Radiators have evolved significantly over the past couple of decades, making them very much the heat emitter of the future, according to Chris Edwards.
With the rapid growth in the use of renewable energy, you might expect that the radiator is in danger of seeming outdated, but nothing could be further from the truth. Recent research commissioned by my company unearthed a large number of misconceptions about radiators that showed that it is our thinking that is behind the times, not the radiator.

In fact, the conclusion from research conducted for Purmo at the Helsinki University of Technology is that that radiators are ideally suited to use with the lower temperature heating systems powered by renewable technologies and are effective at delivering comfort and aesthetics too.

Over many years we have developed the belief that radiators must mean high temperatures. The research has shown conclusively that this is not so, confirming common practice in Scandinavia, where radiators have been successfully used with lower water temperatures over several decades. Radiators circulate system water and disperse heat into the room whether the heat source is a fossil fuel powered boiler or a renewable energy appliance.

The critical factor is the selection of the radiator to provide sufficient heat for the system water temperature. In reality, radiators don't need to be piping hot, they can routinely heat rooms using water temperatures of around 45 deg C, and in some applications, as low as 35 deg C, making them perfect candidates for use with renewable technologies. In fact, the research also showed that they can save around 15 per cent on energy bills over other forms of heat emitters.

This is partly due to the larger heat emitting surface, but also thanks to their speed in reacting to change, in particular in their ability to take advantage of solar gain, where other systems, such as underfloor heating, which has its own strength but is much slower to react to changing needs. Naturally, good insulation is also essential as heat conservation and recovery are a vital component of lower energy consumption in any property.

There is also a mistaken idea that a lower temperature system must mean a far larger radiator. Fortunately, radiator design has evolved to provide a far larger heat emitting area from a radiator of roughly the same size as its less efficient forerunners. This is a huge plus in a retrofit situation, installing new radiators is a like for like replacement, and also a bonus in new build as radiators need not take up too much valuable space.


Longevity of the system
The quality of the radiator is, naturally, important as it would be wasteful to have to replace cheap, poor quality radiators early in the lifecycle. Therefore, it is essential to ensure that models made from high quality materials are specified. They should also have a minimum 10-year guarantee to ensure the longevity of the system, which ought to be at least 25 years.

As well as lower long term running costs, in a refurbishment project, modern radiators represent excellent value for money in terms of their replacement cost. They cause little disruption and, once installed, are practically maintenance free. Even in new build projects, using radiators leaves you free to choose any type of floor construction or covering, whereas underfloor heating, although excellent in the right setting, can be problematic with some floor coverings.

In a residential setting, one of the prime considerations for any property is best use of space. An increasing number of commercial buildings feature glass walls or large windows and some forms of heat emitter can cause heat stratification or cold spots within the building. In this case there may be areas next to the window where it is not practical to site furniture.

Radiators score highly here, as the best location for them is immediately under the window. As heat rises from the radiator, the cold surface of the window forces heat back into the room, setting up a convection pattern and ensuring that the entire room is heated, right up to the window. All the available space can be maximised, especially in winter when seats and tables by the window are still popular in hotels, restaurants, and care homes; and even in offices, where daylight is always at a premium.

Where people are sedentary, in care homes and hospitals, where the elderly or infirm may sit for long periods of time, even heating is particularly important. With some forms of heating, the spread of warmth can be patchy, or in layers. Those who spend a large amount of time seated will notice that while their feet and knees may be comfortably warm, warmth has yet to reach shoulder or head height, so that genuine comfort heating takes far longer. Radiators, on the other hand, will raise the temperature to the desired level quickly and evenly throughout the room, without causing heat stratification.

As well as more conventional horizontal panel models, which are themselves now available in a wealth of different sizes, surface textures and colours, newer vertical models also allow the installer to locate radiators on narrow wall spaces or to create a focal point using the radiator as a piece of art. In cloakrooms, bathrooms, en-suites and kitchens, the designer can also choose from a range of heated towel rails, which provide towel warming and storage as well as ambient heat.

With the range and variety of styles available, radiators are equal to being used in almost any setting and with any heat source. If your client wishes to be as environmentally conscious as possible, it should also be borne in mind that radiators are 100 per cent recyclable too. When there's so much to learn about new technology, it's good to know that the tried and tested radiator still has a key role to play in the heating system of the future.

//The author is UK sales and marketing director of Purmo //