Danish, Estonian and Finnish NZEB requirements comparison with European Commission recommendations for office buildings in Nordic and Oceanic climates

Direct comparison of building energy performance levels between countries is usually not possible due to differences in climatic conditions, calculation methods, primary energy (PE) factors and input data. The aim of this paper is to analyse the differences in nearly zero energy office buildings requirements and energy calculation methodology in Denmark, Finland, and Estonia. The study is based on a newly built Estonian office building, designed to meet national NZEB requirements. To account for the climatic differences between the countries a heating-degree-days-based correction factor was applied for building envelope thermal transmittance. NZEB requirements for each country are compared with European Commission (EC) recommended values (EU 2016/1318) using normalization and benchmarking through detailed computer simulations. National NZEB primary energy threshold was needed to be reduced by 7% in Denmark and by 23% in Estonia to meet EC recommendations. At the same time, the flagship reference building, that was better than Estonian NZEB, met both Nordic and Oceanic EC recommendations. Finnish NZEB requirement was not exceeded with any building configuration applied in this study, indicating that Finnish NZEB is considerably less strict compared to Danish and Estonian ones

Compliance with Summer Thermal Comfort Requirements in Apartment Buildings

In this study we have investigated the compliance with summer thermal comfort requirements of 16 new apartment buildings in Estonia by modelling and simulating dwellings using energy and indoor climate simulation software IDA-ICE. We also conducted field measurements of indoor temperature in 17 dwellings in 16 different apartment buildings during the period from 1 July to 31 August 2014. It has been found that 81.3% of the simulated buildings do not comply with the requirements. Measurements show that overheating can be a problem in apartment buildings also in cold climate regions

Ilmanvaihto- ja jäähdytysjärjestelmien resilienssi lämpöaaltojen ja hengitystieinfektioiden suhteen : Uudis- ja korjausrakennusten teknisten ratkaisujen toiminta muuttuvissa olosuhteissa

Tutkimuksessa tehtiin laskennallisia tarkasteluja helleaaltojen vaikutuksista sisälämpötilaan sekä kenttämittauksia ja virtaussimulointeja ilmanvaihdon mitoituksen merkityksestä hengitystieinfektioiden torjunnassa. Lisäksi arvioitiin korkeiden lämpötilojen terveyshaittoja sekä influenssaviruksen terveysvaikutuksien ja koronapandemian merkitystä Suomen ylikuolleisuuteen. Passiivisilla auringonsuojaratkaisuilla ja ilmanvaihdon tehostuksella voidaan vähentää rakennusten ylilämpenemistä, mutta ne eivät yksistään riitä torjumaan sitä. Helleaalloista aiheutuu Suomessa vuosittain keskimäärin noin 110 ennenaikaista kuolemaa ja 170 sairaalahoitojaksoa, ja tulevaisuudessa haitat voivat moninkertaistua. Asuntojen ylilämpenemisen torjuntatoimien avulla on mahdollista ehkäistä merkittävä osuus vakavista terveyshaitoista. Nykyiset ilmavirrat ovat opetustiloissa ja kuntosalissa riittäviä hengitysinfektioriskin hallintaan. Avotoimistossa noin 20 %:a pienempi henkilömäärä voidaan nähdä järkevänä ratkaisuna epidemiatilanteessa. Hengitystieinfektiot ovat yleisin lyhyiden työstä poissaolojen syy Suomessa ja ne aiheuttavat sekä työnantajille että yhteiskunnalle kustannuksia sairauspoissaoloina, lisääntyneinä terveydenhuollon menoina ja suurentuneena kuolleisuutena.Tämä julkaisu on toteutettu osana valtioneuvoston selvitys- ja tutkimussuunnitelman toimeenpanoa. (tietokayttoon.fi) Julkaisun sisällöstä vastaavat tiedon tuottajat, eikä tekstisisältö välttämättä edusta valtioneuvoston näkemystä

Overheating Prevention and Daylighting in Buildings without Mechanical Cooling. clekuumenemise v\ue4ltimine ja loomuliku valguse tagamine mehaanilise jahutuseta hoonetes

