European Territorial Cooperation Objective CENTRAL EUROPE Programme. GA Nr. 3CE302P3. CoP

Transcription

1 European Territorial Cooperation Objective CENTRAL EUROPE Programme GA Nr. 3CE302P3 CoP Deliverable No. CoP D3.4.5 Deliverable Title [Pilot Action Province of Turin site n 4 Collegno] Dissemination level [Public] Status [Final] Issue date 21/05/2014

2 Author(s) WP Lead Partner [Stefano DOTTA] (Environment Park) [Sergio RAVERA] (Environment Park) [Province of Ravenna] Pag 2

3 Executive summary Context and objective To fulfill an objective of cutting European emissions, the Cities on Power European project have been settled. The work package 3 aims are to promote the correct use of renewable energy in urban areas through action of planning, involvement of local actors and technical analysis. Studies were effected for four public buildings chosen within this context in the region Piedmont. About the building In this report are presented the methodology followed and the results obtained for the study of Allende, a leisure centre located in the city of Collegno, in the province of Torino. The building was chosen because it presents many problems of energy management. Methodology The methodology is divided into the following parts: - energy monitoring - results analysis - model calibration The study aims to define an envelope model extremely realist and accurate of the building in order to then be able to model the solutions proposed and validate them. To establish the model, an experimental monitoring was effected. A lot of data was collected on the building, through the use of monitoring devices such as an infrared camera or a heat flow meter. The model is validated thanks to the consumption bills of the previous years. The monitoring consisted in: Spot measurements of envelope components Monitoring of the energy and environmental quantities at long-term Spot measurements of environmental performance Building type and scope measurements are all listed in the following table: Scope of measurements - heat consumption, - electricity consumption - indoor climate parameters: o temperature o relative humidity - envelope performances Type of measurements - analysis of consumption bills - meteorological data (local station) - infrared thermal camera - infrared thermometer - meter thick glass The experimental survey was preceded by a geometric, architectural and plant survey, collecting data useful for highlighting criticalities. The collected data were processed in order to identify the main problems and the related interventions which can be adopted. Through the calibration of the calculation model, the solutions identified were then simulated and the results obtained have been highlighted with the retrofit solutions in terms of both energy and economic savings. Pag 3

4 Results The results are based on the experimental monitoring carried out that is explained on the previous paragraph. Environmental aspects (internal temperature and relative humidity time profiles) are analyzed in the results, permitting to assess the building thermal comfort. The energy point of view is also evaluated thanks to the monitoring carried out and the data collected. The confrontation between the reality (consumption bills) and the model, established thanks to all the data collected during the building audit, has permitted to get a precise and accurate model. This model was first established through a theoretical calculation based on references data, too far away from the reality observed on the field. The iterative confrontation between the parameters collected and the reality has allowed to get to the model calibrated validation. Conclusion The results obtained in this study are satisfying because they allow to calibrate the model. They also permit to identify the main criticalities of the building that can enable later to find the best solutions to limit the building energy losses. The usual approach, based on the standard data and the theoretical software calculations, is often really far away from reality. To achieve a study that is realistic and allow to find solutions adapted to decrease the energy consumption of the building, field studies are indispensables. The model thus calibrated, the next phase will consist in the solutions identification. The different solution scenarios will be judged, according to their pertinence, thanks to the model. Pag 4

5 Contents Executive summary... 3 Context and objective... 3 About the building... 3 Methodology... 3 Results... 4 Conclusion... 4 Contents Introduction Context and objective General overview of the building Other building characteristics Methodology Spot measurements of envelope components Thermograph analysis Glass thickness measurement Software calibration Specific thermal bridges definition Model definition Results Building s envelope Incidence as a percentage of individual elements on the total dispersion Walls and surfaces characterization Envelope criticalities Energy consumption analysis Building s consumption table Existing installations Connecting the model and data Conclusions Scenarios Thermal insulation coverage area BAR Analysis of costs and benefits Thermal insulation external walls, BAR area Analysis of costs and benefits Installing heaters area GYM Analysis of costs and benefits Thermal insulation roof area GYM Analysis of costs and benefits Pag 5

6 4.5 Global action BAR Global action GYM Analysis of costs and benefits using current hypothesis 2 times a week Cost and benefit analysis hypothesis future use 7 times a week Publics Incentives ( Conto termico ) Cost-benefit analysis Intervention total area BAR with public incentives Cost-benefit analysis Intervention total area GYM with public incentive Conclusions Pag 6

