Now that winter is approaching, we are looking for ways to keep our homes warm without spending a fortune on heating. Given the increase in the price of electricity and gas, this may seem complicated, but there are certain habits that can help us achieve our goal: installing seals on doors and windows, placing aluminium panels behind radiators to reflect heat into the room. How about turning off the heating in rooms that are not in use and closing the door?
At first glance, this may seem like a good idea, because if we are not in a room, why heat it? However, several experts agree that this measure does not help to save on heating, but rather the opposite. The problem is that the walls, floor and even the furniture in that room become very cold, and this cold is gradually transmitted through the structure and the air to adjacent rooms, even if the doors are closed. As a result, rooms where the radiators are on lose heat more quickly.
Experts are very clear on this issue: ideally, the temperature in rooms should never fall below 12 °C, although the ideal temperature is around 16 °C. Now let’s imagine a house where the radiators in an unused room are turned off and the temperature quickly drops to 10 °C or even lower. It may seem like nothing is happening, but in reality, cold air seeps in under the doors or through the walls, especially if they are more insulated. As a result, the rest of the house cools down and the radiators have to work twice as hard. Several studies have shown that energy consumption increases by between 7% and 12% when there are large temperature differences between rooms in the house.
However, if you are away from home for several days, it makes sense to turn off the heating, although this depends on how long you will be away. If it is only two or three days, it is not advisable to turn off the heating completely, as it will consume more energy to recover the temperature. On the other hand, if we are away for a week or more, we can turn it off, although in cold climates it is advisable to leave it at 12-14 °C to avoid humidity problems.
It is important to note that reheating a house that has dropped to 8-10 °C can require several hours of continuous operation at maximum power. This energy peak is usually higher than the accumulated consumption of maintaining a moderate temperature during the days we are away. Another aspect that we often overlook is that cold rooms accumulate humidity. Cold air retains less water vapour, so it tends to generate condensation on windows, walls and ceilings. This humidity, even if it is located in a single room, ends up spreading throughout the rest of the house.
As a result, mould appears, fungi and bad odours proliferate, and damage to textiles and furniture can even occur. In addition, humidity increases the sensation of cold because humid air transfers heat better. In other words, a damp room requires more energy to heat, which again translates into an increase in your electricity or gas bill. In short, experts agree on certain ranges that are considered optimal for both health and energy efficiency during the coldest months of the year: 17 °C in bedrooms at night, 19 °C in living rooms and rooms in regular use, 22 °C in bathrooms while they are in use, and 16 °C in unoccupied rooms.
Finally, “it is estimated that approximately 50% of homes are poorly insulated, many of them built before 1980, when no thermal insulation was required. A poorly insulated home (e.g. with an E energy label) can require almost ten times more energy than a home with an A label. In addition to improving comfort, good insulation can reduce energy consumption by up to 60%, which translates into savings of up to €1,000 per year in air conditioning, depending on the area and type of home. Each Spanish family spends, on average, approximately €1,000 on natural gas heating and €2,000 on electric heating (estimated calculation). Up to 30% of this consumption (more than €300) and energy can escape through the walls, ceilings and floors of poorly insulated homes,” says Leroy Merlin.
In short, although intuition tells us that turning off the radiators in a room we do not use is the most logical thing to do, the physics of heat and the behaviour of homes show that consumption can increase if a thermal imbalance is created. The key to saving energy during the winter months is to regulate the temperature intelligently and improve insulation.
