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Are Cast Iron Radiators Efficient?

Cast Iron Radiators are becoming increasingly popular in modern times.

In fact Cast Iron Radiators have become one of the most common radiators in homes today, in this article we will discuss why that is with a focus on their energy efficient benefits that a proving why these radiators are so popular in modern times.

But Why Are More People Choosing Cast Iron Radiators?

Cast Iron Radiators are a great choice for many reasons, but one primary reason is their energy efficiency, not only that they are incredibly durable and last for years.

This makes them great long term investment, you will not have a to repeat purchase in the next 5 years like some modern heating alternatives.

These radiators have been around for centuries and they have proven their worth and still today they can compete with all modern heating systems available.

woman in an orange top holding an energy bill leaning on a tall white cast iron radiator

So what makes Cast Iron Radiators so energy efficient? What is their secret to their counterparts?

Cast Iron Radiators have a high inertia level, and high carbon content.

Cast iron is heavier and denser than steel. It will therefore retain heat much longer after your boiler has shut down. The cast-iron radiator cools down slowly, whereas a steel radiator loses heat more quickly. This means that a room will cool much faster.

Steel emits a large amount of heat quickly, but then will lose heat quickly when your energy heating source has been switch off.

With a Cast Iron Radiator, the heat is retained in the Cast Iron for much longer as Cast Iron has a much higher conductivity than their steel radiator alternatives.

Also cast iron has a higher carbon content, which allows it to hold heat longer than steel. The high content of carbon allows the heat to spread evenly through the cast-iron surface, which makes it a more efficient radiator.

In simple terms, what this means for your home is that heat is transferred from the radiator's surface to the room much more efficiently than with steel.

Cast iron will emit an ambient warmth over a longer period than steel, still heating your room after the heating source has been switched off.

Don’t believe us? Check out this YouTube video below that demonstrates the heating and cooling cycle of Cast Iron Radiators vs Steel.

Click here to see the Youtube Video

Does my boiler provide better energy efficient heating with cast iron radiators?


Cast iron radiators will help your boiler because they heat the water more efficiently than modern steel radiators.

Cast iron radiators are more energy efficient because they can hold heat longer and better.

Are cast iron radiators more efficient in a modern building?

Cast iron radiators used to be seen as only suitable for period properties with large rooms and high-ceilinged rooms.

However, a growing number of designers and architects are specifying them for new homes due to their efficiency and the versatile design options, basically any length or width is available from the likes of Carron Radiators or Arroll Radiators.

Modern homes can now enjoy the efficiency of cast iron radiators on central heating systems as we strive to use energy more efficiently.

Also with the rise in Electric Heating Elements, these can easily be implemented on your new Cast Iron Radiators, or you can adapt your current ones with a DIY Heating Element Kit.

So this means all your Cast Iron Radiators can now use energy efficient electric energy rather than dated gas central heating systems.

woman in an green jumper feeling the heat being produced from a white cast iron radiator

An Electric Cast Iron Radiator for Energy Efficient Heating? Is it possible?

Of course! Our electric cast-iron radiators provide energy-efficient heating, by using a smart meter.

Smart thermostats have risen in popularity in recent years and this allows flexibility between your radiators within your home, then saving you money.

Heating radiators between rooms this allows you to turn off rooms that don't need heating during the day. Each heating element is thermostatically controlled all from your smartphone app, saving you money and energy.

You can now set your Cast Iron radiator temperature in your living room, in the car whilst you’re diving back to the house. How is that for convenience?

You can now just set your Cast Iron Towel radiators in the bathroom to heat the electric elements in summer without heating up the rest of your house, again saving on your pocket.

The heating can also be turned off in the bedrooms and living rooms during the day.

Electric cast iron radiators offer you flexibility, convenience, energy-efficiency and most importantly saving you money.

Cast iron radiators will they work well with Air or Ground heat source systems?

Popularity of renewable energy sources and new greener heating systems instead of gas boilers has increased in recent years.

You have probably heard of them, Air or Ground Source heat pumps.

Cast iron radiators have excellent conductivity and density, making them ideal for low temperature heating systems and these new greener heating systems.

Cast iron radiators are ideal for today's energy-efficient and renewable heating systems, as they use the heat from the air or ground to heat your home.

As Cast iron radiators retain their heat much longer than steel radiator, what is means is that the heat going back into the system’ is much hotter than with the use of steel, thus making the heat pump much more energy efficient.

As Steel radiators will heat up quickly and then lose their temperature, which makes the heat pump have to work harder in order to maintain the temperature, mean more cost to keep the pump running which is what we are trying to avoid.

Cast iron radiators retain heat longer. When the water returns from the natural source, it is hotter and can be used more efficiently by the heat pump.

All in all, Cast Iron Radiators make a great choice to use with modern air and ground heat pumps for your home.

woman feeling the heat on the top of a cast iron radiator with a jumper on

3 Key Features that make Cast Iron Radiators Energy Efficient

Cast Iron Offers Excellent Heat Retention

Cast iron radiators are more heat-resistant than steel or aluminium.

Your radiators will radiate heat even when your boiler or thermostat is turned off.

This keeps your home warm. Cast iron radiators take longer to heat than other materials, but this problem can be overcome by using a thermostat that is programmed to heat your Cast Iron Radiators around 10 to 15 minutes before you want to feel full heat output from your radiator.

Cast iron is also a good heat-retention material and has a high conductivity. This means that the boiler doesn't have to work as hard because the water temperature returns to the boiler stays much higher.

Consistent and energy efficient heat

Cast iron radiators are highly efficient in providing constant heat due to their density and carbon content.

They take longer to heat a room but once they are running, they produce a steady and efficient heat that will warm your house comfortably and gently.

The heat from steel and aluminium radiators is very intense, resulting in hotspots throughout the room and the need for regular temperature adjustments.

They work well with Air and Ground Heat Source Pumps

As Cast iron radiators retain heat for longer periods of time than steel. When the water returns from the natural source, it is hotter and can be used more efficiently by the heat pump.

This means that the heat pump doesn't have to work as hard because the water temperature returns to the heat pump stays hotter for longer, returning to the heat pump with more heat.

white table with a green plant and flower pot on the table sitting in front of a white cast iron radiator

In Conclusion why Cast Iron Radiators make a great energy efficient choice

Cast iron radiators offer a fantastic choice for homeowners seeking an energy-efficient heating solution.

Their unparalleled durability and longevity make them a wise long-term investment, as they can continue providing reliable warmth for decades with minimal maintenance.

Equally important, the exceptional heat retention properties of cast iron enable these radiators to operate at lower temperatures, resulting in significant energy savings that translate into lower utility bills.

Furthermore, the classic, timeless aesthetic of cast iron radiators seamlessly integrates with a wide range of interior design styles, ensuring they enhance the visual appeal of any space.

When considering the combination of energy efficiency, cost-effectiveness, and timeless style, it becomes clear that cast iron radiators are an great option that homeowners would be wise to consider for your heating needs.

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