Smorster

The Genius of the World's Most Efficient Heat Pump

Ziroth · 14m 40s · Watch on YouTube · 18 sources

Decision Card

Effort: Afternoon project — read Heat Geek’s free 3-step efficiency guide, then enable weather compensation and lower the flow temperature on an existing wet heating system (2–3 hours including reading the boiler/heat-pump controller manual).

Honest take: The per-layer SCOP numbers (2.5 → 3.2 → 3.7 → 4.3 → 4.8 → 5.5) are, by the video’s own admission, “illustrations based on Adam’s experience,” not measured deltas — and the headline 4.3 network average is self-reported data from Heat Geek’s own trained-installer cohort, so selection bias is baked in; the video also glosses over the Legionella management burden that low-temperature hot-water storage creates.

Concrete next steps:

  • Read and apply Heat Geek’s 3 Steps to Maximise Your Heat Pump (or Boiler) Efficiency — weather compensation and flow temperature are the highest-leverage changes (~1–2 h).
  • Browse HeatpumpMonitor.org to see real monitored installs, what SCOP they achieve, and which hardware/design choices correlate with the top of the leaderboard (~30 min).
  • If planning an install, insist on a room-by-room heat loss calculation (LiDAR-assisted tools exist, e.g. Heat Geek’s installer tooling) before accepting a quote (~1 h of vetting).
  • Skip if the property has no wet (hydronic) central heating and no heat pump plans — every layer of the pyramid assumes water-based emitters, cylinders, and pipework.

TL;DR

Ziroth interviews Heat Geek founder Adam Chapman on why their heat pump installs average ~430% seasonal efficiency (SCOP 4.3) against a UK average of ~2.8, walking an “efficiency pyramid” from SCOP 2.5 to 5.5. The gains come almost entirely from system design and operation — low-and-slow running, good pipework, weather compensation, oversized low-temperature hot water cylinders, and accurate heat-loss-based sizing — not from the heat pump unit itself.

Key Points

  • Heat pumps move heat rather than generate it, which is why efficiency above 100% (COP > 1) is physically possible — even freezing air holds extractable thermal energy. 02:33
  • Heat Geek’s network averages a SCOP of 4.3 including hot water (up to 5.0), versus a typical UK average around 2.8. 01:31
  • The big efficiency wins come from systems thinking — how the whole heating system is designed and run — not from the heat pump hardware, framed as an “efficiency pyramid” with the most important factors at the bottom. 03:26
  • A decent heat pump from a leading brand with no other considerations gets you only ~2.5 SCOP — that’s the baseline, not the result. 03:49
  • Occupant behaviour is the next layer: heating “low and slow” beats short sharp bursts, like driving 30 mph steadily instead of 90 mph with stops — taking SCOP to ~3.2. 04:12
  • Pipework and valves matter: copper pipe with a larger internal bore and gentler bend radii reduces flow resistance (plastic pipe needs fittings inserts that choke flow), and careful radiator balancing shares heat properly — SCOP ~3.7. 05:41
  • Weather compensation with modulating controls — an outdoor sensor plus a heat curve, proactive rather than reactive — is the single biggest illustrated jump, from 3.7 to ~4.3; on/off thermostat control forces inefficient overcompensation with higher flow temperatures. 09:52
  • Oversizing the hot water cylinder (e.g. 200 L where 100 L would do) lets you store water at a lower temperature, which lets the heat pump run cooler and slower — pushing SCOP to ~4.8; a large-coil cylinder helps further. 10:53
  • The most important layer is an accurate heat loss calculation (Heat Geek uses an iPad LiDAR tool that builds a virtual house model) so the heat pump and emitters can be sized for the lowest possible flow temperature — reaching SCOP 5.5, or 6.0 for space heating alone. 12:43
  • Underfloor heating’s low flow temperatures are theoretically ideal, but Adam argues the marginal SCOP gain over well-sized radiators rarely justifies ripping up floors. 13:04

Notable Quotes

“it’s not necessarily best to heat in short sharp periods low and slow is often better” — 04:10

“so heat pumps move heat rather than generate it which is why they can achieve efficiencies over 100%” — 02:33

“proactive not reactive right energy at the right place at the right time and that’s keeps that you know hold thing as steady as possible” — 10:02

Verified Claims

  1. Heat Geek’s network averages ~4.3 SCOP including hot water, far above the ~2.8 UK average. — 01:31 Sources: Heat Geek — The secret to high heat pump efficiencies (reports 4.20 heating-only average, 4.48 for Elite installers, 4.26 Elite including hot water, vs Electrification of Heat’s 2.8), Carbon Brief factcheck on UK heat pump costs Verdict: Confirmed — though the figures are Heat Geek’s own self-reported network data.

  2. The UK’s government-backed trial average SCOP is about 2.8. — 01:37 Sources: OpenEnergyMonitor community analysis of Electrification of Heat trial data, ScienceDirect — Bridging the efficiency divide: UK heat pump performance gaps (mean SPF 2.8 across 428 trial heat pumps) Verdict: Confirmed.

  3. Heat pumps move heat rather than generate it, so efficiency over 100% (COP > 1) is real, defined as heat delivered per unit of electricity. — 02:33 Sources: Wikipedia — Coefficient of performance, gridX — What is the coefficient of performance of a heat pump? Verdict: Confirmed.

  4. Steady low-output running with low flow temperature beats on/off cycling for efficiency. — 04:12 Sources: UK government report — The Effects of Cycling on Heat Pump Performance, IDM Energie — Flow temperature and heat pump efficiency Verdict: Confirmed — lower flow temperature and continuous modulated operation are well-documented efficiency drivers.

  5. Weather compensation (outdoor sensor + modulating heat curve) delivers a large efficiency jump versus on/off thermostat control. — 09:52 Sources: Energy Saving Trust — Weather compensation and other controls, Heat Geek — Heat pump commissioning and weather compensation guide Verdict: Confirmed in direction; the specific 3.7 → 4.3 jump is illustrative, but field data shows systems with weather compensation substantially outperform those without.

  6. Storing a larger hot water volume at lower temperature raises overall efficiency, with Legionella as the caveat. — 10:53 Sources: HSE — Managing legionella in hot and cold water systems (guidance: store at 60°C), Heat Geek — Legionella and hot water safety Verdict: Confirmed with caveat — lower storage temperature does improve heat pump efficiency, but UK guidance calls for 60°C storage or periodic pasteurisation cycles, a trade-off the video only mentions in passing.

  7. Adam’s own heat pump peaked at COP 8 (800%) for space heating in September 2024, with data viewable online. — 13:28 Sources: HeatpumpMonitor.org — public heat pump performance dashboard, Adam Chapman on X, topping the OpenEnergyMonitor cost leaderboard Verdict: Inconclusive — his system is publicly monitored and leads leaderboards, but the specific COP-8 September 2024 peak wasn’t independently locatable; note that a warm-shoulder-month peak COP is much easier to hit than a seasonal average.

Tools, Papers & Standards Mentioned

Follow-up Questions

  1. How much of Heat Geek’s 4.3-vs-2.8 gap survives controlling for selection bias — property type, occupant engagement, and the fact that monitored/leaderboard households are self-selected enthusiasts?
  2. What is the measured annual efficiency penalty of Legionella pasteurisation cycles on low-temperature-storage cylinders, and at what cycle frequency does the oversized-cylinder strategy stop paying off?
  3. Weather compensation is standard on most heat pump controllers — why do so many UK installs still run on/off room thermostats, and is the barrier installer training, homeowner interference, or controls interoperability (e.g. OpenTherm-style modulation support)?

Sources