a
higher COP)
– Absorption chillers, COP = 0.6-1.2
Slide 22 of 53
Gestão de Energia
Buildings: HVAC Systems
• Ventilate and heat or cool big buildings
• All air systems: air at a sufficient low (high) T and in
sufficient volumes is circulated through the building to
remove (add) heat loads
– CAV: constant air volumes
– VAV: variable air volumes
– Air that is circulated in the supply ducts may be taken entirely
from the outside and exhausted to the outside by the return
ducts or a portion of the return air may be mixed with fresh air
– Incoming air needs to be cooled and dehumidified in summer
and heated and (sometimes) humidified in winter
• Restrict air flow to ventilation needs and use additional
systems for additional heating/cooling
• Heat exchangers that transfer heat between outgoing and
incoming air flows
Slide 23 of 53
Gestão de Energia
Buildings: Mechanical Equipment for water heating
• Electrical and natural gas heaters
–
–
–
–
Efficiency of natural gas heaters is 76-85%
Efficiency of oil heaters is 75-83%
There is heat loss from storage tanks
Point-of-use tankless heaters have losses associated
with the pilot light
• There are systems that recover heat
from the warm wastewater with
45-65 % efficiencies
Slide 24 of 53
Gestão de Energia
European Directives
• European Directives on the Energy Performance
of Buildings
– Directive 2002/91/EC of the European Parliament and Council
(on the energy performance of buildings):
– http://ec.europa.eu/avservices/video/videoplayer.cfm?r
ef=I048425&videolang=en&sitelang=en
– This is implemented by the Portuguese Legislation RCCTE and
RCESE
– Directive 2010/31/EU of the European Parliament and Council
(on the energy performance of buildings)
Slide 25 of 53
Gestão de Energia
Directive 2010/31/EU: Aims
•
•
•
•
•
•
•
Reduction of energy consumption
Use of energy from renewable sources
Reduce greenhouse gas emissions
Reduce energy dependence
Promote security of energy supplies
Promote technological developments
Create opportunities for employment & regional
development
• Links with aims of SGCIE?
Slide 26 of 53
Gestão de Energia
Directive 2010/31/EU: Principles
• The establishment of a common methodology to
compute Energy Performace
– including thermal characteristics, heating and air
conditioning instalations, renewable energies, passive
heating and cooling, shading, natural light and design
Slide 27 of 53
Gestão de Energia
Directive 2010/31/EU: Principles
• Set Minimum Energy Performance Requirements
– Requirements should take into account climatic and local
conditions and cost-effectiveness
Slide 28 of 53
Gestão de Energia
Directive 2010/31/EU: Principles
• Energy Performance Requirements should be
applied to new buildings & buildings going
through major renovations
Slide 29 of 53
Gestão de Energia
Directive 2010/31/EU: Principles
• Set System Requirements for: energy
performance, appropriate dimensioning, control
and adjustment for Technical Building Systems in
existing and new buiildings
Slide 30 of 53
Gestão de Energia
Directive 2010/31/EU: Principles
• Increase the number of nearly zero energy
buildings
Slide 31 of 53
Gestão de Energia
Directive 2010/31/EU: Principles
• Establish a system of Energy performace certificates.
– Energy Performance certificates must be issued for
constructed, sold or rented to new tenants
– Buildings occupied by public authorities should set na
example (ECO.AP in 300 public buildings in Portugal)
Slide 32 of 53
Gestão de Energia
Directive 2010/31/EU: Principles
• Regular maintenance of air conditioning and heating
systems
• Independent experts
Slide 33 of 53
Gestão de Energia
Implementation of the directives
• Directive 2002/91/EC was implemented with:
1.
DL 78/2006, the National Energy Certification and Indoor Air Quality in Buildings (SCE).
2.
DL 79/2006, Regulation of HVAC Systems of Buildings (RSECE).
3.
DL 80/2006, Regulation of the Characteristics of Thermal Performance of Buildings (RCCTE).
