An inclusive peer-to-peer approach to involve EU CONURBations and wide areas in participating to the CovenANT of Mayors

1
An inclusive peer-to-peer approach to involve EU
CONURBations and wide areas in participating to
the CovenANT of Mayors
New opportunities for buildings efficiency
2
Why buildings need heat and how they lose it?
To keep warm the air inside the building (usually
at 20 C) its necessary an amount of energy from
30 kWh/m2 year (the best efficiency actually
available) to 250 kWh/m2year (the worst
one). Obviously, it depend from external
temperature and solar radiation
3
Building Energy Efficiency some principles
From fuel to warm there are four steps of energy
transformation and energy dissipation
4
Energy saving options building envelope Heat
losses can be reduced with a better wall
insulation
5
Energy saving options heating plant Improving
efficiency of heat generator, regulation and
emission
6
Energy saving options heating plant Improving
efficiency of heat generator, regulation and
emission

• Condensing boiler with high temperature systems
  too 5-7
• Thermostatic valves easy and cheap intervention
  which provide at least 5 of energy saving
• Regulation temperature control for each room
• Emission low temperature emission system

7
How to obtain data energy audit
INTRODUCTION The objective of an energy
audit is to identify economical energy/cost
saving measures that do not adversely affect
environmental comfort standard
8
Scope of an energy audit
Energy audit is a needed step in implementation
of any detailed and sizable energy efficiency
project. The major impetus behind an energy
audit is that the analysis of energy consumption
and identification of potential conservation
measures.
9
There are two basic types of audits

• walk-through audit with the aim to identify
  potential energy saving measure
• investment grade audit. Investment grade audit is
  also called feasibility audit. It may be a
  comprehensive audit that is intended to identify
  all energy efficiency opportunities or a more
  targeted audit which focuses on a specific piece
  of equipment or process, e.g. lighting, a boiler
  ..

10
First step of a walk through audit

• a meeting should be held with the appropriate
  personnel
• The purpose is to determine which of the systems,
  technologies, and equipment listed below actually
  applied and where focus your attention during the
  walk-through audit.

11
Second step of a walk through audit

• go through the checklist of questions in a guide
  that pertain to the building.
• good opportunity to discuss any concerns that the
  personnel may have with implementing the energy
  saving measures

12
Third step of a walk through audit

• tour the building with the appropriate personnel
  that are familiar with the various areas that you
  will be auditing.
• refer to a guide to ensure that you answer any
  remaining checklist questions.
• The back of each page can be used to record your
  observations, such as equipment nameplate data,
  gage readings, meter readings, and to make notes,
  such as areas that require further study

13
Investment grade audit

• Def IGA is a technical and economic analysis of
  potential energy saving projects in a facility
  that
• Provides information on current energy consuming
  equipment operations
• Identifies technically and economically feasible
  energy efficiency improvements for existing
  equipment, and
• Provides the customer with sufficient information
  to judge the technical and economic feasibility
  of the recommended projects.

14
Which data must be collected

• Heat generator
• Nominal power
• Year of contruction
• Working temperature
• Inside the building
• Envelope properties (thickness of the wall,
  characteristics of the bricks, insulation if
  present)
• Walls
• Floor
• roofs
• Windows charachteristics (number of glass sheets,
  frame, etc)
• Tipology of emission systems (radiators, low
  temperature systems,)
• Regulation technology (internal centralized
  switch, regulation for each rooms, external drill
  for heating temperature driving)
• Energy Bills!!

15
Energy saving options Case studies
Käthe Kollwitz School in Aachen (Germany). The
school, built in 1951 and extended in 1995, had
passed its prime. A comprehensive building
refurbishment was seen as the way to improve
classroom conditions significantly, while
reducing energy costs.
16
Energy saving options Case studies
17
Energy saving options Case studies

• With windows accounting for approximately 67 of
  the outer surface, the school's facade is
  generously glazed.
• The exterior walls consist of a single layer of
  36.5 cm and 49 cm bricks, partly implemented as
  exposed brickwork on the outside, while the
  inside is plastered.
• In the radiator niche areas, the walls are only
  14 cm thick.

18
Refurbishment concept

• During refurbishment, the combination of two
  different facade structures was retained, and
  interpreted in a modern way. Now, areas with a
  thermal insulation composite system alternate
  with facade sections made of hung brick elements.
  Each has 12 cm-thick insulation.
• Thermally insulating glazing with frames made of
  wood and aluminium replaces the original
  single-pane wooden windows.
• The roof was insulated with 20 cm-thick cellulose
  fill.
• Parts of the cellar walls were insulated on the
  inside in areas with interior temperatures of
  20C.
• Partly for construction-related reasons, and
  partly due to cost benefit considerations, some
  thermal bridges were also consciously accepted
  for example, the base remained uninsulated, and
  no changes were made to the 4-to-5 cm-thick
  thermal insulation in the areas with no cellar.

19
Energy concept

• It was possible to convert the heat supply to
  remote heating. Already in the first construction
  stage, the entire building was connected to
  remote heating based on combined heat and power
  generation.
• Heating circuit distributors, pump technology,
  and the centralised control technology were
  renewed.
• Heating circuit distributors, pump technology,
  and the centralised control technology were
  renewed.
• The piping network was converted from a single
  pipe, to a two pipe system. In so doing, it was
  possible to continue using most of the old pipes.
  Approximately 40 percent of the ribbed radiators
  could then be removed due to the reduced heating
  requirement.

20
Energy concept

• Ventilation originally, only the kitchens were
  equipped with a ventilation system. During
  refurbishment, ventilation systems were installed
  in all classrooms, whereby the system, control
  method, and heat recovery differ between the
  various construction stages. This now enables a
  comparison of the different systems.

21
Energy concept

• Lighting much of the lighting system was out of
  date. Not able reach the light level required by
  the German industry standard DIN 5035.
• Solution mirror louvres with electronic dimmable
  ballasts, most of which are controlled in a
  daylight dependant manner.

22
Performance
In total, the refurbishment lowered the end
energy requirement for room heating, water
heating, and ventilation by 65. Measurements
taken during short periods in several classrooms
showed CO2 concentrations of up to 5,000 ppm
where only window ventilation was used. Where
mechanical ventilation was used, at just
16-17m³/h per person, in conjunction with quick
ventilation via all windows during breaks, CO2
content of 1,500 ppm (the DIN 1946-2 threshold
value) was never exceeded.
Construction costs and profitability The
refurbishment costs amounted to approximately 2.8
million euros.
23
Key Energy data
24
Economics
Refurbishment costs in /m2
Refurbishment costs (over all) 316
Exterior wall 44
Windows and doors 87
Building services equipment 83
Planning costs 62
Other building costs 16
25
Romano Selva Sogesca srl www.sogesca.it