Choosing a Radiator

Tuesday, 26 September 2017  |  Admin

While people want to make a house look good the main point of it is shelter. A crucial aspect of that shelter is to keep people inside warm when it is cold. However you need to be sure that you have the right type and amount of radiators.  

In this article we will look at various issues regarding how to determine the radiator requirement of a room and how to ensure that you have the right type of radiators, the right amount of radiators and to make sure that they are all running as efficiently as possible. 

  Hot stuff 

  Before you look at possible units for your house it is worth knowing how the level of heating is measured. The heat output is measured in British Thermal Units per hour (or BTU/h for short). There are online guides available that can allow you to calculate the amount of BTU/h that each individual room in your house needs.  

However when it comes to getting the radiators fitted and installed it is vital that you do so through a Gas Safe registered heating engineer or plumber as this will ensure that they are properly fitted, as energy efficient as possible and (more importantly) safe. 

A heating calculator is the quick and easy way online to learn more about how much output is needed to heat specific areas of the house and can give you a rough guideline when it comes to working out the energy needs of your home, allowing you to adjust the size and the amount of radiators according to the needs of each individual room. 

The calculation to measure the necessary output depends on the room- 

  • Lounge/dining area- Multiply cubic feet x 5 
  • Bedroom-  Cubic feet x 4 
  • Communal areas/ kitchens- Cubic feet x 3 
  • If the room faces north add 15% to the calculation 
  • If you have French windows add 20% 
  • For double glazing reduce by 10% (It is also worth checking online for other methods of energy efficiency to further reduce heating costs, such as insulation and sealing gaps in doors, windows and walls). 

Generally speaking you will not get a unit that exactly matches the calculation so it is often best to go with one that is slightly larger than what you need so that you can get a bit more heat if necessary.  

With rooms that are larger than 18 feet (6 metres) it is recommended that you have a number of units spaced out in order to spread the heat more evenly around the room. 

Heating controls can also make it easier to control and monitor the amount of heat that you use. 

Heat loss 

Another aspect to consider is the heat loss that can occur in a room. This can occur due to a number of factors such as the number of doors in the room, the size of the windows and the material that the room is constructed from. The measurements can be quite complex.  

However it is important to get it right because if the unit you choose is too large for the room then it will be less efficient and therefore more expensive to run in the long term.  

The ideal location 

The best place to position a radiator is in the coldest part of the room (usually below a window or an outside wall). On the surface this sounds obvious- if that part of the room is cold you want it to be warmed up! 

However there is another reason for this- the cold air from the coldest part of the room travels around. Therefore if you position your radiator effectively then you will get the maximum efficiency out of the radiator. 

Size matters 

A radiator will usually be around 300-700mm high and usually around 500-3000mm in length. For the most part larger radiators will be able to generate more heat. Therefore if possible you should look for spaces in your room where you can position a larger unit in order to ensure that the whole area can be properly heated. 

It is fair to say that in some cases having a larger unit is simply not possible. For example you may have a converted loft space that you have turned into a bedroom and there may not be room to put a large radiator there. If this is the case then putting heaters in the skirting can be a space saving alternative (while at the same time still ensuring that the room is properly heated). 

While this may sound obvious do not forget to mark out the area where the radiator is and ensure that it can be safely positioned there (ideally go for something slightly smaller than the space available to literally allow for a bit more wiggle room!) 

  Different types of radiator 

  Steel pressed flat single panel radiators- One of the first types of radiator to be fitted into people’s homes, these are very large and can take up quite a lot of space (as well as only providing radiant heat) 

  • Convector radiators- These were developed after the flat single panel with fins welded to the back. These fins meant air could move under and over, allowing for a more even spread of heat. Another benefit is that there are convector units that are smaller than the bulkier single panels. 
  • Double panel convectors- These are very powerful and give out a lot of heat. However they can also be very bulky. 
  • Compact radiators- A variation on the flat single panel. They are smaller and have grilles on the top as well as panels that hide a convector inside. One disadvantage is that they do need regular dusting as dust gets into the holes in the grille. 
  • Low surface temperature radiators- These are ideal if you have elderly relatives (for example some older people may not be as sensitive to heat and burn themselves without realising it) or young children as they are not overly hot to the touch while still heating the room.  eg Jaga Guardian LST, Jaga Cocoon LST, Jaga Tempo LST at


