Chopping simply means regularly switching systems off for short periods of time without affecting their operation. The off period makes no difference to performance but makes a big difference in saving energy and reducing costs.

The problem(s)

Householders struggle to manage their heating demand effectively. The main reasons for this are poor understanding of how the heating system works; controls that are difficult to understand and use; and a poor range of effective tools at their disposal.

The only technology currently used to manage demand in central heating systems is the thermostat. Thermostatic controls have three main problems that all result in calling for heat too early and too often:


They are locationally-biased (they measure where they are) typically in a hallway that is cooler than the rest of the house.


They are over-engineered and sensitive to a change in temperature of 0.5°C, a difference no human being can notice.


They’re designed to maintain a constant air temperature, but radiant heat is the source of most comfort.

The design of central heating systems catering for worst case weather conditions and the over-work created by the thermostat means that typically, and for most of the heating year, the system is working twice as hard as it needs to.

The solution

The Chopping Company recognises that the heating only needs to be on enough to maintain the overall heat energy in the house, not an exact air temperature. By inserting an off-period into each hour that the heating is on, Chopping saves significantly on energy use, without any difference in temperature being felt. Currently all other innovation in this market (such as the boom in smart home heating controls) is still fundamentally based around the thermostat and its attempt to maintain a precise air temperature. 

Per year, Chopping saves the average household:

500 kg

CO2e emissions

1800 kWh

of natural gas


in energy bills

Our retrofit Chopping device, the Chop-Cloc is a simple retrofit device that saves up to 30% on home heating bills. It works by inserting 15 to 45 minute off-periods to take advantage of radiant heat from the building fabric and contents. The off period makes no difference to how warm it feels inside the building, but makes a big difference in saving energy and reducing costs. Chop-Cloc is quick to fit, easy to use and pays for itself within a year.

The science

Chopping works because human comfort is predominantly delivered by radiant heat, a temperature parameter not measured or adequately accounted for in current central heating system design. Think about how you experience warmth on a sunny day; when the skies are clear and the sun is shining down on you you feel nice and warm, but if a cloud crosses in front of the sun you feel cold right away. The air temperature hasn’t changed but you can no longer feel the radiant heat from the sun.


Human comfort is predominantly delivered by radiant heat

We typically control central heating systems using thermostatic devices that are designed to maintain a steady ‘comfortable’ temperature. Heat radiating from warm solid objects in a room is a lot more influential than heat absorbed and conducted or convected by air, and yet thermostats only measure air temperature. They cannot account for all the other influences that affect our comfort. Thermostats simply aren’t designed to provide the level of control that people desire or expect, as our Special Adviser Professor explains in his latest article for us on The Tricky Notion of Comfort.

Having the heating off from anywhere between 15 and 45 minutes an hour (depending on how cold it is) really doesn’t make any difference to how warm you feel in the room. Carpets, walls, sofas, even other people get ‘charged up’ with heat energy when the heating is on and continue to radiate that heat even when the heating is switched off for a time.

The inventor speaks

With 20 years experience in the built environment and housing sectors, our inventor Garry Stewart is pretty passionate about the intricacies of heating systems. In our new video series, he highlights some important issues around heat, heating and hot air. If you’ve got any questions, want to understand more or would like to challenge Garry on anything, then please feel free to get in touch.

The Inventor Speaks: We don’t get our heat from the air

Products and services


Delivering warmth for less

Our retrofit Chopping device, the Chop-Cloc, is a unique heating control device that helps householders save up to 30% on their heating bills without noticing any difference in temperature.


Looking ahead we believe that Chopping can be applied to a whole range of applications. Our plan is to provide Chopping toolkits to suit individual needs, like new Chopping-based operating systems (or ‘Choperating systems’) for heating and cooling controls; retrofit devices like the current Chop-Cloc device for domestic heating control; Chop apps for remote control and data access; the chance to share and compare with other Choppers; and education material that are simple and easy to share.

To find out more about how Chopping can benefit your organisation and how we can work together to deliver a revolution in energy efficiency, please get in touch.