Project in brief

Building characteristics

Owner: Politecnico di MilanoYear Of erectiOn: 1961net flOOr area: 2,272 m²UtilizatiOn: University building – mainly officescOnsUMPtiOn Of electricit Y: 580,000 kwh/a (2008/09), 270 kwh/(m²�a) (considering cooling for server room) cOnsUMPtiOn Of heating: 200,000 kwh/a (2006), 88 kwh/(m²�a)BUilding envelOPe: Building is made of bricks and con­crete. windows are out of aluminium, double glazed, endowed with a horizontal shadowing system BUilding services:

π district heating with a heating central at the university campus

π compression chiller located on the roofπ Two air handling units, one of them with heat recoveryπ hot water supply by small electrical boilers

Demonstration Building | Informatic Systems Milan | Page 1

deMOnstratiOn BUilding: infOrMatic sYsteMs dePartMent, Mil an ( i )

| MUlti PUrPOse BUilding stUttgart | district hOsPital hagenOw | MinistrY düsseldOrf | KreUzgeBäUde essen | state treasUrY helsinKi | hUt engineering dePartMent esPOO | aUrOra 2 JOensUU | senate headqUarters helsinKi | infOrMatic sYsteMs Mil an | lectUre halls Mil an

electrOnics dePartMent Mil an | dUKa hOUse gOthenBUrg | nOrdstaden gOthenBUrg

renovation of the ventilation system achieves 4 % of savings

The amount of air change compared to the needs is higher than what is necessary. Moreover the energy recovery is only one of the air handling unit. The winter humidification is also disabled. Globally the building shows some deficiencies on the ventilation system. The two air handling units work in a different manner and the amount of supply air is not correct. Besides, some local discomfort can be highlighted which is related to the central air treatment. Those are linked to a false local calibration, which lead to overheating problem in some rooms (the most sun exposed) and sub-cooling of the basement rooms (computer room).

Overview

Kind of data acquisition Data logger (Energy Team)

Yearly energy cost 95,000 Euro

Cost for installation of data acquisition for minimal data set

32,000 Euro= 34 % of yearly energy cost

Estimated possible savings 4,000 Euro/year= 4 % of yearly energy cost

Simple pay back(of data acquisition only) 8 year

about Building eq

BuildingEQ is a project in the Intelligent Energy Europe Pro - gra mme of the European Commission. BuildingEQ aims at strength en ing the implementation of the EPBD (Energy Per-formance of Buildings Directive) by linking the certification process with commis sioning and optimisation of building performance. Within the scope of the project, methodologies and tools are to be devel oped that can be used for ongoing commissioning and optimisation of non-residential buildings using gathered data from the certification process according to the EPBD. The emphasis will be on feasibility and cost-effectiveness of energy reduction mea sures with regard to building practice. Main target groups are the industry for Facility and Energy Management, real estate owners, energy agencies and energy consultants.

www.Buildingeq.eu

imprint

Published by: fraunhofer institute for solar energy systems freiburg / germany, www.ise.fraunhofer.de

energieagentur regio freiburg gmbhfreiburg /germany, www.energieagentur­freiburg.deinfo @energieagentur­freiburg.de

design:

triolog – kommunikation mit energiefreiburg / germany, www.triolog­web.de

disclaimer

the sole responsibility for the content of this information lies with the authors. it does not necessarily reflect the opinion of the european communities. the european commission is not responsible for any use that may be made of the information contained.

results of the Building eq project

π energy saving potential in the operation of buildings 5 ­ 30 %π realisiation of these potentials with low or no investment costsπ Buildingeq methods and tools allow quick and cost efficient

detection of these potentialsπ Ongoing performance evaluation is prerequisite for energy

efficient operationπ consortium suggests amendment of ePBd with mandatory

performance monitoring

Supported by European Commissionwww.Buildingeq.eu

The consortium at a project meeting in Stuttgart

italY: Mil an

Project Partner

Politecnico di MilanoDipartimento di EnergiaProf. Livio Mazzarella Via Lambruschini, 420156 Milano/ ItaliaTelephone: +39-02-23991-3867

livio.mazzarella@polimi.itwww.energia.polimi.it

Building Owner

Politecnico di Milano Piazza Leonardo da Vinci 3220133 Milano/ Italia

www.polimi.it

result of certificate

According to the Building Performance Certificate (2007), the specific need of primary energy for the winter heating is equal to 83.4 kWh/m3·a (Asset Rating). This is mainly due to the thermal characteristics of the envelope according to the construction stan-dard of the sixties (construction year, 1961), without insulation on the walls and on the roof.Improvement can be obtained acting on the control system, especially for comfort improvement, then just one of the two air handling units have an air-to-air heat recovery. The domestic hot water consumption must be not taken in account during the asset rating calculation, because the usage is very poor.

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analysis of Measured data

Graph I shows the daily average of the electricity power in corre-lation to the external temperature. It can be noticed that there is no separation between the power needed during weekends (base load) and during workdays, as usual for non residential buildings (black lines). Graph II shows the relation between the cooling power and the external temperature. As usual in buildings with a weekly usage, the regression lines have a significantly different pent (black lines). The dispersion of the dots below and above the lines indicates that the system regulation could be improved.

Analyzing the indoor air temperature of different zones, a seminar room, an office and a computer room, a deficient control of the internal temperature could be noticed. Although the se-minar room has a comfortable temperature, comprised between 24 °C and 26 °C (graph III, red line), the PhD Office (graph IV) shows a significant overwarming, whereas the lecture room/computer room is overcooled (graph V). The same information is shown with carpet plot and time series plot in order to show how the information can be transmitted using different approaches.

aPr 09 MaY 09 JUn 09

vi. Outdoor air temperature

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iv. indoor temperature Phd office

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v. indoor temperature lecture room

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actual situation of the italian energy certification process

In Italy the energy performance certificate is implemented on a regional level up to now. Besides the national legislation, eight regions and autonomous provinces published their own laws and procedure. Italy does not provide pro cedural instructions for the operational rating OR method. The various procedures which are all currently valid cause a great deal of con- fusion among energy experts as well as building owners. This problem is then intensified by the economic incentives e.g. tax incentives that use the energy performance certificate as a basis. Nevertheless a good impulse on energy efficiency and renewable systems have been given to the market.

National certificate Lombardia certificate

Overview saving potentials

d e s c r i P t i O n O f s a v i n g s i n f l U e n c e

h e a t i n g a n d c l i M a t i z a t i O n s Y s t e M s

Improving the control system of heating, often a consumption is noticeable during the night

Increasing the system efficiency

The computer room is constantly air-conditioned, even when not used, and thus overcooled. Improve the local control

Increasing comfort and heat losses reduction

v e n t i l a t i O n a n d a i r h a n d l i n g U n i t s

Reduction of the excess of air change ratio (30 %), according with the hygienic requirements

Energy savings on ventilation needs (about 25 %)

Realization of VAV system, via update of fans and control system Energy savings on ventilation needs (about 20 - 30 %)

Installation of heat recovery air-to-air heat exchanger on air handling units (AHU)

Energy savings on ventilation needs (about 10 %)

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i. daily consumption data electricity

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ii. daily consumption data district cooling

Outdoor air temperature Outdoor air temperature

no data

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no data

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