Assessment of the energy renovation potential for urban neighbourhoods

U radu je provedena analiza potencijala energetske obnove naselja Trnsko u Novom Zagrebu. Naselje je modelirano u računalnom programu Rhinoceros 3D, a primjenom računalnog programa UMI (eng. Urban Modeling Interface) simulirana je potrebna i isporučena energija za postojeće stanje zgrada te nakon primjene mjera energetske obnove. Budući da je UMI namijenjen za modeliranje većih cjelina, glavni cilj energijskih analiza je brzo provođenje simulacija uz prihvatljivu točnost rezultata. Kako bi se utvrdilo koliko uvedena pojednostavljenja utječu na rezultate, napravljena je usporedba rezultata potrebne i isporučene energije za objekt Osnove škole Trnsko korištenjem računalnih programa UMI te TRNSYS. S ciljem određivanja optimalne debljine toplinske izolacije i perioda povrata investicije, provedena je ekonomska analiza za stambene zgrade za različite debljine izolacije vanjskog zida. S obzirom da UMI omogućuje 3D modeliranje cijelog grada, dobiveno odstupanje u točnosti rezultata unutar 20% za potrebnu energiju za grijanje i hlađenje u usporedbi s TRNSYS-om smatra se prihvatljivim. Nakon izmjene toplinskih svojstava ovojnice, koje uključuje dodatak izolacije vanjskog zida i krova te zamjenu jednoslojnih prozora s dvoslojnim moguće je ostvariti smanjenje potrebne, odnosno isporučene energije za grijanje u iznosu od 74%, a smanjenje rashladne energije za 7%. Provedbom ekonomske analize za različite debljine izolacije vanjskog zida, određena je optimalna debljina izolacije 14 cm, a period povrata investicije iznosi 31,7 godina.In this study an assessment of the energy renovation potential was analyzed for Trnsko, a neighbourhood in the city of Zagreb. The settlement model was designed by Rhinoceros 3D computer program, after which the energy simulation was done using The Urban Modeling Interface (UMI) that provides various energy analyses. UMI was used to calculate the amount of required and delivered energy for the existing building condition as well as after the implementation of energy renovation measures. Since UMI is intended for large unit modeling, the main goal of energy analyses is a fast simulation performance with acceptable result accuracy. In order to evaluate the reliability of UMI, additional energy simulation was done in TRNSYS software for Elementary School Trnsko. With the aim of determining the optimal thermal insulation thickness and the investment return period, an economic analysis was conducted for residential buildings in Trnsko, taking into account different thicknesses of external wall insulation. The obtained deviation in the accuracy of the results is 20% for the required energy for heating and cooling compared to TRNSYS. This is considered acceptable in relation to the advantages of urban modeling possibilities. After changing the thermal properties of the layer, which included the insulation of external walls and roofs as well as a window replacement, the delivered energy for heating decreased by 74%, while the delivered energy for cooling decreased by 7%. By conducting an economic analysis for different thicknesses of the insulation of the outer wall, results show that the optimal thickness of the insulation is 14 cm for which the investment return period is 31,7 years