Cast Iron Radiator Specifications

Cast iron radiator	Section	Section Height	Section Depth (distance radiator protrudes from wall)	Section Length (as measured along the wall)	Distance from inlet/outlet pipe centre to floor	Distance from inlet/outlet pipe centre to skirting board	Internal volume (section)	Empty weight (section)	Section output (ΔT=60°)	Section output (ΔT=60°)
2 Column 650mm	Middle	572mm	84mm	66mm	110mm	42mm	0.80L	4.1kg	110 Watts	375 BTUs
	Leg	650mm						4.4kg
2 Column 750mm	Middle	672mm	84mm	66mm	110mm	42mm	0.90L	4.6kg	133 Watts	454 BTUs
	Leg	750mm						4.9kg
3 Column 450mm	Middle	376mm	120mm	61mm	110mm	60mm	0.90L	3kg	75 Watts	256 BTUs
	Leg	450mm						3.45kg
3 Column 645mm	Middle	576mm	120mm	61mm	110mm	60mm	1.10L	4.5kg	105 Watts	358 BTUs
	Leg	645mm						4.9kg
3 Column 745mm	Middle	676mm	120mm	61mm	110mm	60mm	1.20L	4.6kg	118 Watts	402 BTUs
	Leg	745mm						5kg
4 Column 18"	Middle	382mm	150mm	61mm	115mm	75mm	0.60L	3kg	78 Watts	266 BTUs
	Leg	460mm						3.4kg
4 Column 26"	Middle	582mm	150mm	61mm	115mm	75mm	0.80L	4.4kg	116 Watts	396 BTUs
	Leg	660mm						4.8kg
4 Column 30"	Middle	682mm	150mm	61mm	115mm	75mm	0.95L	5.2kg	134 Watts	457 BTUs
	Leg	760mm						5.6kg
4 Column 32"	Middle	725mm	162mm	58mm	132mm	81mm	1.05L	6kg	152 Watts	518 BTUs
	Leg	813mm						6.4kg
5 Column	Middle	300mm	175mm	47mm	85mm	88mm	0.60L	3kg	68 Watts	232 BTUs
	Leg	340mm						3kg
6 Column 620mm	Middle	560mm	220mm	52mm	105mm	110mm	1.70L	8.9kg	139 Watts	474 BTUs
	Leg	620mm						10.3kg
9 Column	Middle	300mm	340mm	60mm	76mm	170mm	1.15L	7kg	130 Watts	443 BTUs
	Leg	340mm						7.4kg
Baron 460mm	Middle	405mm	125mm	76mm	102mm	63mm	0.90L	5kg	62 Watts	211 BTUs
	Leg	460mm						5.4kg
Baron 610mm	Middle	555mm	125mm	75mm	102mm	63mm	1.00L	7.2kg	83 Watts	283 BTUs
	Leg	610mm						7.6kg
Bohemia 640mm	Middle	540mm	230mm	86mm	140mm	115mm	2.85L	10.2kg	110 Watts	375 BTUs
	Leg	640mm						11.4kg
Cherub	Middle	750mm	210mm	62mm	110mm	105mm	1.90L	13.9kg	143 Watts	488 BTUs
	Leg	800mm						15.9kg
Count 640mm	Middle	590mm	175mm	63mm	100mm	88mm	1.80L	8.4kg	108 Watts	368 BTUs
	Leg	640mm						8.8kg
Duchess 590mm	Middle	540mm	170mm	70mm	110mm	85mm	1.60L	8.3kg	110 Watts	375 BTUs
	Leg	590mm						8.7kg
Duchess 780mm	Middle	730mm	170mm	70mm	110mm	85mm	2.00L	11kg	141 Watts	481 BTUs
	Leg	780mm						11.4kg
King 470mm	Middle	418mm	250mm	79mm	110mm	125mm	1.45L	7.4kg	105 Watts	358 BTUs
	Leg	470mm						7.8kg
King 570mm	Middle	518mm	270mm	79mm	110mm	135mm	1.60L	8.6kg	130 Watts	443 BTUs
	Leg	570mm						9kg
King 670mm	Middle	618mm	270mm	79mm	135mm	135mm	1.90L	11.6kg	155 Watts	529 BTUs
	Leg	670mm						12.2kg
King 768mm	Middle	708mm	270mm	79mm	110mm	135mm	2.00L	12.5kg	178 Watts	607 BTUs
	Leg	768mm						13kg
King 970mm	Middle	912mm	270mm	77mm	113mm	135mm	2.80L	16.5kg	245 Watts	835 BTUs
	Leg	970mm						17kg
Prince 750mm	Middle	680mm	150mm	72mm	113mm	75mm	1.75L	6.4kg	113 Watts	385 BTUs
	Leg	750mm						6.9kg
Princess 560mm	Middle	535mm	190mm	77mm	118mm	95mm	2.00L	8kg	110 Watts	375 BTUs
	Leg	560mm						9kg
Princess 760mm	Middle	735mm	190mm	80mm	118mm	95mm	2.60L	11kg	151 Watts	515 BTUs
	Leg	760mm						12kg
Princess 810mm	Middle	785mm	190mm	80mm	118mm	95mm	2.80L	12kg	180 Watts	614 BTUs
	Leg	810mm						13kg
Queen 510mm	Middle	445mm	210mm	80mm	105mm	105mm	1.70L	7.2kg	97 Watts	331 BTUs
	Leg	510mm						7.6kg
Queen 760mm	Middle	701mm	210mm	77mm	105mm	105mm	2.40L	11.6kg	152 Watts	518 BTUs
	Leg	760mm						11.8kg
Rococo 950mm	Middle	900mm	120mm	75mm	108mm	60mm	1.30L	11.7kg	120 Watts	409 BTUs
	Leg	950mm						12.1kg
Royale 760mm	Middle	685mm	175mm	72mm	118mm	88mm	2.20L	9.3kg	132 Watts	450 BTUs
	Leg	760mm						10.2kg
Viscount 595mm	Middle	540mm	175mm	66mm	110mm	88mm	1.50L	7.5kg	99 Watts	338 BTUs
	Leg	595mm						7.9kg
Viscount 780mm	Middle	725mm	170mm	66mm	110mm	85mm	1.80L	9.6kg	134 Watts	457 BTUs
	Leg	780mm						10kg
Viscount 980mm	Middle	925mm	175mm	66mm	110mm	88mm	2.10L	12kg	168 Watts	573 BTUs
	Leg	980mm						12.4kg