• Directive 2010/31/EU was not yet implemented
Slide 34 of 53
Gestão de Energia
RCCTE – Aim
RCCTE
- Aims
• General aims:
– Methodology for computing energy performace of
buildings
– Set minimum energy performance standards
– Implement Energy Certification of buildings
• Specific Aims:
– Limitation of annual energy needs for heating, cooling,
domestic hot water and primary energy
– Limitation of heat transfer coefficients
– Limiting of solar factors
– Installation of solar panels
Slide 35 of 53
Gestão de Energia
– Domain of application
RCCTE – RCCTE
Domain
of Application
• Buildings that RCCTE applies to:
Residential
Comercial
Small
New
Old
Major
Renovation
No
Renovation
Pnom < 25
kW
RCCTE
RCCTE
Pnom > 25
kW
Pnom < 25
kW
RCCTE
RCCTE
Big
Pnom > 25
kW
Pnom < 25
kW
Pnom > 25
kW
Slide 36 of 53
Gestão de Energia
- Outdoor conditions
RCCTE – Indoor &RCCTE
Outdoor
Conditions
Reference Indoor conditions
• 20ºC in heating season
• 25ºC and 50% relative humidity in the cooling season
• Consumption of 40 liters of water at 60ºC/occupant . day
Reference Outdoor conditions:
• Portugal is divided in winter and summer climatic zones
Slide 37 of 53
Gestão de Energia
- Outdoor conditions
RCCTE –RCCTE
Outdoor
Conditions
Reference Outdoor conditions:
Slide 38 of 53
Gestão de Energia
RCCTE – Outdoor Conditions
Climate
• Heating Degree-days are:
GDannual 
Heating days
 GD
i 1
i
where GDi 
24
Tb  T j
j 1;se Tb T j
24

• Where:
• Tb is the desired indoor temperature (20ºC)
• Tj is the temperature outside the hours j
• The Degree-days are calculated for an entire year
• For example, to Lisbon, for Tb = 20 º C, heating
degree days are 1190 º C.day. Knowing the
heating season is 6 months (180 days), the
average daily GD (GDI) will be 6.6 º C.
Slide 39 of 53
Gestão de Energia
Heating Degree Days – a comparison
5000
4000
3000
2000
1000
i
H
el
si
nk
a
nn
Vi
e
er
B
ou
Va
nc
lin
r
ve
to
ro
n
To
ni
pe
g
in
W
m
on
t
on
0
Ed
Heating Degree Days (K-days)
6000
Slide 40 of 53
Gestão de Energia
RCCTE – Outdoor Conditions
Climate
• Outdoor project temperature
• The outside project temperature is calculated on
a cumulative probability of occurrence of 99%,
97.5%, 95% and 90%.
• A cumulative probability of occurrence of 99%
means that in summer the temperature indicated
is exceeded only in probabilistic terms, 1% of the
time, ie, 30 hours per year (e.g. Lisbon).
Probabilidade Acumulada de Ocorrência
Temperatura de Projecto (ºC)
90%
27
95%
29.4
97.5%
31.4
99%
33.3
Slide 41 of 53
Gestão de Energia
RCCTE –thermal
Indices e parameters
RCCTE – Fundamental
Indices
• The thermal behavior of buildings is characterized
using the following fundamental thermal indices:
Nic
Nominal Annual Needs of Useful Energy for Heating
Ni
The corresponding maximum permissible
Nvc
Nv
Nominal Annual Needs of Useful Energy for Cooling
Nac
Nominal Annual Energy needs for Domestic Hot Water
Na
The corresponding maximum permissible
Ntc
Nominal Annual Energy needs for Primary Energy
Nt
The corresponding maximum permissible
The corresponding maximum permissible
Nic ≤ Ni
Nvc ≤ Nv
Nac ≤ Na
Ntc ≤ Nt
Slide 42 of 53
Gestão de Energia
– Indicesparameters
e parameters
RCCTE – RCCTE
Additional
• The thermal behavior of buildings is characterized
using the parameters:
more demanding for harsher winters
more demanding for harsher summers
Additional parameters