7 1 Introduction 1.1 Context and objective In Italy, 31 % electricity energy and 44 % thermal energy (combustible) are consumed in buildings. Cutting emissions is a worldwide issue today. To fulfill this objective, the Cities on Power European project have been settled. The work package 3 aims are to promote the correct use of renewable energy in urban areas through action of planning, involvement of local actors and technical analysis. In this report are presented the results of the study of one of the four public buildings chosen within this context in the region Piedmont, that is to say Allende, a leisure center located in the city of Collegno, in the province of Torino. 1.2 General overview of the building Allende is a leisure center located in the city of Collegno, in the province of Torino. In this building, measurements have been done and data have been collected thanks to analysis of consumption bills related to the energy consumptions of the building, to the meteorological data (local station) and to infrared thermal camera. Here are some photos of the leisure center: Figure 1.1 Collegno leisure centre photos Building main characteristics are listed in the following table: General overview Year of construction 1990 Typology of the building Leisure Centre Surface 700 Volume Construction method Prefabricated panels in concrete cement Heating system Boiler air heating Hot water Boiler Ventilation No PV/electric devices No Table 1.2 Collegno leisure centre general overview Pag 7

8 Here is a photo of the ground plan: Figure 1.2 Collegno leisure centre ground plan 1.3 Other building characteristics As a reminder, scope of the contract includes delivery, installation and commissioning of the measuring and recording system of the heat and electricity energy consumption, with the indoor and outdoor climate parameters of the leisure center. Therefore, some other data (climatic and geometric data) have also been collected and are summarized in the following tables: Climatic data of the place Altitude a.s.l. 302 m Degree K*day 2646 Climatic zone E Outside temperature project - 8 C Table 1.2 Collegno leisure centre climatic data Geometric data of the place NET plant surface 1119,00 m 2 Gross external surface 3270,17 m 2 Net volume 7586,82 m 3 Gross volume 8793,93 m 3 Ratio S/V 0,37 m -1 Net height 6,78 m Table 1.3 Collegno leisure centre geometric data Pag 8

9 2 Methodology The research activity, once the energy audit of the building in question was done, consisted in the identification of solutions for the environmental energy regeneration which were characterized thanks to an experimental analysis. The study finally led to the drafting of a document reporting the energy and environmental monitoring. The monitoring was conducted through different modes of importance and with different purposes: a) Spot measurements of envelope components, aiming at the thermal characterization of the building envelope for the calibration of the calculation model b) Monitoring of energy and environmental quantities over a long period though bills and data provided by the Piedmont Region and weather stations. The phase of experimental survey was preceded by a geometric, architectural and plant survey, collecting data useful for highlighting criticalities (such as consumption bills or the usage profile of the spaces). The collected data were processed in order to identify the main problems and the related interventions which can be adopted. Through the calibration of the calculation model, the solutions identified were then simulated and the results obtained have been highlighted with the retrofit solutions in terms of both energy and economic savings. The measurements have been done and the data collected thanks to analysis of consumption bills related to the energy consumptions of the building, to the meteorological data (local station) and to infrared thermal camera. Building type and scope measurements are all listed in the following table: Scope of measurements Type of measurements - heat consumption, - analysis of consumption bills - electricity consumption - indoor climate parameters: o temperature - meteorological data (local station) o relative humidity - infrared thermal camera - envelope performances - meter thick glass Table 2.1 Scope and type of measurements The methodology followed for this building is rather different than the ones effected usually. Some devices such as heat flow meter was not used, for example. In that case, the heat flow meter cannot be used because of the building particularity of using. As this device has to be used during a minimum of 72 hours to get right results, it was left behind. In fact, the building is used only for very short period because of its size (see internal building view below). The ventilation need is too important to keep the building open for a so long time period. Pag 9

10 Figure 2.2 Internal view of the building Furthermore, absolutely no coring was effected because of the extreme quality of the building documentation provided. The preciseness and the accurateness of the documentation has allowed to proceed to the building envelope reconstitution without using the usual tools. 2.1 Spot measurements of envelope components The measurements conducted are: - thermograph measurement through the use of an infrared camera (FLIR Serie) in order to identify the thermal bridges and to measure the internal surface temperatures relative to the thermal bridges. - glass thickness measurement through the use of a glass thickness tester (MERLIN Lazer type) in order to determine the windows insulation quality Pag 10