The material that a radiator is made from can also affect whether or not it is suitable for a room. Materials include- 

  • Cast iron- A lot of early Victorian models were made of cast iron. One of the problems with using this material is that it can take a while to heat up. On the other hand it does stay warm long after the heating supply is turned off so in some cases it may actually be an energy efficient option. 
  • Stainless steel- The advantage of stainless steel is that it doesn’t rust and is an efficient conductor of heat. Furthermore if you want the aesthetic style of cast iron it is possible to find models that mimic that look. However it is important to be aware that there are around 150 grades of stainless steel and some are more appropriate for radiators than others. 
  • Aluminium- A highly efficient superconductive material. They are also more responsive to thermostat changes and therefore give you more control over your heating. They are also light and easier to install than other types of radiator. 

All materials have their advantages and disadvantages. This is why it helps to discuss this with a heating professional so that they can tell you what type of material is best suited to the heating requirement of each individual room (it may be that one is better suited to one room more than another depending on the amount of insulation, number of doors and so forth). 

  The bathroom 

There are numerous options available for heating your bathroom. A heated towel rack is a great option for a number of reasons- having warm towels is often pleasant for you and your guests, while there is also the added space benefit of having those heat the room in lieu of a larger radiator.  

Furthermore a number of Plumbhouse bathroom radiators and towel racks are pre-supplied with an anti-corrosion thermal transfer fluid (this ensures heat performance and durability). 

If you have a smaller ensuite unit then mirror radiators are also available as a space saving option. In terms of heat requirement for the room itself these smaller items ensure that the heat is focused in the areas that are required for comfort. 

  The kitchen 

The kitchen is another area where space is at a premium and it may not always easy to fit larger radiators in there. The kind of unit you choose for your kitchen will depend on the size of the room. A slim and tall vertical radiator is ideal for people who have smaller kitchen units in their house.  

Given that you are likely to have an oven in one part of the room it is best to have a radiator away from there (because as stated before the cold air travels further and heats the rest of the room more). 

You also need to consider whether you necessarily need a radiator installed (for example if you have an aga in the kitchen). 

The bedroom 

When it comes to warmth the bedroom is where it is vital to get heat right. If the room is too cold or too hot then you can struggle to sleep (this can contribute to stress and health problems in the long term.)  

With smaller bedrooms flat panel or tubular models are often best as they can heat the room without taking up too much space. However it is fair to say there are plenty of larger units available for larger bedrooms as well and it should also be emphasised that you can still get stylish looking larger heating units as well. As with any designer item it is worth looking through the various options and deciding what is appropriate for the space you have. 

Dining areas/communal areas 

In this instance smaller units are probably best in order to maintain cosiness without standing out too much. Heated skirting may also be an option if the dining or communal area is quite small and you want heating around the room that is reasonably even (although if you can fit in a larger unit then you are likely to get a better overall amount of heat throughout the room). 


In simple terms there are a few basic considerations to keep in mind when choosing radiators for each room- the position of the radiators is important, as well as the amount of them and the material they are made from. 

It is also worth considering- 

  • The size of the room- Making sure that you have the right sized unit/amount of units that is appropriate for keeping the room heated. 
  • Energy efficiency- If the radiator is too large then you are wasting energy. It is also worth insulating rooms as much as possible in order to reduce the amount of energy you need in order to heat a room (and to save you money in the process). 
  • Effective calculation- A heating calculator makes it easier to gauge the amount of heating you need for specific rooms (for example you need different levels of heating for a bathroom then you do for a kitchen). 
  • The right kind of radiator- Some models are more efficient than others. If you have an older single pressed model then it is worth looking at newer models because these are more energy efficient and will save you money in the longer term (it is also worth looking for grants in your local area that could help you save money on getting newer, energy efficient models and other methods of insulating your home to reduce energy costs). 
  • Installation- Remember to bleed your radiators regularly as well (there are videos online that can help with this).