U
Umax
Heat transfer coefficients of walls
The corresponding maximum permissible
Heat Transfer Coefficients of Thermal Bridges
2 x Umax
Fs
Fsmax
Solar factor of fenestration (for windows not facing NE-NW with area > 5%)
The corresponding maximum permissible
Slide 43 of 53
Gestão de Energia
Heating
RCCTE – Fundamental thermal Indices: Heating
FF ≤ 0.5
:: Ni = 4,5 + 0,0395 GD
0,5 < FF ≤ 1 :: Ni = 4,5 + (0,021+ 0,037FF) GD
1 < FF ≤ 1,5 :: Ni = [4,5 +(0,021+ 0,037FF) GD] (1,2 – 0,2 FF)
FF > 1,5
Ni [kWh/m2.ano]
Heating: Maximum Allowable Needs (Ni) [kWh / (m2.year)]
:: Ni = 4,05 + 0,06885 GD
0
Form factor: FF = ( (Aext) +  ( Aint))/V
GD :: Degree day (ºC * day)
0.5
1
1.5
2
FF [-]
more demanding for smaller FF
Nic < Ni
Heating: Nominal Needs (Nic) [kWh / (m2.year)]
Nic = (Qt + Qv – Qgu) / Ap
Qt = 0.024 x GD x  (A x U)
to keep the Tint = 20ºC during the heating season
Qv = 0,024 (0,34 x R x Ap x Pd) x GD
Qt: heat loss by conduction & convection through the surrounding
Qv: heat losses resulting from air exchange
Qgu: solar gain and internal load
Slide 44 of 53
Gestão de Energia
Current average residential heating energy use (Harvey, 2010)
• 60-100 kWh/m2/yr for new residential buildings
in Switzerland and Germany
• 220 kWh/m2/yr average of existing buildings in
Germany
• 250-400 kWh/m2/yr for existing buildings in
central and eastern Europe
• For Lisbon the maximum heating allowable needs
are:
Ni ( FF
Ni ( FF
Ni ( FF
Ni ( FF
 0.5)  51.5kWh / m2 / yr
 0.75)  62.5 kWh / m2 / yr
 1.25)  80.3 kWh / m2 / yr
 1.5)  86 kWh / m2 / yr
• Passive house standard: 15 kWh/m2/yr
Slide 45 of 53
Gestão de Energia
RCCTE – Fundamental thermal Indices: Cooling
Cooling
Cooling: Maximum Allowable Needs (Nv) [kWh/(m2.year)]
V1 (North) : Nv = 16
V2 (North) : Nv = 18
V3 (North) : Nv = 26
Açores : Nv = 21
V1 (South) : Nv = 22
V2 (South) : Nv = 32
V3 (South) : Nv = 32
Madeira : Nv = 23
Cooling: Nominal Needs (Nvc) [kWh / (m2.year)]
Nvc = Qg * (1 - ) / Ap (kWh/m2year)
Qg : Total gross load (internal + walls + solar + air renewal)
:
Load Factor
Nvc < Nv
to keep the Tint = 25ºC during the cooling season
Slide 46 of 53
Gestão de Energia
Domestic
Water
RCCTE – Fundamental thermal Indices:
HotHot
Water
Domestic Hot Water: Maximum Allowable Needs (Na) [kWh / (m2.year)]
Na = 0,081 MAQS nd/Ap
MAQS : Reference consumption (40 liters per occupant)
1 m2 solar panel collector per
occupant or 50% of available area
if solar exposition is adequate
nd : Reference n. of days with DHW (residential:365)
N. of occupants: T0=2; TN=n+1
Domestic Hot Water: Nominal Needs (Nac) [kWh / (m2.year)]
Nac = (Qa/ηa – Esolar – Eren)/Ap
Qa: Conventional useful energy requirements
ηa: Efficiency of the conventional systems
ESolar: Contribution of solar thermal panels for DHW
Eren: Contribution to other renewable for DHW
Nac < Na
Qa : (MAQS * 4187 * T * nd) / (3 600 000) (kWh/year)
Maqs = 40 l /occupant . Day*nº occupants
T : 45º (15ºc  60ºc)
Slide 47 of 53
Gestão de Energia
Primary
energy
RCCTE – Fundamental thermal Indices: Primary
Energy
Primary energy: Maximum Allowable Needs (Nt) [kgep/(m2.year)]
Nt = 0,9 (0,01Ni + 0,01 Nv + 0,15 Na)
Primary energy : Nominal Needs (Ntc) [kgep/(m2.year)]
Ntc = 0,1 (Nic/ηi)Fpui + 0,1 (Nvc/ηv)Fpuv + Nac Fpua
Fpu : Conversion factor from final energy to primary energy
Electricity: Fpu = 0.290 kgep / kWh