11 2.1.1 Thermograph analysis The thermal imaging camera (see opposite) is used to determine the insulation weak points. This camera is designed to register the heat waves radiated by the building. These ones varied according to the temperature. Thermograph uses the ability of devices to detect this radiations in infrared band. Thus, the different thermal bridges can be identified. Thanks to this device, immediate measurements can be done and furthermore, it is non invasive. But, it has to be noticed that the quality of the measurement depends on the outside conditions. Figure 2.2 Infrared camera The thermal bridges can be observed on the images captured by the camera (see below) for the north, northwest and west facades respectively. Figure 2.2 Thermograph pictures However, the photos taken by the camera are not enough to calculate the building consumption. They only identified the main insulation flows on a qualitative point of view. The thermal camera shows also only the temperature of the superficial cover. To complete this study, the documentation provided was used. Pag 11

12 2.1.2 Glass thickness measurement In order to get all the data concerning the building, a glass thickness tester is used (see apposite). It is designed to measure quickly and simply the thickness of the building glasses. The windows being usually one of the most responsible of energy losses, it is necessary to understand why. Figure 2.3 Glass thickness tester 2.2 Software calibration Specific thermal bridges definition Thanks to a software specialized in finite-elements calculation, named HEAT, the real heat transfer coefficients are calculated corresponding to the specific thermal bridges. The figure below presents the stretch of wall where a heat transfer coefficient was predicted. Figure 2.4 Heat simulation capture Pag 12

13 2.2.2 Model definition Finally, all the data collected are entered in an software which, basing on these experimental data and the real heat transfer coefficient calculated, is able to model the whole building and so on his behaviour. Therefore, the envelope building consumption is determined. Then, this number is compared with the consumption bill amount to evaluate his pertinence. If the numbers are closed, the model can be validated. With this parameters, the software can be considered as calibrated. That is to say, the envelope consumption can be forecast thanks to the software. The solutions proposed to decrease the energy consumption of the building (improvement of the insulation, add of solar panels, etc.) can now be tested to evaluate the ones which provide the greatest benefits. Pag 13

14 3 Results 3.1 Building s envelope Incidence as a percentage of individual elements on the total dispersion Thanks to all the data collected, the building losses distribution can be made, allowing to identify which building components consume the more energy. Below are presented the building losses rates: Walls Roofs Floors Thermal Bridges Windows Figure 3.1 Building losses distribution Insulation of external roof dispersant produce the most significant effects at the level of dispersion containment Walls and surfaces characterization Here are some views of the exterior walls: Figure 3.2 Exterior walls views Pag 14

15 On the table beside can be seen the walls 1 and 2 (located in the bar and in the dressing room) cross sections. Their thermal transmittance (or U- value) is detailed in red. As a reminder, the more the transmittance is increased, the more the building is poorly insulated. The different wall layers can be well identified here and their importance in the wall insulation can be understood. Table 3.1 Wall 1 and 2 cross sections On the table beside can be seen, the surfaces 1 (located in the bar and in the dressing room) and 2 (located in the playing field) cross sections. Table 3.2 Surface 1 and 2 cross sections Pag 15

16 Figure 3.3 Software capture The different building characteristics are reported in the software, which calculate the theoretical thermal transmittance coefficient ( U or Uw ). With the addition of the information concerning the thermal bridges and the building losses in general, the software is able to calculate the real thermal transmittance coefficient or average coefficient ( Umedia or Ug ) Envelope criticalities The main criticalities identified concerning the envelope are : - Discontinuity construction of the building envelope exterior - High volumetric expansion of the building - Presence of a large number of thermal bridges 3.2 Energy consumption analysis Building s consumption table The volume and height (almost 7 m) are not negligible here, and it is taken into consideration when the building analysis is done. The ventilation need is very important that is why a new solution has to be found to decrease the building energy consumption. The table below shows the building consumption. Pag 16

17 Consumi termici Mese (Nm 3 ) 1 ott nov dic gen feb mar apr mag giu lug ago set TOTALE Table 3.1 Heating consumption From the total consumption of the 12 months we get the natural gas consumption in a year: Nm 3 /anno. This value will be used to calibrate the model. Consumi elettrici Mese (kwh) 1 dic gen feb mar apr mag giu lug ago set ott nov TOTALE Table 3.2 Electricity consumption From the total consumption of the 12 months we obtain the electric energy consumption in a year equal to: kwh/year. The annual value of electric energy consumption is due to a power of bodies illuminants equal to 7 kw in the gym and 3 kw in Bar, besides the presence of the UTA (air handling units) which could not be traced back to the model it it to its electrical power. Pag 17

