Winter is around the corner. Days are drawing shorter, the temperature outside is dropping and with it comes the season of squabbling over the central heating. Households are already drawing dividing lines between people who prefer a constant toasty warmth and those who think that the best option is to simply sling on another sweater and brave it out until bedtime.
Battles over the thermostat might sound mundane on an individual level, but countrywide the impact of our heating is huge. In 2013, 85 per cent of all domestic energy use in the UK went towards heating our homes and water, equivalent to burning 37 million tonnes of oil. And almost all of that heating is provided by burning natural gas, which is why reducing the energy we use to heat our homes is such a huge part of the UK’s 2050 net zero carbon goals.
Despite this, lots of us are clueless when it comes to the most efficient way to heat our homes. Should we crank the heating all the way up and ride that warm haze for the rest of the day? What’s the best way to distribute heat easily through the whole house? And when should I leave the central heating altogether and opt for a space heater?
To bring a little clarity to these heating dilemmas, I spoke to two heating experts to answer some of our biggest heating conundrums and perhaps diffuse a few of those thermostat-induced arguments.
Should I crank up the thermostat to heat the house quickly?
If you’re particularly chilly, it might be tempting to turn the thermostat way up in the hope that your boiler will work harder to reach that higher temperature, and dial it back down once you’ve got to your actual desired temperature. A little like slamming down the accelerator to catch the next traffic light before it turns red.
But in most cases this isn’t going to make your place heat up any faster. “It doesn't work like that, it will get to 21C at exactly the same rate even if [the boiler] is on its way up to 30C after,” says Jenny Crawley at the University College London Energy Institute. Generally-speaking, the boiler will continue to work at the same rate until the house has reached the temperature set by the thermostat, then it’ll turn off.
There are a couple of ways to get heat more quickly, Crawley says. You could invest in bigger radiators which are better at heating up larger rooms or you can turn up the temperature of the boiler, which would increase the temperature of the water delivered to the radiators. But fiddling with the boiler temperature isn’t particularly convenient so once you’ve found a setting you like, you’re much better off sticking with the thermostat and getting a cup of tea while you wait for the place to warm up.
If I’m only in one room, is a space heater better than heating the whole house?
Unlike central heating, space heaters typically use electricity to heat a very small section of a room. If you’re in a large house and you’re really only using a small corner of it, you might end up using less energy overall if you’re using an electric space heater, says George Bennett, one of Crawley’s colleagues at the UCL Energy Institute.
The problem is that electricity is much more expensive than gas, so you would have to be using considerably less heat for it to make sense to use a space heater rather than your central heating. If you’re likely to need heat in more than one room, you’re much better off using your central heating instead.
Can I capture some extra energy from the Sun to heat my room?
Even in the winter, the Sun provides us with a free source of added heat energy. “What happens is the Sun comes in and heats the walls and the floor, and that heat can be stored and let out nice and slowly during the day,” says Crawley. If your house is chilly, it makes sense to open up the curtains and try and let as much sunlight in as possible.
Passive housing is an architectural movement that seeks to make the most of the environment in order to minimise the amount of energy used to heat or cool the building. These kinds of houses are often made of out concrete, which are able to store a lot of heat and release it slowly, but in the UK houses tend to be coated in plaster which reduces their ability to capture the Sun’s energy.
Should I shut doors to trap heat or let heat circulate the house?
The hot and cold spots of any house will change depending on lots of factors. If you haven’t got insulation in your loft, the top of your house might be cooler than the bottom. If you’ve got a particularly draughty front door, then it’s likely that the downstairs will be cooler.
The trick is to try and conserve heat in the spaces it’s being generated – as long as that doesn’t make the room too stifling. Crawley gives the example of an office. The computer will be kicking out a certain amount of heat, and so will your body, so it makes sense to shut the door and trap that heat in the room if you’d be heating up anyway.
The only thing you want to be mindful of is ventilation, as you don’t want the room getting too stuffy. Bennett points out that the Germans have a word for a quick blast of cold air to freshen up a room: [/i]Stosslüften[/i] which roughly translates as “shock ventilation”. Practising a little bit of [/i]Stosslüften[/i] every now and then might help your room feel a little bit less stuffy after a day with the door closed.
What temperature should I be setting my thermostat at?
According to the energy company Ovo most of us set our thermostats to 20C over winter, while the actual average room temperature is roughly 18C. If you’re looking to make your heating as energy efficient as possible then you want to think about what the average temperature your house is over an entire day – that’s more important than whether you have spikes of heat or whether you keep the heating on for the entire day. “The [24-hour-period] with the lower average temperature is going to use less energy,” says Crawley.
What’s the easiest way to make my house warmer?
Fiddling with your central heating is only going to take you so far. “If you get a new boiler, your heating bill may change by ten per cent. If you live in a draughty old home and you insulate properly, you could reduce the heat loss from your building by 20 to 30 per cent,” says Bennett. That’s why the UK government is currently offering grants for homeowners to install energy-saving improvements like triple-glazing and heat pumps.
But there are slightly more temporary ways of keeping warm. Slipping on a pair of socks or slippers and avoiding cold floors can help increase your perception of heat. One study from South Korea found that people wearing warming socks in bed tended to fall asleep faster and stay asleep longer than those who went without bed socks. This partly explains why people in the UK are so obsessed with carpet, Bennett says. Perhaps pulling on that extra jumper isn’t such a silly idea after all.
Matt Reynolds is WIRED's science editor. He tweets from @mattsreynolds1
This article was originally published by WIRED UK