Ntc < Nt
Fuels:
Fpu = 0.086 kgep / kWh
In the absence of more precise data consider, eg:
Electrical resistance = 1
Boiler fuel gas = 0.87
Heat Pump = 3 (cooling) and 4 (heating)
Slide 48 of 53
Gestão de Energia
Energy label
Energy Performance Certificate
• Energy Labelling:
R = Ntc / Nt
R
A
1
B-
A+
B
New buildings
(licensed after 2006)
C
2
D
E
3
Old buildings
F
G
Slide 49 of 53
Gestão de Energia
RCCTE – Aim
RCESE
- Aims
• General aims:
– Methodology for computing energy performace of
buildings
– Set minimum energy performance standards
– Implement Energy Certification of buildings
– Regular inspection of boilers and air conditioning in
buildings
• Specific Aims:
– Limitation of annual energy needs for heating, cooling,
and primary energy
– Limitation of heat transfer coefficients
– Limiting of solar factors
– Maintenance of HVAC systems
– Monitoring and energy audits
Slide 50 of 53
Gestão de Energia
Structure
RCESE – Domain of Application
• Buildings that RCESE applies to:
Residential
Comercial
Small
New
Old
Major
Renovation
No
Renovation
Pnom < 25
kW
RCCTE
RCCTE
Pnom > 25
kW
RSECE
RSECE
Pnom < 25
kW
RCCTE
RCCTE
Big
Pnom > 25
kW
RSECE
RSECE
Pnom < 25
kW
RSECE
RSECE
Pnom > 25
kW
RSECE
RSECE
RSECE
RSECE
Slide 51 of 53
Gestão de Energia
- Outdoor conditions
RCESE – Indoor &RSECE
Outdoor
Conditions
Indoor conditions
• the same of RCCTE
• air velocity can not exceed 0,2 m/s
•QAI (minimum air renovation and maximum concentration of air polutants)
Reference Outdoor conditions:
• Portugal is divided in winter and summer climatic zones
Slide 52 of 53
Gestão de Energia
IEE
RCESE - IEE
Methodology to compute Energy Performance
IEE : Energy Efficiency Indicator (kgep/(m2.year)]
IEE = IEEi + IEEv + Qout/Ap
Heating
Cooling
This value must be less than the
tabled IEE to the proposed activity
Other consumptions
IEEi = (Qaq / Ap) x Fci
Qaq : primary energy consumption for heating (kgep/year)
IEEv = (Qarr / Ap) x Fcv
Qarr : primary energy consumption for cooling (kgep/year)
Fci : Correction factor for heating, Fci = Ni1/Nii
Fcv : Correction factor for cooling, Fcv = Nv1/Nvi
Renewable energies are not included
Real energy consumptions (old) or simulation (new)
Slide 53 of 53
Gestão de Energia
Correction Factors
Slide 54 of 53
Gestão de Energia
Heating
RCESE – Fundamental thermal Indices: Heating & Cooling
Heating: Maximum Allowable Needs (Ni) [kWh / (m2.year)]
:: Ni = 4,5 + 0,0395 GD
0,5 < FF ≤ 1 :: Ni = 4,5 + (0,021+ 0,037FF) GD
1 < FF ≤ 1,5 :: Ni = [4,5 +(0,021+ 0,037FF) GD] (1,2 – 0,2 FF)
FF > 1,5
:: Ni = 4,05 + 0,06885 GD
Form factor: FF = ( (Aext) +  ( Aint))/V
Ni [kWh/m2.ano]
FF ≤ 0.5
0
GD :: Degree day (ºC * day)
0.5
1
1.5
2
FF [-]
GD=1000 degree days
Cooling: Maximum Allowable Needs (Nv) [kWh/(m2.year)]
V1 (North) : Nv = 16
V2 (North) : Nv = 18
V3 (North) : Nv = 26
Açores : Nv = 21
V1 (South) : Nv = 22
V2 (South) : Nv = 32
V3 (South) : Nv = 32
Madeira : Nv = 23
Slide 55 of 53
Gestão de Energia
Structure
RCESE – Minimum Energy Performance
• Minimum Energy Performance Requirements:
Residential
New
Old
Major
Renovation
Pnom < 25 kW
RCCTE
RCCTE
Pnom > 25 kW
Nic ≤
80%Ni,RCCTE
Nvc ≤
80%Nv,RCCTE
Comercial
Pnom < 25 kW
RCCTE
RCCTE
Small
Pnom > 25 kW
Nic ≤
80%Ni,RCCTE
Big
Pnom < 25 kW
Pnom > 25 kW
IEE ≤ IEEmax
Nvc ≤
80%Nv,RCCTE
IEE ≤ IEEmax
No
Renovation