18 3.2.2 Existing installations The current installation used to heat the building is a furnace (see opposite). Yet, this system require a mixing rate sufficient of 3 to 5 volumes per hour (due to stratification phenomena) and an excellent isolation to limit heat losses, which is not the case here. The air is heated by convection and it is less efficient than heating by radiation. Furthermore, the need for ventilation increase the electricity consumption, which, as detailed before, is three more times important than the heat consumption itself. Figure 3.5 Furnace picture The main criticalities identified concerning the plant are : - Plant management to improve - Differences in the supply of heat between the different areas of the building - Non-existents datas on the UTA 3.3 Connecting the model and data Based on actual data collected ( bills of consumption, climate data and geometry data) and data developed monitored ( measurement results ), is defined as the building model. Its precision and accuracy depend on the use of data. In fact, every passage, the calculations were adjusted so as to correspond as closely as possible to the real data. To be more precise, the input parameters in the software are : grades K * day, temperatures inside actual use of the building and management of the installation time. The software initially carried a theoretical calculation which is not quite satisfactory, because it is too far from reality shows from the bills of consumption. The model is then calibrated by changing these different parameters based on the data of the bills of previous years. When the numbers are very similar, the model can be considered validated. To properly modelling is necessary to divide the building into 2 zones: zone and area GYM BAR. This requirement is due to a completely different use of the heating system. To calibrate the model, we followed as stated by the operator with respect to hours per week of use of the system : BAR AREA : 10 hours a day, 6 days a week. ZONE GYM : 5 hours of operation per day for 2 days a week. For zone BAR use of the system is continuous so you can use a static model of computation. Below is a screen with the result obtained by heating the BAR area. Pag 18

19 Figure 3.6 Screenshot of the software area BAR Which results in an annual consumption of natural gas by Nm 3 /anno For the area GYM you need to implement a dynamic model of computation, because the utilization is purely discontinuous. The model is based on the following assumptions: Renewal of air m 3 / h (calculated on the air changes according to the standard maximum ca-compliance of the gym). UTA always function with renewal equal to 4000 m 3 / h Presence of nell'uta recovery with real average return of 40% The model gives as result an annual methane Nm 3 /anno To estimate the consumption of methane due to the water heater and the use of gas for cooking, they are used actual consumption reported in the bills during periods when you are not using the heating. Such consumption is attributable entirely to domestic gas and sanitary hot water. Months Effective consumption [Nm 3 ] sect aug july june may By making a monthly average and multiplying it by 12 months, we get the estimated consumption per share: hot water and cooking Nm3/anno Pag 19

20 Summing up the results we obtain an annual consumption of natural gas of Nm3/anno, which compared with the actual consumption we get an error of 4%, this value allows us to validate the model. 3.4 Conclusions The project aims to study the criticalities on an energy point of view of the building realized in the 80 s (prefabricated panels). Another objective was to identify the best strategy to decrease the building energy consumption. Understand the building operation is very important to renew this study and results for other buildings. The understanding is on an energy point of view, that is to say, focusing on the installations and envelope. However, as a complex system is studied, with a lot of difficult parameters to forecast, each study has to be treated differently. The usual approach to carry out this kind of study is to establish a model based on simplified variables, that are the standard variables. But, in real conditions, this variables cannot be applied. In effect, the real variables are affected by the climatic data which are different, for example or the building management modalities are often far away from the references of an unitary model. The different factors that have an influence on the building energy consumption can be summed up below: - extern climatic parameters - envelope characteristics - installations characteristics - installations management - users behavior To carry out a realistic energy study, these parameters have to be collected on the field. To perform a complete study, it has to be based on basics information: the building characteristics (envelope, walls and windows) and the installations characteristics (air-conditioning system, domestic hot water production, lighting and electricity use). To have a better understanding of the building, projects documents are used and field studies are achieved. The mains criticalities indentified during this study are, concerning the building envelope: - Discontinuity construction of the building envelope exterior - High volumetric expansion of the building - Presence of a large number of thermal bridges concerning the plant: - Plant management to improve - Differences in the supply of heat between the different areas of the building To conclude, the environmental issue of this building concerns the thermal comfort. The huge volume never allow the internal temperature to reach the 20 C (temperature admitted as the temperature of welfare). The ventilators are too high to success in warming the air at ground level The next phase will concern the solution proposal. To that purpose, a lot of different scenarios will be tested through the model established and they will be then validated according to their benefits. Pag 20

