ENERGY SAVING MEASURE #1: RIESI
The retrofitting development that involved the 51 dwelling at Via Riesi in Orbassano gave ATC the possibility to put in action an innovative way of providing energy saving in social housing firstly by providing usable ICT-based services for Resource Management and Resource Awareness directly to tenants, secondly by providing effective ICT monitoring and controlling of heating consumption.
The application of a highly innovative system – ADAPTERM – showed a significant improvement of the energy saving and suggested the possibility of using the same control system in other developments in order to help reducing consumption peaks and optimises the timing of domestic consumption. It is very relevant to underline that an optimised timing of consumption can reduce generation capacity requirements and, with appropriate tariffs, tenant costs.
The feasibility and efficiency of this type of retrofitting was part of the development of BECA project from a technical point of view and it was rightly evaluated through AFTER providing ATC Torino with a synergic image between application of retrofitting and consequently evaluation and monitoring of results.
This approach provides ATC Torino with a structured protocol allowing the future possibility to apply the correct retrofitting measure to a large part of the real estate granting cost reduction, efficiency and control, needless to add that the strategic approach of AFTER constitute an asset for ATC of great relevance for the future. The new heating system based on three condensing boilers (power: 115 kW each) and a smart metering system joined to the tenants awareness measures put in place were selected in order to accomplish with the requirement of promoting energy efficiency in social housing that ATC Torino has been pursuing as a long term strategy.
The economic gain will be further demonstrated since tenants have the concrete possibility to properly monitor their consumption. In order to fix a firm figure, it is already possible to demonstrate that starting from an initial investment of circa 120 Euro per dwelling the return is visible in terms of energy saving since the ADAPTERM was installed.
Comparing the consumption of gas for the winter seasons 2012-2013 and 2013-2014 there was a saving of 3,925.00 cubic metres, since the price for gas is around 0,610 Euro per cubic meter, the saving was 2.394,25 Euro the saving per dwelling has been around 25 Euro per dwelling per year.
The economic effect of the above is also quantifiable as tenants satisfaction and greater willingness of the residents to pay for their bills and their rent fees; this for ATC is to be considered as a significant gain for ATC aside with the indubitable fact that to maintain a well-run and up to date system is cost efficient also in terms of maintenance.
The energy saving management in Orbassano was accompanied by a tenant’s awareness campaign and the implementation of dedicated software that allows the tenants to check daily for their consumption.
ENERGY SAVING MEASURE #2: PASSONI
The Energy Saving Measure includes in the AFTER Project for the building PASSONI is the substitution of the two old twin boilers (power: 98 kW each) with one new condensing boiler (92 kW). This new boiler (as the old ones) serves only the heating system; tenants have single boilers in their apartments (electrical, most of the time) to produce DHW.
The initial investment was about 36 600 EUR. After the replacement of the boiler the energy savings prove to be significant. From the consumption of 133 MWh in the year before the measure was implemented, savings in the range of 27-50 MWh per year were measured, thus showing the eligibility of the conducted measure.
The initial proposal to be implemented at via Passoni case study, in order to improve the performance of the new boiler, was to obliterate completely the heat exchanger. This solution it was not in the end feasible due to warranty issues since ATC signed a 10 years contract with the supplier who grants the plant only if equipped with an heat
exchanger which prevents problems and keeps the boiler in good condition.
The energy saving measure implemented as a consequence for the above, and considering that the heat exchanger is an element responsible for heat loss it was installed an insulation cap for the heat exchanger. This proposal was accepted and implemented as it was considered a good compromise between the need to keep the boiler warranty and the need to improve heating system efficiency.
The optimized ESM introduced at via Passoni represents a cost efficient solution for energy saving that ATC will definitely use in similar situation in order to maximize energy saving with modest expenses. Total cumulative investment amounts to 1.275,00 €, where the highest cost in ESM represents the investment in insulation of the heating cap (250 EUR) and the implementation of data loggers to measure the indoor and outdoor temperatures for the building.
By taking into account only the period from November – April (year 2012 and 2013) the average energy savings were 3,84 % that is in the expected range (leading to 3,65MWh of savings). Energy savings were recorder in December, January, February and March – in the core of the heating season. The optimizations solution resulted in 3-12% of energy savings in those months, according to the national HDD (20-15). There is no sign of improvement in transitional months April and October and November as well. No specific reason was given, why consumption was so much higher than the year before, when the optimization solution was not yet implemented. The results of measured indoor temperatures and relative humidity in three apartments show that the tenants maintained relatively high indoor temperatures, e.g. apartment’s 2 indoor average temperatures is around 24°C, apartment’s 3 average temperatures is around 23°C. These indoor temperatures were recorded in October, when HDD is the lowest of all months in the heating season. Higher consumption can as well be attributed to the user behaviour.
ENERGY SAVING MEASURE #3: PICCO
The Via Picco building was renovated between 2008 and 2010 providing a substantial substitution of the main part of the envelope. An external wall insulation system was applied in order to provide thermal insulation and all windows were replaced to enhance even more the insulation performances of the building.
The average consumptions for the three refurbished buildings is about 92,78 kWh/sm/year after an investment of the 1.619.000,00 EUR.
Reducing unintentional air leakage (that is, air sealing) through the walls, ceilings and foundations of the house is one of the most cost-effective ways to improve its energy performance and comfort in a long term perspective, although needs to be programmed in advance and initial funding have to be substantial.
In social housing it was proved that very good results can be achieved by educating tenants to energy saving and plant retrofitting (heating system, electricity etc.) and results are visible sooner.
Any retrofitting measure like ESM #3 at via Picco must be accompanied in to an education campaign in order to modify tenant’s behaviours otherwise the efficiency might not be optimal.
The optimization proposed is not a technical intervention but is aimed to improve the awareness of the tenants and to change their behaviour.
The impression gained as a result of the meeting is positive: tenants were interested in better understanding the implemented ESM and they wanted to understand how to improve the energy performance of the building and how to reduce the energy waste.
It is important to note that data collected during the monitoring period also included consumption of domestic hot water, while data collected during baseline period were related only to heating consumption. Probably for this reason energy consumption did not decrease as expected during monitoring period: it is a fact that only building Picco, 64 registered 5 percent of energy saved (leading to 2,072 MWh of savings)
We can suppose leaflets handled by ATC were partially take into consideration by tenants, or that information provided were not totally clear and understandable by whole of people. ATC should works in this field in order to fill the gap into communication between SHO and tenants. These results demonstrate that passive communication did not work. If ATC wants really to engage tenants and transfer to them good and low energy behavior, the best way to do it is, perhaps, through collective or single meeting between tenants and SHO as well as informative brochures.