– If the minimum energy performance requirements of old
big comercial buildings are not met than there is na
energy audit to develop an energy rationalization plan
and all efficiency measures with economic viability have
to be implemented
Slide 56 of 53
Gestão de Energia
IEE tabled values for existing buildings
Slide 57 of 53
Gestão de Energia
IEE
IEE tabled values for new buildings or major renovations
Slide 58 of 53
Gestão de Energia
label
Energy Performance Energy
Indicator
• Energy Labeling:
– Depends on IEEnom, on IEEREF
and on the S parameter
Slide 59 of 53
Gestão de Energia
label
Energy Performance Energy
Indicator
• Energy Labeling:
Old buildings
IEE
(kgep/year. m2)
New buildings
S
(licensed > 2006)
IEEref
S
A+
A
B
B-
C
D
E
F
G
Slide 60 of 53
Gestão de Energia
System Requirements for HVAC
• Limit the installed power:
– Heating or cooling PNOM < 1.4 of the power needed
• Promote Energy Efficiency
– If PNOM> 100 kW than HVAC system with centralized heat
production
– The connection to centralized heating and cooling systems (if
available) is mandatory
– The heating power obtained by Joule effect cannot exceed 5%
of the heating thermal power
• Control and regulation systems
– Control confort temperatures
– Turn off when the space is not used
• Monitoring (PNOM> 100 kW ) and Energy Management
Systems (PNOM> 200 kW ) with centralized optimization
(PNOM> 250 kW )
• Audits to big boilers and AC
Slide 61 of 53
Gestão de Energia
Differences between Directives 2002/91/EC and 2010/31/EU
• 2010/31/EU has requirements on increasing the
number of nearly zero-energy buildings;
• 2010/31/EU has requirements on the minimum
energy performance of all (not only on big)
existing buildings subject to major renovations
• In 2010/31/EU the framework for energy
performance:
– Based on the computed or actual annual energy
consumed in order to meet different needs associated
with typical behavior
– Energy performance indicator and a numerical indicator
of primary energy consumption
Slide 62 of 53
Gestão de Energia
Differences between Directives 2002/91/EC and 2010/31/EU
• 2010/31/EU sets the minimum energy
performance requirements targeting cost-optimal
levels (to be calculated in accordance with a
comparative methodology framework).
• 2010/31/EU considers that the methodology for
the identification of cost-optimal levels should :
– take into account use patterns, outdoor climate
conditions, investment costs and maintenance and
operating costs;
– be computed for reference buildings with different
functionalities and geographic locations;
– define the efficiency measures that should be assessed;
– consider the expected economic life-cycle of the building;
Slide 63 of 53
Gestão de Energia
Differences between Directives 2002/91/EC and 2010/31/EU
• 2010/31/EU considers that the technical,
environmental and economic feasibility of highefficiency alternative systems such as
(decentralized energy supply systems based on
energy from renewable sources, cogeneration,
district or block heating or cooling, heat pumps)
should be considered for all (not only > 1000 m2)
new buildings
• 2010/31/EU considers that when all buildings
(not only > 1000 m2) undergo major renovation,
the energy performance of the building or the
renovated part thereof is upgraded in order to
meet minimum energy performance requirements
Slide 64 of 53