21 4 Scenarios From the models of the status quo described above were implemented 4 possible actions, to verify the technical feasibility of the economy. The interventions are hypothesized the following: o Thermal insulation coverage area BAR o Thermal insulation through walls BAR coat area o Install unit heaters area GYM o Thermal insulation coverage area GYM 4.1 Thermal insulation coverage area BAR In the state of that coverage has a thermal transmittance of 0,621 W/m2K, and is responsible of 16,5% of the total leakage area of the housing BAR. It is hypothesized to isolate coverage through EPS of thickness equal to 20 cm; this action leads to the thermal transmittance W/m2K which allows you to drop to 4,8% losses attributable to the global envelope BAR coverage. The stratigraphy complete, pre-and post-intervention, are listed below: Description of the structure: Roof bar and changing BEFORE ACTION Heat transmission rate 0,604 W/m 2 K Thickness 284 mm Outdoor design temperature -8,0 C Permeance 0, kg/sm 2 Pa Surface mass (with plaster) 451 kg/m 2 Surface mass (without plaster) 415 kg/m 2 Periodic heat transmission rate 0,106 W/m 2 K Attenuation factor 0,176 - Thermal wave shift -9,5 h Stratigraphy: N. Description of the stratigraphy s Cond. R M.V. C.T. R.V. - External surface resistance - - 0, Still 2,00 52,000 0, , Polyurethane 40,00 0,035 1, , Waterproofing with bitumen 2,00 0,170 0, , Lean concrete subfloor 40,00 0,900 0, , Floor filler blocks 180,00 0,720 0, , Cement and sand coat 20,00 1,000 0, , Internal surface resistance - - 0, Pag 21

22 Description of the structure: Roof bar and changing AFTER ACTION Heat transmission rate 0,156 W/m 2 K Thickness 444 mm Outdoor design temperature -8,0 C Permeance 0, kg/sm 2 Pa Surface mass (with plaster) 460 kg/m 2 Surface mass (without plaster) 424 kg/m 2 Periodic heat transmission rate 0,019 W/m 2 K Attenuation factor 0,124 - Thermal wave shift -13,0 h Stratigraphy: N. Description of the stratigraphy s Cond. R M.V. C.T. R.V. - External surface resistance - - 0, Still 2,00 52,000 0, , Expanded polystyrene 200,00 0,034 5, , Waterproofing with bitumen 2,00 0,170 0, , Lean concrete subfloor 40,00 0,900 0, , Floor filler blocks 180,00 0,720 0, , Cement and sand coat 20,00 1,000 0, , Internal surface resistance - - 0, Symbols legends s Thickness mm Cond. Conduttività termica, comprensiva di eventuale maggiorazione W/mK R Thermal resistance m 2 K/W M.V. Volumic mass kg/m 3 C.T. Thermical specific capacity kj/kgk R.V. Vapour wave factor - The results obtained with the model are the following: Analysis of costs and benefits. In order to verify the technical-economic feasibility we need to analyze the investment costs with the annual cost savings due to a lower consumption of methane. For this analysis, we consider the cost of natural gas equal to 0.7 /Nm 3 Resulting in an annual saving of 515 For the evaluation of the investment is considered to be a comprehensive cost 60 /m 2 : for the EPS insulation, cover a total area of 205 m 2 : Considering 10% VAT, planning costs to 10%, VAT at 22% compared to the costs of design, we obtain: Investment of Pag 22