Doctoral thesis 54/2019 Doktorit\uf6\uf6 54/201

Heating Sizing Power Reduction in Buildings Connected to District Heating with Dynamically Controlled DHW Setback and Flow Limiters

| openaire: EC/H2020/856602/EU//FINEST TWINSSpace Heating (SH) substations in District Heating-based (DH) systems are typically dimensioned at the design outdoor temperature without accounting for internal and solar heat gains. In residential buildings, the total required DH power typically also includes the need for Domestic Hot Water (DHW). This practice results in oversized substations and high DH design flow rates, which, due to heat gains and building thermal mass utilization in building operation, rarely, if ever, occur. Modern buildings maintain the desired indoor temperature with lower heating power by controlling the SH supply temperature with an outdoor-air-dependent heating curve and heating water flow with room unit thermostats. Applying a dynamic heating control algorithm can be considered one option to reduce the required DH power and optimize the DH network. Another possibility to decrease the needed power is controlling the DH flow by prioritizing DHW production and limiting the DH flow for SH. This study proposed a novel sizing method for the DH substation that quantifies the effects of dynamic control and flow limiters. Building models with detailed hydronic plants, accounting for internal heat gains, and using conventional and dynamic heating controls were developed in the IDA Indoor Climate and Energy simulation tool. The results show a potential DH side power reduction of up to 25%.Peer reviewe

Measured and simulated energy performance of OLK NZEB with heat pump and energy piles in Hämeenlinna

In this work, measured energy use of the building space heating, ventilation supply air heating, appliances and lighting is compared against simulated energy use modelled in IDA ICE. As built energy need and detailed measured input data is applied in building model calibration procedure. Calibrated building model energy performance is studied in both measured and test reference year climate conditions. Previously modelled as built plant automation and implemented control logics are compared against measured. Geothermal plant in this study consists of heat pump, solar collectors, boreholes and energy piles. Heat pump SCOP estimated by post processing according to heat pump manufacturer's performance map is compared against measured SCOP on the monthly basis. Opinion on actual plant operation is given and energy performance improvement potential is quantified. Important parameters for successful building model calibration are presented. Building compliance with Finland NZEB requirements are assessed. The results show good match with measured energy use after the model calibration.Peer reviewe

A comparative study on cooling period thermal comfort assessment in modern open office landscape in Estonia

| openaire: EC/H2020/856602/EU//FINEST TWINSLocal thermal comfort and draught rate has been studied widely. There has been more meaningful research performed in controlled boundary condition situations than in actual work environments involving occupants. Thermal comfort conditions in office buildings in Estonia have been barely investigated in the past. In this paper, the results of thermal comfort and draught rate assessment in five office buildings in Tallinn are presented and discussed. Studied office landscapes vary in heating, ventilation and cooling system parameters, room units, and elements. All sample buildings were less than six years old, equipped with dedicated outdoor air ventilation system and room conditioning units. The on-site measurements consisted of thermal comfort and draught rate assessment with indoor climate questionnaire. The purpose of the survey is to assess the correspondence between heating, ventilation and cooling system design, and the actual situation. Results show, whether and in what extent the standard-based criteriafor thermal comfort is suitable for actual usage of the occupants. Preferring one room conditioning unit type or system may not guarantee better thermal environment without draught. Although some heating, ventilation and cooling systems observed in this study should create the prerequisites for ensuring more comfort, results show that this is not the case for all buildings in this study.Peer reviewe

Redefining cost-optimal nZEB levels for new residential buildings

In the member states of the European Union (EU), nearly-Zero Energy Buildings (nZEB) are becoming mandatory building practice in 2021. It is stated, that nZEB should be cost-optimal and the energy performance levels should be re-defined after every five years. We conducted cost-optimality analyses for two detached houses, one terraced house and one apartment building in Estonia. The analysis consisted on actual construction cost data collection based on bids of variable solutions for building envelope, air tightness, windows, heat supply systems and local renewable energy production options. For energy performance analysis we used dynamic simulation software IDA-ICE. To assess cost-effectiveness, we used Net Present Value (NPV) calculations with the assessment period of 30 years. The results for cost-optimal energy performance level for detached house with heated space of ~100 m2 was 79 kWh/(m2 a), for the larger house (~200 m2) 87 kWh/(m2 a), for terraced house with heated space of ~600 m2 71 kWh/(m2 a) and for the apartment building 103 kWh/(m2 a) of primary energy including all energy use with domestic appliances. Thus, the decrease in cost-optimal level in a five-year period was ~60% for the detached house and ~40% for the apartment building, corresponding to a shift in two EPC classes.Peer reviewe