Gestão de energia: 2012/2013 Energy in Buildings Prof. Tânia Sousa [email protected].

Gestão de energia: 2012/2013

Energy in Buildings

Prof. Tânia [email protected]

mailto:[email protected]

Gestão de Energia

Slide 2 of 53

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?

Gestão de Energia

Slide 3 of 53


• Most effective strategy to reduce energy use in buildings (Harvey, 2010):– Reduce heating and cooling loads through a high-

performance 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

Gestão de Energia

Slide 4 of 53

From 220 kWh/m2/year to 20-40 kWh/m2/year

• How much energy reduction can we achieve?– Passive house standard:

heating 15kWh/m2 per yearcooling 15 kWh/m2 per yearTPE 120 kWh/m2 per yearn50 ≤ 0.6 / hour


Triple-glazed windows with internal venetian blinds & mechanical ventilation with 82% heat recovery

Gestão de Energia

Slide 5 of 53

• How much does it cost?


0

50

100

150

200

250

300

350

199

0

19

91

19

92

199

3

199

4

199

5

19

96

19

97

199

8

199

9

20

00

20

01

200

2

200

3

20

04

20

05

20

06

200

7

20

08

20

09

20

10

Add

ition

alIn

vest

men

t(€/

m2 )

ofP

assi

veR

owH

ouse

s 1991 Prototype: experimental house,4 dwellings in Kranichstein usinghandicraft batch production

PH in Groß-Umstadt:Reduced costs bysimplification

Settlement in Wiesbaden:Serially produced windows & structural elements

Settlements in Wuppertal,Stuttgart, Hanover

Row houses in Darmstadt, 80 €/m2

Profitability with contemporary

interest rates & energy prices

Gestão de Energia

Slide 6 of 53

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

– 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

Q U T Area

U C l

Gestão de Energia

Slide 7 of 53


• The effectiveness of the thermal envelope depends of insulation levels in the walls, ceiling and basement

Foam insulation

The most highly insulated houses have U=0.1-0.2 W/m2/K

Blown-in cellulose insulation (fills the gaps)

Vaccum insulation panels

Q U T Area U C l

Gestão de Energia

Slide 8 of 53


• 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

Gestão de Energia

Slide 9 of 53


• 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

Gestão de Energia

Slide 10 of 53


• The effectiveness of the thermal envelope depends on the air leakage– The net heat flow due to an air exchange at rate r is:

– The stack effect promotes air leakage• Cold air is sucked into the lower

part and warm air exits throughthe upper part through craks and openings because it is lighter.

• Stack effect can account for up to40% of heating requirements on cold climates

– The wind effect

p,airQ c V Tair air

Gestão de Energia

Slide 11 of 53


• 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

• Heat Exchangers: – Used in power plants, air conditioners, fridges,

liquefication of natural gas, etc– Transfer energy between fluids at different

temperatures

Energy Balance in Open Systems

22

, ,2 2ji

in i i i out j j ji j

vvdEQ W m h gz m h gz

dt

Direct Contact Heat Exchanger

Counter-flow Heat exchanger

Direct Flow Heat Exchanger

Gestão de Energia

Slide 13 of 53

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?

Gestão de Energia

Slide 14 of 53

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

• House size– The living area per family member

increased by a factor of 3 between 1950 and 2000 in the US

0

20

40

60

80

100

120

140

160

180

200

30% Base 60% Base 60% Upgraded

100% Base 100% Upgraded

En

erg

y In

ten

sity

(kW

h/m

2/y

r)

Heating Cooling LightingEquipment Pumps & fans Server rooms

Gestão de Energia

Slide 15 of 53

Buildings – (almost) Passive solar heating, ventilation & cooling

• Evaporative Cooling:

Gestão de Energia

Slide 16 of 53

Buildings – Passive (almost) solar heating, ventilation & cooling

• Thermal induced ventilation & cooling:

Earth Pipe coolingLarge Atria

Gestão de Energia

Slide 17 of 53


• Wind induced ventilation & cooling:

Wind catcher

Gestão de Energia

Slide 18 of 53


• Passive Solar Heating & Lighting

Shading

Light shelves

Light tubes

Gestão de Energia

Slide 19 of 53

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)

final

primary

E

E

useful

final

E

E

Gestão de Energia

Slide 20 of 53

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)

Gestão de Energia

Slide 21 of 53

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

Gestão de Energia

Slide 22 of 53

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

Gestão de Energia

Slide 23 of 53

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

Gestão de Energia

Slide 24 of 53

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

Gestão de Energia

Slide 25 of 53

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?ref

=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)

http://ec.europa.eu/avservices/video/videoplayer.cfm?ref=I048425&videolang=en&sitelang=en

http://ec.europa.eu/avservices/video/videoplayer.cfm?ref=I048425&videolang=en&sitelang=en

Gestão de Energia

Slide 26 of 53

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?