23 We now report the results obtained for the calculation of the Net Present Value (NPV) and Internal Rate of Return (IRR). 4.2 Thermal insulation external walls, BAR area To decrease the thermal losses of the walls it is thought to realize a thermal insulation in the external walls with polystyrene EPS (thickness of 15 cm). Also, since the evening use of the structure, it is also necessary to isolate the masonry composed of glass block as it is attributable to 11% of the total dispersion zone BAR. The stratigraphy complete, pre-and post-intervention, are listed below: Description of the structure: Walls block BEFORE ACTION Heat transmission rate 0,512 W/m 2 K Thickness 301 mm Outdoor design temperature -8,0 C Permeance 0, kg/sm 2 Pa Surface mass (with plaster) 173 kg/m 2 Surface mass (without plaster) 173 kg/m 2 Periodic heat transmission rate 0,257 W/m 2 K Attenuation factor 0,502 - Thermal wave shift -7,1 h Stratigraphy: N. Description of the stratigraphy s Cond. R M.V. C.T. R.V. - Internal surface resistance - - 0, Perforated block 120,00 0,429 0, , Air gap Av<500 mm²/m 60,00 0,333 0, Aluminum foil vapor barrier ( mm) 1,00 220,000 0, , Expanded polystyrene (UNI 7819) 40,00 0,040 1, , Perforated block 80,00 0,288 0, , External surface resistance - - 0, Description of the structure: Walls block AFTER ACTION Heat transmission rate 0,147 W/m 2 K Thickness 461 mm Outdoor design temperature -8,0 C Permeance 0, kg/sm 2 Pa Surface mass (with plaster) 192 kg/m 2 Surface mass (without plaster) 179 kg/m 2 Periodic heat transmission rate 0,018 W/m 2 K Attenuation factor 0,121 - Thermal wave shift -12,7 h Pag 23

24 Stratigraphy: N. Description of the stratigraphy s Cond. R M.V. C.T. R.V. - Internal surface resistance - - 0, Perforated block 120,00 0,429 0, , Air gap Av<500 mm²/m 60,00 0,333 0, Aluminum foil vapor barrier ( mm) 1,00 220,000 0, , Expanded polystyrene (UNI 7819) 40,00 0,040 1, , Perforated block 80,00 0,288 0, , Polystyrene EPS 150,00 0,031 4, , Plastic plaster 10,00 0,300 0, , External surface resistance - - 0, Description of the structure: Glass block BEFORE ACTION Heat transmission rate 2,540 W/m 2 K Thickness 80 mm Outdoor design temperature -8,0 C Permeance 0, kg/sm 2 Pa Surface mass (with plaster) 80 kg/m 2 Surface mass (without plaster) 80 kg/m 2 Periodic heat transmission rate 2,405 W/m 2 K Attenuation factor 0,947 - Thermal wave shift -1,6 h Stratigraphy: N. Description of the stratigraphy s Cond. R M.V. C.T. R.V. - Internal surface resistance - - 0, Glass block (80 mm) 80,00 0,450 0, , External surface resistance - - 0, Description of the structure: Glass block AFTER ACTION Heat transmission rate 0,190 W/m 2 K Thickness 240 mm Outdoor design temperature -8,0 C Permeance 0, kg/sm 2 Pa Surface mass (with plaster) 99 kg/m 2 Surface mass (without plaster) 86 kg/m 2 Periodic heat transmission rate 0,129 W/m 2 K Attenuation factor 0,677 - Thermal wave shift -5,7 h Stratigraphy: N. Description of the stratigraphy s Cond. R M.V. C.T. R.V. - Internal surface resistance - - 0, Glass block (80 mm) 80,00 0,450 0, , Polystyrene EPS 150,00 0,031 4, , Plastic plaster 10,00 0,300 0, , External surface resistance - - 0, Pag 24

25 Symbols legends s Thickness mm Cond. Conduttività termica, comprensiva di eventuale maggiorazione W/mK R Thermal resistance m 2 K/W M.V. Volumic mass kg/m 3 C.T. Thermical specific capacity kj/kgk R.V. Vapour wave factor - The results obtained with the model are the following: Analysis of costs and benefits. In order to verify the technical-economic feasibility we need to analyze the investment costs with the annual cost savings due to a lower consumption of methane. For this analysis, we consider the cost of natural gas equal to 0,7 /Nm 3 Resulting in an annual saving of For the evaluation of the investment is considered to be a comprehensive cost 90 /m 2 for the EPS insulation, the walls have a total area of m 2 Considering 10% VAT, planning costs to 10%, VAT at 22% compared to the costs of design, we obtain: Investment of We now report the results obtained for the calculation of the Net Present Value (NPV) and Internal Rate of Return (IRR). Pag 25

