Midwinter: what’s ‘chopping’ got to do with it?

The Chop Cloc: a new way of thinking of domestic warmth

Zaria_Sequoia3As the spring warms, we gratefully lower our heating and allow the sun to stream through the open doors. I find that my skin almost doesn’t remember the touch of warm sun, and of course our little daughter, born in the middle of frozen winter, is experiencing the first proper sun of her little life. She’s even got a slight suntan (very bad parenting..tut tut).

Just before her birth a visitor loomed out of the winter mist on Blythe Hill: Garry Stewart from Scotland bearing a Chop Cloc. This is a new and ingenious invention designed to facilitate the practice of ‘chopping’ which means cutting out your boiler for short periods, allowing the heating to ‘coast’ in your home, without dropping the temperature noticeably. It’s a way of saving significantly on heating costs and carbon emissions while maintaining a healthy temperature. It’s called a ‘clock’ because it kind of looks like a clock, and it works based on time, see the images here:


You can set it to cut out (‘chop’) from 15 to 45 minutes in the hour, by simply twiddling the dial. It has a ‘no chop’ setting too, if you just want things full on. Apparently, if you find your comfort zone you shouldn’t need to change it that often.

It has to be wired into your boiler, see the image here of Garry doing the doings.















Garry_wiringupThere are several useful things about the Chop Cloc. Firstly, and most relevantly to us, it is a ‘retrofit’ device, designed to be wired into existing boiler systems to make them more efficient. It’s claimed to save up to 30% on heating bills, and is designed to address both carbon emissions and fuel poverty. Apparently fuel poverty is much more widespread than you’d think, with average yearly fuel bills reaching nearly £600 this year, a shocking rise of 63% from 2008. This, combined with the economic fallout from the banking crisis and subsequent recession, means that more of us are challenged by fuel bills than previously.

Heating of course became priority for us when having a new baby in the depths of winter, so Garry’s visit was most welcome (in retrospect I think of him as one of the three wise kings come a bit early and bearing a very useful gift). In our house we had discussed keeping the heating on at night, which for us environmentalists felt like buying a four-wheeled drive and making friends with Jeremy Clarkson all of a sudden (ok, we probably take ourselves too seriously). The ‘Chop Cloc’, however, changed this and made us feel better as well as saving us quite a bit of cash. My devoted partner turned it to ‘15’ each evening, which means that the boiler cut out for 15 minutes in each hour, thus saving us money and energy and making night feeds sooooo much more comfortable. Anyone who’s had a new baby knows how those early months are: bleary-eyed, feeding at lonely freezing hours of the night, and feeling as though you are the only one in the world awake.

The concept of the Chop Cloc relies on the fact that actually most heating systems overwork, and while they are efficient at maximum power at the coldest times of the year, they waste energy most of the time in our temperate climate. Even if the boiler itself is efficient at converting gas to heat, using that heat well, to keep us comfortable, is about delivering it sufficiently without oversupplying it when it’s not really needed. Garry explained that he is suspicious of thermostats, mainly because they don’t really reflect human comfort: apparently we don’t notice slow changes in temperature up to 2°C, it’s only more extreme changes that bother us. As long as we stay within our ‘comfort zone’ we are fine.

Thermostats are usually installed in passages or landings, which are areas of the home where people don’t spend a lot of time, so they are generally a bit colder, thus making our boilers hike it up unnecessarily. Crucially, however, thermostats mainly measure air temperature, which is only a partial measure of the whole temperature and comfort of the house. Radiant heat from walls, floors, ceilings, and furniture plays a big part in maintaining a comfortable temperature inside a building, while apparently the thermostat is a blunt instrument for regulating this. Plus, no-one understands them (I admit, I don’t understand mine, do you?). The chop clock means that you can save a reasonable amount of energy and money by simply cutting out your boiler and avoiding the overproduction that I’ve detailed above. And it’s easier to understand than a thermostat.

The Chop Cloc is seen as a great invention within the field and is moving onto wider markets. It’s been used a lot in social housing in England and Scotland, and to date it has won the Rushlight Energy Environmental Award, was Highly Commended in the Business Green Awards and been shortlisted for the Sustainability Leaders and the Energy Efficiency & Renewables Awards.

If you want to know more about Chopping and how it works, go to their website here: www.thechoppingcompany.com. If you want to buy one, they’re about £70, you can buy them online here: http://chop-cloc.com and you need a ‘competent person’ to install it (although apparently it’s not very difficult).

In strategizing to make our home greener we have been greatly guided by the hierarchy of retrofit action, see the image: firstly you try to use less energy, by switching things off, etc. Next, you need to try and use technology to try and make the very best use of the energy that you do use, such as insulating, draft-proofing and ‘Chopping’. The pinnacle of the triangle, the highest and hardest achievement, is working towards generating renewable energy (although this image puts the final achievement at the bottom of the image, suggesting perhaps the cut in energy usage?).



We try to buy A++ appliances wherever possible, and we’ve insulated most curtains. The windows still rattle, however, being Victorian sash windows, and the walls are paper thin and strangely seem to emit cold rather than radiant heat. People notice the slight drop in temperature when coming in (so it must be more than 2°C, scary). This makes it great in a heat wave, but terrible in a cold winter.

For now, I’m just massively enjoying the new warmth of the sun, not having to swaddle my little daughter in layers of clothes to keep her fragile little body warm, and sitting in the park occasionally without my shoes on…simple pleasures.

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