There is a reason for that. We tell you why radiators are installed under windows.
Why are radiators installed under windows?
The apartments and the interior architecture have evolved over time. However, when the craftsmen come to install the radiators, they place them in the same place: under the window. We don’t ask questions and we let them do it, but why are they installed there?
One of the reasons is that if the radiator was not placed under the window, the window glass would be extremely cold.
When the warm moist air in the house meets the cold side of the glass, the vapors liquefy and condensation occurs. Condensation can be damaging to your walls. It can create mold, damage joinery and cause unpleasant odors in the house.
When the radiator is installed under the windows, a “curtain” of heat is created. This prevents water vapor from condensing on windows or other surfaces in the home.
“In fact, under each window must be installed a radiator. If there are two windows in the room, we will place two radiators at a maximum distance of 30-40 cm from the wall with the glass. Placing the radiator under the window is a wise choice from another point of view: it’s a dead space and generally you can’t put anything else, such as furniture,” explains Thierry Chalençon, Expert in thermal insulation.
The right power
The power of a radiator is expressed in watts. It depends on the volume to be heated, but also on the type of room and the ideal temperature desired by the user. In a well-insulated home, it takes an average of 93 W/m3 to heat a bathroom to 24°C, 85 W/m3 for a living room to 22°C, 77 W/m3 for a kitchen to 20°C and 70 W/m3 for a room at 18°C. If the house is not well insulated, the power will have to be higher. In a room of more than 25 m2, it is better to install two to three radiators of lower power, rather than a single large one, in order to better distribute the heat.
With electric radiators, it is estimated that 750 W are needed to heat a space of 5 to 9 m2, and more than 1500 W for a room larger than 20 m2. With a low temperature model (electric or gas), it takes 70 W per cubic meter of room volume. With central heating (oil or gas), there are 50 W per cubic meter.
Cast iron, dense and heavy, offers excellent thermal restitution and preserves air quality, but it takes a long time to heat up. It is mainly used for central heating radiators. Cheap steel is used for basic convectors as well as radiant and radiant models. Without inertia, it heats and cools quickly. Like the latter, aluminum heats up and cools down quickly, but it is lighter and has better structural quality. Used for radiant or inertia radiators, it is often coupled with other materials for more performance: glycol oil for a fluid inertia model, ceramic, soapstone or volcanic stone for dry inertia. Lava stone offers a very high calorific value. It is the material that best accumulates heat, then releases it slowly and evenly. In addition, lava heaters are the least bulky of the inertia models. Soapstone accumulates a lot of heat in a small area. Beware of reconstituted steatite, based on a cement binder, which is much less efficient. As for ceramic, it is an excellent material for fluid inertia radiators. It restores the heat evenly and gradually.
Convectors, often nicknamed “toasters”, are the first generation of electric heaters. They remain inefficient and dry the air. They rise quickly in temperature, but do not restore any heat once extinguished. Their only advantage: the price. Radiant and radiant models produce infrared rays and provide comfort similar to the heat of the sun. Inertia radiators represent the new generation of heating emitters. They can be fluid inertia (they contain glycol or mineral oil) or dry inertia (steatite, ceramic, volcanic stone heating core, etc.). With the latter, it is the material itself that stores and releases the heat. Soft heat radiators consist of a cast iron or aluminum radiating front panel heated by a first resistor, and a stone or liquid heating core with a second resistor. The radiator does not exceed 70°C. The heat is very pleasant, homogeneous, and the air is not dried out. Storage models are made of refractory material to store a lot of heat and release it for a long time (up to 8 hours of heating once turned off). They can thus be operated during off-peak hours and switched off during peak hours, but they have the drawback of being bulky and heavy.
Today there are all kinds of radiators. The shape is chosen according to the available space and also the desired design. If, traditionally, horizontal models are installed in bedrooms and living rooms, a beautiful high radiator can also have the most beautiful effect. In the kitchen, where space is often limited, it is advisable to give preference to compact and vertical models. In the bathroom, the heated towel rail remains the ideal solution. For lofts or under a low window, there are “plinth” models, all in length and low in height.
There are now connected or “intelligent” radiators, which can be controlled remotely from a smartphone or tablet. Thanks to this very fine control of the temperature and the real-time monitoring of electricity consumption, the bills are even lower. Some models are able to memorize the rhythm of life of users, therefore to program themselves according to situations and even unforeseen events. Intelligently controlled radiators can save up to 45% energy. A smart thermostat can be installed on a non-connected radiator, equipped with functions for presence detection, window opening and closing, with indication of consumption, etc. These thermostats are also controlled remotely from a smartphone and allow electricity consumption to be adapted exactly to user needs.