Identifying typical hourly DHW energy use profiles in a hotel in Norway by using statistical methods

Dmytro Ivanko,Harald Taxt Walnum,Igor Sartori,Natasa Nord,Thale Sofie Wester Plesser,Åse Lekang Sørensen,S.I Tanabe,P Wargocki,G Cao,I Nastase,L Mazzarela,C Inard,H Zhang,J Kurnitski,M.C Gameiro Da Silva

doi:10.1051/e3sconf/201911104015

Abstract

The aim of this research is to improve the existing approaches of domestic hot water (DHW) energy use analysis in buildings. A comprehensive statistical analysis of hourly DHW energy use for a hotel in Oslo, Norway, was performed. To recognize the trend of DHW energy use over several years, Centered Moving Average method was applied. To increase the accuracy of DHW energy use analysis, it was proposed to identify the months and days of the week with similar characteristics of DHW energy use and build unified profiles for them. For this purpose, the approaches based on the student’s t-tests and Fisher’s test was proposed. The analysis allowed us to detect two seasons of DHW energy use. In addition, it was revealed that behavior of DHW energy use on Mondays significantly different from other working days. To recognize the timing of peak and average and low DHW energy use, method of statistical grouping of the hourly energy use was utilized. The typical profiles of DHW energy in the hotel were obtained. The profiles proposed in the present article more reliably reflect the regimes of DHW energy use in the hotel and take into account factors that have influence on DHW use.

Highlights

According to the European Commission, buildings are responsible for approximately 40% of energy use and 36% of CO2 emissions in the EU [1]
The number of seasons of domestic hot water (DHW) energy use in the year and the months included in each season can be identified
An important step in achieving energy efficiency in buildings is reducing the needs in DHW tap energy use

Summary

Introduction

According to the European Commission, buildings are responsible for approximately 40% of energy use and 36% of CO2 emissions in the EU [1]. In order to achieve this goal, heating, cooling, and ventilation systems in buildings should be designed and operated to attain low energy use [4]. In countries with cold climate, energy used to heat domestic hot water (DHW) is much smaller than the energy use required for heating the building. For this reason, during the last decades, DHW energy use has had little focus in Norway and other countries [5]. The energy use for heating is significantly reduced [6]. For future prospects in achieving energy efficiency in buildings − reducing DHW energy use is an important task. Global warming potential (GWP) and primary energy demand (PED) for a range of DHW systems has high carbon footprint [6]

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Conclusion