- How big should my cast iron radiator be?
- I need my radiator to be a certain length, how many sections do I need?
- What is the maximum size of radiator I can have?
- Why do I need to specify whether the radiator is going upstairs or downstairs?
- Are cast iron radiators as efficient as modern radiators?
- Can I replace a modern panel radiator with a traditional cast one?
- What is the maximum operating pressure of a cast radiator?
- What is a section and what’s a column?
- What’s the difference between powder coat and spray painted finishes?
- Is Pewter just a primer?
- I’m buying a large radiator, what do you mean by extra leg sections?
The size of your traditional cast iron radiator depends on the size of the room it is intended to heat, how well insulated the space is and what the room is used for. Living rooms and bathrooms should be warmer than hallways and kitchens for example. The easiest way to calculate your heat requirement is to use Castrads’ heat requirement calculator.
Heat output is measured in Watts or British Thermal Units (BTUs). To calculate the approximate heat requirement of a room, take the volume (width ´ length ´ height) in metres and multiply this figure by 50 for lounges and dining rooms. For downstairs bedrooms, halls and kitchens multiply by 40. For upstairs lounges and dining rooms multiply by 40. For upstairs bedrooms, multiply by 35. For upstairs kitchens, multiply by 30. For downstairs bathrooms multiply by 90, for upstairs bathrooms multiply by 75. For rooms facing North add 15%. For French windows add 20%. For double glazing deduct 10%. For a very cold climate such as windy high altitude locations, add 10%. This gives you an approximate guideline in Watts. To convert this into BTUs, simply multiply the number of Watts required by 3.41.
If the distance that you have is between two pipes, you must first of all subtract 120mm from that length to allow for the valves and end bushes. This will give you the length of the radiator. Take that length and divide it by the length per section of your chosen cast iron radiator model, given on Castrads’ technical data page. Round that to the nearest whole number to find the number of sections you require. You should then multiply the number of sections by the section length and add on the 120mm, just to be sure that you have not exceeded the distance between the pipes.
There is no maximum length of radiator, however cast iron radiators that are longer than 1.2m or heavier than 170kg must be must be delivered partially disassembled to be reassembled on site. Castrads does not sell oversize radiators online to avoid the complications that arise with delivery, please call on 0161 2970015 if you require an oversize radiator. On site assembly will require a rented assembly tool. The assembly tools are engineered specifically for Castrads and are not available commercially. The tool costs £80, with a £50 deposit refundable upon return of the tool to Castrads. Castrads provides free telephone support to customers assembling at home as well as an in depth advice sheet tackling all the common issues.
Traditional cast iron radiators are extremely heavy. Getting them up stairs can be extremely difficult, so for this reason Castrads sets a weight limit of 140kg on radiators that are to be transported up flights of stairs and 170kg on radiators that are to be installed on the ground floor. Of course Castrads can and do supply radiators that are larger than this, but The Company accepts no liability for damage sustained during manoeuvers. Please call on +44 (0)161 2970015 for enquiries about oversize radiators.
Yes. They work on exactly the same principle as modern radiators. Cast iron radiators usually have a larger internal volume, so they take a few more minutes to warm up. This also means that they stay warm well after the boiler has been turned off.
Absolutely. The radiators are supplied as a sealed unit, complete with bleed valve, blanking bush and ½” reducing bushes. Castrads also supplies a comprehensive range of traditional manual and thermostatic radiator valves to complement the radiators. All valves are standard 15mm output.
The maximum recommended working pressure for Castrads cast iron radiators is 90 pounds per square inch (psi). Most systems never exceed 45 psi. Very tall buildings, eg 10 storeys may have 90psi at the lowest level.
Spray painted finishes are carried out at Castrads’ HQ in Cheshire. Our expert finishing technicians use industry leading spray booths to paint each radiator to the customer’s requirements. Sprayed finishes allow the naturally pitted surface of cast iron to show through.
Cast iron radiators finished in spray paint will be ready for dispatch 7 days from the date an order is confirmed (so long as the paint is in stock).
Powder coat is applied as a free-flowing, dry powder. The coating is applied to an electrostatically charged cast iron radiator and is then cured under heat to allow it to form a tough outer shell.
Powder coating gives a smooth finish, so the rough cast iron is completely covered by a thick plastic skin. Castrads has a well established partnership with a local powder coating specialist. Powder coated finishes may take up to 16 days from confirmation of an order to date of dispatch.
See cast iron radiator finishes for more information
A resounding no! Pewter is a Cromadex paint with 30% gloss. It is free because we sell a lot of it.
Pewter is a neutral colour that suits all interiors. Unlike white or black, which can both dominate a room and reduce the contrast between low and highlights, pewter emphasises the patina of the radiator while remaining fairly understated.
It is the colour of the cast iron radiators in the company director’s house.
Cast iron radiators are very heavy. In order to better distribute the considerable weight we will assemble the radiators with a leg section either end of the radiator, and one or two leg sections equally spaced through the middle of the radiator. We will always ask our customers to check that this will not leave an unbalanced aesthetic in the house, however if you specifically do not want extra leg sections please do mention this when ordering.
Cast iron radiator schematic with excess internal legs for weight distribution