An analysis methodology for large-scale deep energy retrofits of existing building stocks: Case study of the Italian office building

Luddeni, Giacomo; Krarti, Moncef; Pernigotto, Giovanni; Gasparella, Andrea

doi:10.1016/j.scs.2018.05.038

Cited by 90 publications

(60 citation statements)

References 25 publications

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“…Nonetheless, the introduction of the new regulation on the performance of buildings [3], i.e., the introduction of nearly zero energy buildings (NZEBs) as the new building target [4,5], will force the building sector to handle simultaneously the heat losses and the air quality issues, since ventilation approaches not properly designed will likely not fulfill the limitation on energy need for space heating typical of the NZEBs [6][7][8]. Apart from new constructions, the strategic challenge in view of the reduction of the energy consumption of the building sector is the energy retrofit of the existing buildings [9][10][11][12][13]. This is even more important in countries (like Italy) characterized by a huge percentage (roughly 70%) of buildings built before any regulatory indication on building energy efficiency [14][15][16] and then without any carefulness to the ventilation issues.…”

Section: Introductionmentioning

confidence: 99%

The Effect of Ventilation Strategies on Indoor Air Quality and Energy Consumptions in Classrooms

et al. 2019

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Most of the school buildings in Italy are high energy-demanding buildings with no ad-hoc ventilation systems (i.e., naturally-ventilated buildings). Therefore, reducing the heat losses of schools represent the main aspect to be dealt with. Nonetheless, the indoor air quality of the building should be simultaneously considered. Indeed, to date, energy consumptions and air quality are considered as incompatible aspects especially in naturally-ventilated buildings. The aim of the present paper is to evaluate the effect of different ventilation and airing strategies on both indoor air quality and energy consumptions in high energy-demanding naturally-ventilated classrooms. To this purpose, an Italian test-classroom, characterized in terms of air permeability and thermophysical parameters of the envelope, was investigated by means of experimental analyses and simulations through CO2 mass balance equation during the heating season. The air quality was assessed in terms of indoor CO2 concentrations whereas the energy consumptions were evaluated through the asset rating approach. Results clearly report that not adequate indoor CO2 concentrations are measured in the classroom for free-running ventilation scenarios even in low densely populated conditions (2.2 m2 person−1), whereas scheduled airing procedures can reduce the indoor CO2 levels at the cost of higher energy need for ventilation. In particular, when airing periods leading to the air exchange rate required by standards are adopted, the CO2 concentration can decrease to values lower than 1000 ppm, but the ventilation losses increase up to 36% of the overall energy need for space heating of the classroom. On the contrary, when the same air exchange rate is applied through mechanical ventilation systems equipped with heat recovery units, the ventilation energy loss contribution decreases to 5% and the overall energy saving results higher than 30%. Such energy-saving was found even higher for occupancy scenarios characterized by more densely populated conditions of the classroom typically occurring in Italian classrooms.

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Section: Introductionmentioning

confidence: 99%

The Effect of Ventilation Strategies on Indoor Air Quality and Energy Consumptions in Classrooms

et al. 2019

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“…From the review of the studies linked to detailed procedures, we may highlight that detailed results can be achieved with a short simulation time step. Many studies such as [17][18][19][20][21][22][23][24][25][26][27][28][29] present detailed sensitivity analyses in the variations of their parameters, and even hourly analyses of the results. Also, the high computational cost derived from the use of tools such as EnergyPlus [30] or TRNSYS [31] and the simulation of thousands of cases should be mentioned.…”

Section: Procedures and Methodologiesmentioning

confidence: 99%

Design of the Refurbishment of Historic Buildings with a Cost-Optimal Methodology: A Case Study

et al. 2019

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The transformation of existing buildings into Near Zero Energy Buildings or even positive energy buildings remains a major challenge. In particular, historic buildings are an important cultural heritage that, in most cases, may be rehabilitated and reused for new purposes. However, achieving higher efficiencies in those buildings presents many difficulties, since there is a need to preserve aesthetic values and minimize impact on the buildings’ initial construction. In this work, a roadmap that allows rehabilitating a building from the eighteenth century is developed, turning it into a landmark building, to be used as a museum in the near future. The procedure is based on 3D models using REVIT software and detailed energy simulations supported by a cost-optimal methodology. The results reveal how conventional methodologies shown in the literature may improve the energy performance of the buildings during the heating regime, but performance may deteriorate during the cooling season. For that reason, the present study includes the design of a night ventilation system which allows not only solving this problem but also to reducing the cooling demands by more than 43% with little additional costs. In conclusion, historic buildings (which traditionally have a high thermal mass) have increased thermal storage potential by using the structures of the buildings themselves as well as passive cooling techniques.

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“…• Detailed results can be obtained in short simulation time intervals. Many studies, such as [41][42][43][44][45][46][47][48][49][50][51][52][53], present sensitivity analyses with detailed variations of their parameters and even hourly analyses of the results.…”

Section: Methodologies To Design Energy Savings Plans In Existing Buimentioning

confidence: 99%

Systematic Simplified Simulation Methodology for Deep Energy Retrofitting Towards Nze Targets Using Life Cycle Energy Assessment

et al. 2019

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The reduction of energy consumption in the residential sector presents substantial potential through the implementation of energy efficiency improvement measures. Current trends involve the use of simulation tools which obtain the buildings’ energy performance to support the development of possible solutions to help reduce energy consumption. However, simulation tools demand considerable amounts of data regarding the buildings’ geometry, construction, and frequency of use. Additionally, the measured values tend to be different from the estimated values obtained with the use of energy simulation programs, an issue known as the ‘performance gap’. The proposed methodology provides a solution for both of the aforementioned problems, since the amount of data needed is considerably reduced and the results are calibrated using measured values. This new approach allows to find an optimal retrofitting project by life cycle energy assessment, in terms of cost and energy savings, for individual buildings as well as several blocks of buildings. Furthermore, the potential for implementation of the methodology is proven by obtaining a comprehensive energy rehabilitation plan for a residential building. The developed methodology provides highly accurate estimates of energy savings, directly linked to the buildings’ real energy needs, reducing the difference between the consumption measured and the predictions.

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An analysis methodology for large-scale deep energy retrofits of existing building stocks: Case study of the Italian office building

Cited by 90 publications

References 25 publications

The Effect of Ventilation Strategies on Indoor Air Quality and Energy Consumptions in Classrooms

The Effect of Ventilation Strategies on Indoor Air Quality and Energy Consumptions in Classrooms

Design of the Refurbishment of Historic Buildings with a Cost-Optimal Methodology: A Case Study

Systematic Simplified Simulation Methodology for Deep Energy Retrofitting Towards Nze Targets Using Life Cycle Energy Assessment

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