26 4.3 Installing heaters area GYM The installation of unit heaters is absolutely necessary given the absolute inadequacy of the ventilation system exists. At present, the system does not guarantee a fast heating of the area, very important in this situation because of the use strongly intermittent. The reasons are certainly many such as: the location at an altitude of 6 meters of hot air outlet grills, the likely mode operation UTA maximum renewal of air. The manager of the gym told us that the use of the same is done with a maximum of a few dozen people, and with an average of 10 people, so the solution is the use of heaters that allow rapid heating of the area, while the existing UTA may be used only for the exchange of air when there will be greater turnout. The water heaters are supplied with the circuit from the boiler which at present is connected to UTA. From the analysis carried the thermal power of the heaters to be installed will be equal to : 150KW in the case where the roof remains in the current state, 60kW in the case where the roof is isolated. The results obtained with the model are the following : Analysis of costs and benefits. In order to verify the technical-economic feasibility we need to analyze the investment costs with the annual cost savings due to a lower consumption of methane and electricity. The basic assumptions of this analysis regarding the state of affairs of the UTA where you cannot find any data, and are as follows: Pag 26

27 o Renewal of air 4000 m 3 /h ( calculated on the air changes according to the standard maximum ca -compliance of the gym ). o UTA always function with renewal equal to 4000 m 3 /h o Presence in the UTA of a real recovery with average yield of 40% o Electrical power of 7 kw UTA For this analysis, we consider the cost of natural gas equal to 0.7 /Nm 3 and the cost of electricity equal to 0,2 /kwh. Resulting in an annual saving of 667 For the evaluation of the investment is considered a cost of 6350 inclusive Considering 10% VAT, planning costs to 10%, VAT at 22% compared to the costs of design, we obtain: Investment of for the heaters of total thermal power of 150 kw. As for the heaters 60 kw of power, to be used only with the insulation of the roof, the total investment cost amounted to We now report the results obtained for the calculation of the Net Present Value (NPV) and Internal Rate of Return (IRR ) in the case of installation of the heaters 150 kw. Considering the use of the gym 2 times a week for 5 hours, as stated by the manager. Pag 27

28 4.4 Thermal insulation roof area GYM In the state of that coverage has a thermal transmittance of 3,337 W/ m 2 K, and is responsible of 66% of the total dispersion envelope gym area. It is hypothesized to isolate coverage through polystyrene EPS of thickness equal to 20 cm; this action leads to the thermal transmittance 0,165 W/m2K which allows you to reduce up to 9% of global losses attributable to the housing cover. The stratigraphy complete, pre-and post-intervention, are listed below: Description of the structure: Roof GYM BEFORE ACTION Heat transmission rate 3,337 W/m 2 K Thickness 104 mm Outdoor design temperature -8,0 C Permeance 1, kg/sm 2 Pa Surface mass (with plaster) 162 kg/m 2 Surface mass (without plaster) 162 kg/m 2 Periodic heat transmission rate 2,760 W/m 2 K Attenuation factor 0,903 - Thermal wave shift -2,4 h Stratigraphy: N. Description of the stratigraphy s Cond. R M.V. C.T. R.V. - External surface resistance - - 0, Still 2,00 52, ,45-2 Air gap Av=900 mm²/m 40, Waterproofing with bitumen 2,00 0, , Reinforced concrete floor 60,00 2, , Internal surface resistance - - 0, Description of the structure: Roof GYM AFTER ACTION Heat transmission rate 0,164 W/m 2 K Thickness 264 mm Outdoor design temperature -8,0 C Permeance 0, kg/sm 2 Pa Surface mass (with plaster) 172 kg/m 2 Surface mass (without plaster) 172 kg/m 2 Periodic heat transmission rate 0,097 W/m 2 K Attenuation factor 0,592 - Thermal wave shift -6,7 h Stratigraphy: N. Description of the stratigraphy s Cond. R M.V. C.T. R.V. - External surface resistance - - 0, Still 2,00 52,000 0, , Expanded polystyrene 200,00 0,034 5, , Waterproofing with bitumen 2,00 0,170 0, , Reinforced concrete floor 60,00 2,150 0, , Internal surface resistance - - 0, Pag 28