Gestão de Energia

Slide 27 of 53

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

Gestão de Energia

Slide 28 of 53


• Set Minimum Energy Performance Requirements– Requirements should take into account climatic and local

conditions and cost-effectiveness

Gestão de Energia

Slide 29 of 53


• Energy Performance Requirements should be applied to new buildings & buildings going through major renovations

Gestão de Energia

Slide 30 of 53


• Set System Requirements for: energy performance, appropriate dimensioning, control and adjustment for Technical Building Systems in existing and new buiildings

Gestão de Energia

Slide 31 of 53


• Increase the number of nearly zero energy buildings

Gestão de Energia

Slide 32 of 53

• 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)


Gestão de Energia

Slide 33 of 53

• Regular maintenance of air conditioning and heating systems

• Independent experts


Gestão de Energia

Slide 34 of 53

Implementation of the directives

• Directive 2002/91/EC was implemented with:

• Directive 2010/31/EU was not yet implemented

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).

Gestão de Energia

Slide 35 of 53

• 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

RCCTE – AimRCCTE - Aims

Gestão de Energia

Slide 36 of 53

• Buildings that RCCTE applies to:

RCCTE – Domain of applicationRCCTE – Domain of Application

Residential Comercial Small Big Pnom < 25 kW Pnom > 25 kW Pnom < 25 kW Pnom > 25

kWPnom < 25

kWPnom > 25

kWNew RCCTE RCCTE Old Major

RenovationRCCTE RCCTE

No Renovation

Gestão de Energia

Slide 37 of 53

RCCTE - Outdoor conditions

Reference Outdoor conditions:

• Portugal is divided in winter and summer climatic zones

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

RCCTE – Indoor & Outdoor Conditions

Gestão de Energia

Slide 38 of 53

RCCTE - Outdoor conditions


RCCTE – Outdoor Conditions

Gestão de Energia

Slide 39 of 53

Climate

• Heating Degree-days are:

• 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.

24

se;1i

days Heating

1iiannual 24

where jb TTj

jb TTGDGDGD


Gestão de Energia

Slide 40 of 53

Heating Degree Days – a comparison

0

1000

2000

3000

4000

5000

6000

Edmonto

n

Win

nipeg

Toronto

Vanco

uver

Berlin

Vienna

Helsi

nki

He

ati

ng

De

gre

e D

ay

s (

K-d

ay

s)

Gestão de Energia

Slide 41 of 53

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


Gestão de Energia

Slide 42 of 53

RCCTE – Indices e parameters

Nic Nominal Annual Needs of Useful Energy for Heating

Ni The corresponding maximum permissibleNic ≤ Ni

Nvc Nominal Annual Needs of Useful Energy for Cooling

Nv The corresponding maximum permissibleNvc ≤

NvNac Nominal Annual Energy needs for Domestic Hot Water

Na The corresponding maximum permissibleNac ≤

Na

Ntc Nominal Annual Energy needs for Primary Energy

Nt The corresponding maximum permissibleNtc ≤ Nt

RCCTE – Fundamental thermal Indices

• The thermal behavior of buildings is characterized using the following fundamental thermal indices:

Gestão de Energia

Slide 43 of 53

RCCTE – Indices e parameters

U Heat transfer coefficients of walls

Umax The corresponding maximum permissible

Fs Solar factor of fenestration (for windows not facing NE-NW with area > 5%)

Fsma

x

The corresponding maximum permissible

Additional parameters

Heat Transfer Coefficients of Thermal Bridges

2 x Umax

RCCTE – Additional parameters

• The thermal behavior of buildings is characterized using the parameters:

more demanding for harsher winters

more demanding for harsher summers

Gestão de Energia

Slide 44 of 53

Heating

Heating: Maximum Allowable Needs (Ni) [kWh / (m2.year)]

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 = 4,05 + 0,06885 GD

Form factor: FF = ( (Aext) + ( Aint))/V

GD :: Degree day (ºC * day)

Heating: Nominal Needs (Nic) [kWh / (m2.year)]

Nic = (Qt + Qv – Qgu) / Ap

Qt = 0.024 x GD x (A x U)

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

Nic < Ni

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2

FF [-]

Ni [

kWh

/m2

.an

o]

RCCTE – Fundamental thermal Indices: Heating

to keep the Tint = 20ºC during the heating season

more demanding for smaller FF

Gestão de Energia

Slide 45 of 53

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:

• Passive house standard: 15 kWh/m2/yr

( 0.5) 51.5kWh / m2 / yr

( 0.75) 62.5 kWh / m2 / yr

( 1.25) 80.3 kWh / m2 / yr

( 1.5) 86kWh / m2 / yr

Ni FF

Ni FF

Ni FF

Ni FF

Gestão de Energia

Slide 46 of 53

Cooling

Cooling: Maximum Allowable Needs (Nv) [kWh/(m2.year)]

