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Estimation of building heat transfer coefficients from in-use data: Impacts of unmonitored energy flows

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journal contribution
posted on 21.06.2019, 13:18 by Matthew Li, David AllinsonDavid Allinson, Kevin LomasKevin Lomas

Purpose

The purpose of this paper is to identify the impact of traditionally unmonitored energy sources and sinks on assessment of the as-built thermal performance of occupied homes. The analysis aims to demonstrate the potential scale of uncertainties introduced in a heat balance estimation of the heat transfer coefficient (HTC) when using in-use monitored data.

Design/methodology/approach

Energy flows for two UK homes – one a 1930s dwelling with high heat loss, the second a higher-performing 2014-built home – are predicted using the UK Government’s standard assessment procedure (SAP) and visualised using Sankey diagrams. Selected modelled energy flows are used as inputs in a quasi-steady state heat balance to calculate in-use HTCs as if from measured data sets gathered in occupied homes. The estimated in-use HTCs are compared against SAP-calculated values to illustrate the impact of including or omitting various heat sources and sinks.

Findings

The results demonstrate that for dwellings with low heat loss, the increased proportion of heating demand met by unmetered internal and solar gains informs a greater sensitivity of a heat balance estimation of the HTC to their omission. While simple quasi-steady state heat balance methods may be appropriate for dwellings with very high heat loss, alternative approaches are likely to be required for those with lower heat loss.

Originality/value

A need to understand the impacts of unmetered heat flows on the accuracy with which a building’s thermal performance may be inferred from in-use monitored data is identified: this paper illustrates the scale of these impacts for two homes at opposite ends of the energy performance scale.


Funding

Engineering and Physical Sciences Research Council (EPSRC) [grant number EP/L01517X/1].

History

School

  • Architecture, Building and Civil Engineering

Published in

International Journal of Building Pathology and Adaptation

Volume

38

Issue

1

Pages

38 - 50

Citation

LI, M., ALLINSON, D. and LOMAS, K.J., 2019. Estimation of building heat transfer coefficients from in-use data: impacts of unmonitored energy flows. International Journal of Building Pathology and Adaptation, 38 (1), pp.38-50.

Publisher

Emerald Publishing Limited

Version

VoR (Version of Record)

Rights holder

© 2019, Matthew Li, David Allinson and Kevin Lomas

Publisher statement

This article is published under the Creative Commons Attribution (CC BY 4.0) licence. Anyone may reproduce, distribute, translate and create derivative works of this article (for both commercial & non-commercial purposes), subject to full attribution to the original publication and authors. The full terms of this licence may be seen at http://creativecommons.org/licences/by/4.0/legalcode

Acceptance date

11/05/2019

Publication date

2019-07-03

ISSN

2398-4708

Language

en