A: At Foundry, we recommend using a BTU heat loss calculator to accurately determine the heating requirements of your room before selecting a radiator. This calculator considers factors such as room size, insulation, window type, and external wall exposure to estimate the total British Thermal Units (BTU) needed to maintain a comfortable temperature. Once you know the required BTU output, you can choose from our range of cast iron, steel, or aluminium radiators that match or slightly exceed this figure, ensuring efficient and consistent heating. Our luxury cast iron radiators are particularly effective due to their high thermal mass, providing sustained warmth and complementing classic or contemporary interiors. If you need assistance interpreting your heat loss results or selecting the perfect radiator, Foundry Cast Iron's experts are available to guide you through the process for optimal comfort and energy efficiency.

A: BTU, or British Thermal Unit, is a standard measurement of heat output that indicates the amount of heat a radiator can emit in one hour. At Foundry Cast Iron, understanding BTU ratings is essential to selecting the right radiator to efficiently heat your space. A radiator with an appropriate BTU rating ensures optimal comfort by matching the heat requirements of your room size and insulation levels. Our expert team can help you calculate the correct BTU needed based on your specific environment and recommend high-quality cast iron, steel, or aluminium radiators that deliver consistent, effective heating while complementing your interior aesthetic.

Once you have your total BTU requirement, you can decide how to distribute that heat. Single vs. Multiple Radiators: If your room requires a high BTU (e.g., over 6000), you may want to install two smaller radiators on opposite walls rather than one massive unit. This provides a more even heat distribution and eliminates "cold spots." The Cast Iron Advantage: For period properties with high ceilings or poor insulation, cast iron radiators are often the best choice. Their high emissivity means they continue to radiate heat far longer than thin steel panel radiators.

Yes. It is always better to have a radiator with a slightly higher output than you need. You can always turn a radiator down using a Thermostatic Radiator Valve (TRV), but you cannot "force" a small radiator to produce more heat than its maximum capacity.

Absolutely. A modern new-build with cavity wall insulation and double glazing will retain heat much better than a Victorian terrace with solid stone walls. Our calculator allows you to factor in these variables for a more tailored result.

As a general rule, we recommend: Living Rooms & Dining Rooms: 21°C (70°F) Bedrooms: 18°C (64°F) Bathrooms: 22°C (72°F)