This Sensor Monitors. It Could Smash The Heat Loss Problem.

Heat Loss Surveys Waste Money - Twice

When an installer has to go to a property and conduct a heat loss survey. They're wasting their time. And it costs them money.

The first reason they are wasting their time is that measuring every wall, window ceiling and floor space, combined with all the added thumb sized estimations for insulation etc is just punched into software. Which delivers an answer to a maths problem based on guesswork.

This is why in the case study work we do, we witness consumers presented with multiple sized options for their heat pumps. This creates horrible indecision, decision paralysis and a loss of trust. Possibly a NO SALE.

Installers time is precious, every lost sale is £300 at least of lost time on the heat loss visit. If the heat pump is sized incorrectly, even more money is lost.

Heat loss surveys don't measure a building.

They model one. That's an important distinction. A heat loss calculation isn't watching how your house behaves.

It's predicting how it should behave based on assumptions about the building fabric, ventilation, occupancy and weather.

For most homes those assumptions are perfectly reasonable. But assumptions are still assumptions.

Do This Different

James Twallin believes we've reached the point where we don't need to rely on them. His Rebel thermal monitor approaches the problem completely differently.

Instead of asking,

"How much heat should this house lose?"

it asks,

"How much heat does this house actually lose?"

It's potentially a completely different philosophy of heating design.

The Postal Solution

Imagine a homeowner with an existing gas boiler. Instead of arranging a survey immediately, they're posted a small sensor.

It sits quietly in the property throughout part of the heating season. It records internal temperatures.

It combines those with external weather data. It watches how quickly the house warms up. How slowly it cools down.

How much heat is needed to maintain comfort.

Most importantly, it observes the building itself rather than making assumptions about it. By the end of the monitoring period, the installer isn't working from estimates. They're working from evidence.

He Did A Case Study - A Difficult One

That's exactly what happened during the heating design for a 200-year-old church.

Rather than relying solely on theoretical heat-loss calculations, sensors were installed while a known heat source warmed the building. The resulting temperature data allowed the team to characterise how that specific church stored and released heat, giving them confidence that the chosen air-to-air heat pump system would meet the required comfort levels.

As James explains:

"My sensor basically allows you to measure the space rather than model the space."

That single sentence may be the most disruptive idea in domestic heating today.

What's The Impact?

The implications go much further than sizing heat pumps.

If the cost of manufacturing these monitors falls low enough, why wouldn't every installer simply post one to prospective customers?

No first visit. No tape measure. No assumptions about thermal mass. No arguments over whether cavity insulation exists.

Just data.

Months of it.

Collected from the building itself.

The Marketing + Sales Eureka Moment

It could change sales. Imagine telling a homeowner:

"We've already monitored your property. We know exactly how your current boiler behaves. We know how much heat your home actually needs. Here's the evidence."

That's a very different conversation from,

"We've modelled your house."

What Will MCS Do?

Today's industry can't simply abandon conventional heat-loss calculations. Current standards, including MCS requirements, still rely on established calculation methodologies for system design and compliance.

BUT, History suggests that engineering eventually favours measurement over estimation whenever practical measurement becomes affordable.

Cars gained lambda sensors instead of fixed fuelling tables.

Modern engines gained knock sensors instead of conservative ignition maps.

Aircraft gained real-time instrumentation instead of relying solely on handbook performance.

Measurement replaces assumption because reality is always richer than a model.

The Real Story?

James Twallin hasn't built a smarter heat-loss calculator.

He's built something that asks whether, we need to calculate heat loss in quite the same way at all.

And if measuring reality becomes cheaper than modelling it, every installer, every homeowner and every heat pump manufacturer will eventually have to answer the same uncomfortable question.

Why are we still guessing when we could simply measure?

If you want to join the waitlist for this monitor: https://www.rebelheat.co.uk/