What goes wrong, and why
Short, specific pieces on heat pump design, retrofit and measured performance. Written by the engineers doing the work, mostly about the problems we keep meeting.
Most of these come out of feasibility work, heat pump design and what monitoring shows once a system is running.
Making the case now the funding has gone
PSDS was cancelled in June 2025 and the Low Carbon Skills Fund has had no allocation since 2024/25. What is still open, why the old business case stops working, and the three arguments that do still get approved.
Why commercial heat pumps underperform after installation
Elevated flow temperatures, inadequate distribution, frequent cycling, control faults and incomplete setup. The usual causes of the gap between designed and delivered performance.
What estates teams should check before replacing gas boilers with heat pumps
Heat consumption patterns, flow temperatures, electrical capacity, hot water demand, controls and data availability. The checks worth completing before anyone specifies plant.
Why hybrid heat pump systems can be a cost-effective route to decarbonisation
Heat pumps covering most of annual demand while boilers are retained for peak load, resilience and high-temperature duty — cutting carbon without the cost of full electrification.
Why domestic hot water is often the hardest part of heat pump design
Temperature requirements, storage and recovery, undersized heat exchangers and poor control strategy. Where heat pump efficiency is most often lost.
What we keep coming back to
The performance gap
Designed efficiency and delivered efficiency are different numbers, and on heat pump retrofit the difference is often large. Almost everything we write comes back to this.
Running cost
Electricity at 4.3 times the price of gas changes every business case. Pretending otherwise is how schemes lose the confidence of the people who signed them off.
Controls
The cheapest carbon in most buildings and the most consistently neglected. Weather compensation, sequencing and setbacks left at commissioning defaults.
Send us the scope
A building, a stage, a date. We will come back with whether we can take it, what it costs and what we would need from you — usually within a working day.
Ask us directly
Can we ask a technical question without commissioning work?
Yes. A short, specific question about a scheme, a flow temperature or an electrical constraint usually gets a straight answer by email. If it turns into a piece of work we will say so.
Do you write or speak for publications and events?
Occasionally, on heat pump retrofit and measured performance. Get in touch if you are looking for a contributor or speaker on those topics.