Energy transition

This paper investigates how a simulated room’s energy and temperature performance are affected if its underfloor heating control is modelled with increasing detail. Experiments were performed to develop and calibrate an empirical model of wax motor and to calibrate the valve curve. These models were used to implement and test the On/Off and proportional-integral (PI) control processes at various levels of modelling detail. Controllers were implemented by gradually adding optimized control parameters, signal delay, calibrated valve curve, signal modulation, and actuator modelling. The On/Off control dead band and PI parameters exhibited the largest impact, reducing energy use (1%–5%) and temperature fluctuations (ca 1 K). Modulating the PI output signal increased temperature fluctuations to the same amplitude as On/Off with 0.5 K dead band, increasing space heating demand by 1.3%. The wax actuator counted for less than 1%; however, it increased time delays to maximally 7 min and remarkably changed the mass flows.

Parts , T M , Ferrantelli , A , Naar , H , Thalfeldt , M & Kurnitski , J 2023 , ‘ Wax actuator’s empirical model development and application to underfloor heating control with varying complexity of controller modelling detail ‘ , JOURNAL OF BUILDING PERFORMANCE SIMULATION . https://doi.org/10.1080/19401493.2023.2201818

Our newly published paper demonstrates how choosing different #energytransition policies at the European level can radically affect renovation rates, costs, CO2 #emissionsreduction, and #energyefficiency. MDPI TalTech – Tallinn University of Technology Aalto University

https://www.mdpi.com/1882366

Abstract

Energy renovations of the building stock are a paramount objective of the European Union (EU) to combat climate change. A tool for renovation progress monitoring is energy performance certificate (EPC) labelling. The present study tested the effect of different EPC label classifications on a national database, which comprises ~25,000 EPC values from apartment buildings, detached houses, office buildings, and educational, commercial, and service buildings. Analysing the EPC classes labelling resulting from four different EU methods, we estimated the annual renovation rates, costs, energy savings, and CO₂ emissions reduction that would affect the national building stock if each of them was adopted, to fulfil the European Climate Target Plan by the year 2033. The ISO 52003-1:2017 two-point and one-point methods determined a very uneven distribution of renovation rates, from 0.45% to ~9%. Conversely, the Directive 15% recently proposed in COM/2021/802 with uniform rates determined smaller differences and standard deviation, not pushing renovations above 3.70%, namely a rate that once fine-tuned can stimulate realistic, yet effective renovation campaigns. The major differences in renovation rates provided by the studied methods show the need for a harmonized strategy such as the Directive proposal to enable achievement of European targets.

Keywords: Energy Performance Building Directive (EPBD); Energy Performance Certificates (EPC); carbon emissions; energy efficiency; statistical analysis; European Green Deal

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