Earth Notes: PhD Research Plan Sketch (2024)

Updated 2024-04-05.
An outline plan for research into optimising UK domestic wet heating system retrofit. #PhD #heating #research



A sketch research plan in early 2024, with the aim of supporting my confirmation viva and the next seven years' work on making UK (wet) home heat retrofit work as well as possible.

My colleague Uche a structure:

Current Topics of Interest

This includes possible 'further work' arising from research already done.

  1. Extend domestic TRV / heat-pump / temperature-regulation interaction investigation [hart-davis2023waste] to high-fidelity models and/or physical housing stock.
  2. Investigate and catalogue domestic heat-pump temperature regulation schemes in use and as recommended/regulated across northern Europe, possibly with a view to optimising regulation/advice for installers and occupiers.
  3. Thermochromic radiator stickers to help tune condensing boilers and de-risk a move to a heat-pump.
  4. Heat-pump retrofits — must fabric improvements happen first or at all (eg [govUK2024historic]), and if not, how should outcomes be optimised (eg [eyre2023fabric])?
  5. Improving agency and understanding for users of heat pumps to end up with cheaper more comfortable homes — controls that work and a mandated uniform common subset? This may involve novel UI/UX including psychoacoustically-driven audio salience encoding [johnston1988transform]. Almost certainly requires collaboration across fields.
  6. Maximising co-benefit health improvements eg [donkin2024health].
  7. Developing visualisation and sonification schemes to improve heat-pump user understanding and agency.
  8. Describe and explore current heat battery cross-vector control algorithm and future w/hp version.

There are other energy and efficiency topics of interest beyond home heating ultimately driven by reducing emission reductions, such as tuning and optimisation of RSS podcast and other feeds.

Plan Sketch


The central topic to be researched is how to decarbonise UK (wet) home heating well.

UK residential heating, responsible for 10 to 20% of the UK's carbon footprint [CCC2019technical], must decarbonise as part of Net Zero goals to tackle climate change. Gas-fired radiator systems in circa 20 million UK dwellings standing now that will still be in use in 2050 are likely to be replaced with heat pump systems [UKNIC2023assessment] [ESC2022EoH] [EHS2022energy] [govUK2022boiler] [reguis2021challenges] [piddington2020housing] [CCC2019technical] [hart-davis2023retrofits]. Some current heating systems, especially in dense urban areas, will be replaced with district heating [henretty2020efficiency] [sorensen2023excess] [makasis2023pavements]. Some low demand properties may have simple electric resistive heating with or without storage [govUK2021CODE].

Retrofit done well is not simply a technical exercise: swapping out one ignored white metal box for another. The swap from gas to heat pump also requires resolving challenges in finance, space for water storage and external units, disruption for possible radiator and pipework replacement, disruption and costs of removal of the gas supply in due course, getting used to old noises and quirks going and new ones in their place, learning to provide demand flexibility such as grid responsiveness, understanding new controls and ways of working with the heating. Retrofit on the required scale is a human, social [ambrose2023JUSTHEAT] and political undertaking too.

This research programme aims to find out where parts of the decarbonisation journey can be improved, from regulation through tradesperson upskilling [cretu2022scale] [CSE2023retrofit] [LCP2023installer] [toleikyte2023deployment] to improved user agency and comfort and health [donkin2024health], and then help make the necessary impact.

Literature review

Domestic heat-pump / zoning / thermal regulation

Current Europe-wide thermal regulation schemes for domestic heat-pumps

Thermochromic radiator stickers

Heat-pump retrofits - must fabric improvements happen first or at all?

Improving agency and understanding for users of heat pumps

Maximising co-benefit health improvements with heat-pump retrofits

Visualisation and sonification to improve heat-pump user agency

Describe and explore heat battery cross-vector control algorithms

Research design/plan

Research objectives

Find for robust reasonable maximum carbon emission savings at a reasonable price. Not necessarily a 'perfect' engineering solution.

Objectives include "impact" and "extension": disseminating findings to and beyond academia, eg to practitioners and end-users to gain real-world reduction in climate change and its effects (mitigation and adaptation).


Data gathering

Data analysis




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