Case Study from: JMR Heating & Energy
Learn how JMR modernised a 416 m² home with heat pumps and underfloor heating, and achieved 450 %+ efficiency using h2x.
Name: Mark Denman
Role: Director
Company: JMR Heating & Energy
Location: United Kingdom
Results at a glance:
~450% heating & hot water efficiency (live NIBE Uplink data)
Stable comfort: 21.5–22.5 °C by day with a 20.5 °C night setback
Whole-home upgrade designed in h2x: cascade heat pump + UFH
See how this was done:
The Background
JMR Heating & Energy undertook a whole-home upgrade for a 416 m² residence that previously relied on an oversized 60 kW gas boiler. The objective was clear: transform an inefficient legacy system into a high performance, low-carbon solution that would deliver comfort, control, and verifiable savings.
From the outset, the team chose h2x to drive the design process. "Using h2x was pivotal, allowing for precise heat loss calculations and optimal pipe sizing and flow rates for each room," says Mark Denman. With accurate loads and balanced distribution, the design could align closely with real-world demand.
The Challenge
The original installation combined several efficiency liabilities: an ageing, high-capacity boiler, old panel radiators, single glazed windows, and a solid-wall construction. Initial assessments in h2x confirmed substantial heat losses and highlighted the need for a full system rethink rather than incremental fixes.
Beyond thermal losses, hydraulic performance was a concern. Long runs and mixed emitters can introduce pressure drops and temperature imbalances. "The strategic placement of heat pumps and careful sizing of pipework were crucial in maintaining minimal pressure drops over an 18-metre distance," notes Mark, an imperative for stable operation and comfort.
Interested to learn more about h2x?
The Solution
JMR delivered a fabric-first, systems-led design. Building-envelope upgrades included double glazing, external wall insulation, and 300 mm loft insulation to reduce demand at source. At the same time, a dual-level underfloor heating system, using 3,000+ metres of pipe, provided even, low-temperature heat delivery across the home.
To meet the calculated peak load, Mark's team selected a cascade heat pump (NIBE) configuration sized to 20.5 kW, paired with a 500 L hot water store and 750 L power tank. An optimised hydraulic design with a two-pipe buffer prevented mixing, protected system volume, and reduced compressor cycling. Weather compensation controls and h2x-driven sizing ensured every circuit operated within its ideal range.
The Results
The installation followed the h2x-designed plans and sizing throughout. Since commissioning in October, 2023, live data from NIBE Uplink shows ~450% heating and hot water efficiency, reflecting the combined impact of demand reduction, low temperature distribution, and precise hydraulic balance.
Comfort has been consistently high. Internal temperatures have remained between 21.5-22.5 °C, with a night setback to 20.5 °C, and never dropping below 20 °C. Mark sums it up: "This level of detail ensured that the heating load accurately matched each space's requirements, minimising energy waste and maximising comfort." The project has also been recognised nationally, with Heating Engineer of the Year 2024 (UK Business Awards) and East of England Engineer of the Year 2024 (Heating Installer Awards), a testament to the quality of both design and delivery.
h2x: All-In-One Tool for Calculating, Designing, Estimating, and Paperwork
Interested to learn more about h2x?
Loved by Engineers
Read More Customer Stories
Designed a 60-storey hotel in 2 hours
How Sparks+Partners sized pipework for an Australian 60‑storey building in just 2 hours, saving at least 1.5 staff days with h2x.
h2x listened, engaged and acted
How Ideal Heating accelerated design validation with hands‑on support, and embraced h2x in just 3 days through rapid innovation.
Cut design time by 50% vs. before
How MEP Design cut time by 50% on a 50-storey mixed-use tower in Manchester, UK, delivering more accurate designs with h2x.