29 Symbols legends s Thickness mm Cond. Conduttività termica, comprensiva di eventuale maggiorazione W/mK R Thermal resistance m 2 K/W M.V. Volumic mass kg/m 3 C.T. Thermical specific capacity kj/kgk R.V. Vapour wave factor - The results obtained with the model are the following: Analysis of costs and benefits. In order to verify the technical-economic feasibility we need to analyze the investment costs with the annual cost savings due to a lower consumption of methane, always under the assumption of use of the gym for only 2 days a week. For this analysis, we consider the cost of natural gas equal to 0,7 /Nm 3 Resulting in an annual saving of For the evaluation of the investment is considered to be a comprehensive cost 60 /m 2 for the EPS insulation, cover a total area of 880 m 2 Considering 10% VAT, planning costs to 10%, VAT at 22% compared to the costs of design, we obtain: Investment of We now report the results obtained for the calculation of the Net Present Value (NPV) and Internal Rate of Return (IRR). Considering the use of the gym 2 times a week for 5 hours, as stated by the manager. Pag 29

30 Pag 30

31 4.5 Global action BAR For total intervention is the set of interventions insulation external walls, this scenario has also been implemented in the model with the following results: Getting an annual saving of Faced with a total investment: We now report the results obtained for the calculation of the Net Present Value (NPV) and Internal Rate of Return (IRR). From the results obtained it is evident that an action on the BAR area is not economically advantageous. Pag 31

32 4.6 Global action GYM For total intervention is the set of interventions insulation of the roof and installation of heaters, this scenario has also been implemented in the model obtained taking the following results: To make an assessment of the costs and benefits accurately, two possibilities were envisaged scenarios of future use. A first scenario, which corresponds to the current state, in which the gym is underutilized, another scenario where the gym is used for seven times a week. These considerations have arisen from that stated by the manager, who said that at present cannot use the gym for more than 2 times a week, as they do not fall in costs, but the costs were lower could open more regularly. With the proposed interventions, the average cost of power plant per day (5 hours) would pass by: Analysis of costs and benefits using current hypothesis 2 times a week We now bring the results obtained for the calculation of the Net Present Value (NPV) and Internal Rate of Return (IRR). Pag 32

33 4.6.2 Cost and benefit analysis hypothesis future use 7 times a week We now report the results obtained for the calculation of the Net Present Value (NPV) and Internal Rate of Return (IRR). Pag 33

34 5 Publics Incentives ( Conto termico ) The Conto termico is the name of the account DECREE on December 28, 2012: Incentivetion of thermal energy production from renewable sources and energy efficiency small interventions. The decree set aside a total of EUR 200 million for energy improvements made by government. The incentives are obtainable in the following table extracted from the decree: To obtain the incentives, which is equivalent to 40% of the costs it is necessary to carry out the work as soon as possible. It is now proposed an economic analysis by obtaining the incentives in the cases: Global action zone BAR Global action zone GYM 5.1 Cost-benefit analysis Intervention total area BAR with public incentives The intervention of the bar area includes the total isolation of the cover and coat the walls. Through profit or heat you get a total incentive equal to 40% of the estimated expenditure for the bar area of approximately This incentive will be extended over five years after the implementation of the interventions. Pag 34

35 We now report the results obtained for the calculation of the Net Present Value (NPV) and Internal Rate of Return (IRR). Pag 35

36 5.2 Cost-benefit analysis Intervention total area GYM with public incentive The intervention of the total gym area includes the insulation of the roof and the installation of the heaters. Through profit or heat you get a total incentive equal to 40% of the estimated expenditure for the isolation of the gym area coverage of about This incentive will be extended over five years after the implementation of the interventions. We now report the results obtained for the calculation of the Net Present Value (NPV) and Internal Rate of Return (IRR), considering the use of the gym 7 times a week for 5 hours a day. Pag 36

37 6 Conclusions Without publics incentives The analysis highlights how the costs and benefits for the BAR area there is a return on investment if not in small part to the intervention of the insulation of the external walls. As regards the area GYM, with a use of the same for only 2 days in the week, there is no economic interest in carrying out such interventions. However, being at the gym today largely untapped, providing a greater use return times for each intervention could be reduced considerably. For example, if we assume a five hours of use per day, seven days a week, the discounted payback is 9 years old. In conclusion it can be stated that any intervention that will be made to the current state of use of the gym cannot be justified from an economic return due to energy savings generated, while it is desirable that an improvement of the efficiency of the system could allow the operator to increase the hours of opening and therefore generate a reduction of the time of return. With publics incentives By obtaining the incentives of the thermal account there is a modest economic return to the bar area, and a substantial economic return to action in the gym. For the above reasons it is desirable to fast action in the gym, in order to award incentives, and in this way make the structure very competitive with low cost of ownership, otherwise it will be unusable with time during the winter. Pag 37