V1 (North) : Nv = 16

V1 (South) : Nv = 22





Açores : Nv = 21

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

RCCTE – Fundamental thermal Indices: Cooling

to keep the Tint = 25ºC during the cooling season

Gestão de Energia

Slide 47 of 53

Domestic Hot Water

Domestic Hot Water: Maximum Allowable Needs (Na) [kWh / (m2.year)]

MAQS : Reference consumption (40 liters per occupant)

nd : Reference n. of days with DHW (residential:365)

N. of occupants: T0=2; TN=n+1

1 m2 solar panel collector per occupant or 50% of available area if solar exposition is adequate

Na = 0,081 MAQS nd/Ap

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

Qa : (MAQS * 4187 * T * nd) / (3 600 000) (kWh/year)

Maqs = 40 l /occupant . Day*nº occupants

T : 45º (15ºc 60ºc)

Nac < Na

RCCTE – Fundamental thermal Indices: Hot Water

Gestão de Energia

Slide 48 of 53

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

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)

Ntc < Nt

RCCTE – Fundamental thermal Indices: Primary Energy

Gestão de Energia

Slide 49 of 53

Energy label

A A+

B- B

C

D

E

F

G

New buildings

(licensed after 2006)

Old buildings

1

2

3

R

R = Ntc / Nt

Energy Performance Certificate

• Energy Labelling:

Gestão de Energia

Slide 50 of 53

• 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

RCCTE – AimRCESE - Aims

Gestão de Energia

Slide 51 of 53

StructureRCESE – Domain of Application

• Buildings that RCESE applies to:

Residential Comercial Small Big Pnom < 25 kW Pnom > 25 kW Pnom < 25 kW Pnom > 25

kWPnom < 25

kWPnom > 25

kWNew RCCTE RSECE RCCTE RSECE RSECE RSECE Old Major

RenovationRCCTE RSECE RCCTE RSECE RSECE RSECE

No Renovation

RSECE RSECE

Gestão de Energia

Slide 52 of 53

RSECE - Outdoor conditions


• Portugal is divided in winter and summer climatic zones

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)

RCESE – Indoor & Outdoor Conditions

Gestão de Energia

Slide 53 of 53

IEE

IEE : Energy Efficiency Indicator (kgep/(m2.year)]

IEE = IEEi + IEEv + Qout/Ap

HeatingCooling

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

This value must be less than the tabled IEE to the proposed activity

Methodology to compute Energy Performance

Renewable energies are not included

Real energy consumptions (old) or simulation (new)

RCESE - IEE

Gestão de Energia

Slide 54 of 53

Correction Factors

Gestão de Energia

Slide 55 of 53

Heating

Heating: Maximum Allowable Needs (Ni) [kWh / (m2.year)]

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 = 4,05 + 0,06885 GD

Form factor: FF = ( (Aext) + ( Aint))/V

GD :: Degree day (ºC * day)

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2

FF [-]

Ni [

kWh

/m2

.an

o]

Cooling: Maximum Allowable Needs (Nv) [kWh/(m2.year)]







Açores : Nv = 21

Madeira : Nv = 23

GD=1000 degree days

RCESE – Fundamental thermal Indices: Heating & Cooling

Gestão de Energia

Slide 56 of 53

StructureRCESE – Minimum Energy Performance

• Minimum Energy Performance Requirements:

– 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

Residential Comercial

Small Big

Pnom < 25 kW Pnom > 25 kW Pnom < 25 kW Pnom > 25 kW Pnom < 25 kW Pnom > 25 kW

New RCCTE Nic ≤ 80%Ni,RCCTE

Nvc ≤ 80%Nv,RCCT

E

RCCTE Nic ≤ 80%Ni,RCCTE

Nvc ≤ 80%Nv,RCCTE

IEE ≤ IEEmax

IEE ≤ IEEmax

Old Major Renovation

RCCTE RCCTE

No Renovation

Gestão de Energia

Slide 57 of 53

IEE tabled values for existing buildings

Gestão de Energia

Slide 58 of 53

IEEIEE tabled values for new buildings or major renovations

Gestão de Energia

Slide 59 of 53

Energy labelEnergy Performance Indicator

• Energy Labeling:– Depends on IEEnom, on IEEREF

and on the S parameter

Gestão de Energia

Slide 60 of 53

Energy label

IEEref

S

A+ B- C D E F GA B

S

IEE

(kg

ep

/year.

m2)

New buildings

(licensed > 2006)

Old buildings

• Energy Labeling:

Energy Performance Indicator

Gestão de Energia

Slide 61 of 53

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

Gestão de Energia

Slide 62 of 53

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

Gestão de Energia

Slide 63 of 53


• 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;

Gestão de Energia

Slide 64 of 53


• 2010/31/EU considers that the technical, environmental and economic feasibility of high-efficiency 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

Gestão de energia: 2012/2013 Energy in Buildings Prof. Tânia Sousa [email protected].

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Transcript of Gestão de energia: 2012/2013 Energy in Buildings Prof. Tânia Sousa [email protected].