To calculate the heat output needed for a room;

Use Castrads' Heat requirement calculator

Find the volume of the room by multiplying the width x length x height in metres. The following lethods can then be used to calculate an approximate value of the heat loss for that room based on the voilume in cubic metres:

• For downstairs lounges and dining rooms multiply by 50
• 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 increased accuracy the following factors should be added into the calculations

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 will give you the required heat output in Watts. To convert heat outputs to BTU multiply the Watts figure by 3.41. For guidance on installing your Castrads cast iron radiator please download the Help Sheet.

Cast iron radiator sizing figures quoted here are given in good faith and are true to the best of Castrads' knowledge. Actual heat requirements for a given room can vary. The heat output of a radiator can also vary according to the paint finish and draftiness of the room.

Length of a radiator is the length of a section times the number of sections plus 30mm. This allows for the extra length of the end bushes. Add a further 90mm, or 120mm in total (number of sections * length per section + 120mm) to obtain inlet/outlet pipe centre distances. This allows for 45mm between the end of the radiator and inlet/outlet of the valves at each end. Tolerance on these dimensions is +/- 4% and depends on the batch of radiator and the type of valve. Maximum working pressure for all Castrads' cast iron radiators is 90psi / 6 bar.

What does delta T mean?

The delta (Δ) T value is difference between the temperature of the water circulating through a central heating system and the ambient temperature of the area being heated. For domestic ventral heating systems the temperature flowing around a central heating system is often around 80°C, with the desired ambient temperature of the house around 20°C. The Delta T value is therefore 80-20 = 60.

Correction factors

If the difference in temperature between the circulating water and the room temperature is less than 60° C, multiply the number of sections of cast iron radiator by the following correction factors:

55°, 1.11;

50°, 1.28;

45°, 1.43;

40°, 1.67;

35°, 1.95;

30°, 2.36;

25°, 2.96;

20°, 3.91;

15°, 5.6

2 Column cast iron radiators really are higher output than 3 Column cast iron radiators of the same height. Each column in the 2 Column cast iron radiator is of larger circumference than those of the 3 Column cast iron radiator, so have a greater surface area.

Instead of Castrads cast iron feet , 5 Column cast iron radiators may be stood on blocks of wood, eg 20mm thick x 40mm wide x 160mm long. Castrads doesn’t supply these, but if you supply them yourself it eliminates the need for wall stays. It also reduces the overall height of the cast iron radiator from 340mm to 322mm including the 20mm wooden blocks.