Choosing an Aluminum Radiator for a 25 sq m Room with a 12-Rib Cast Iron Radiator

I intend to replace a cast iron radiator with an aluminum one. Currently, I have a 12-rib cast iron radiator, a room of 25 sq m, tight plastic windows, walls and insulated ceilings. I keep the temperature on the stove at 60 degrees. Unfortunately, it is difficult for me to heat this room with such a temperature on the stove.
Which aluminum radiator do you recommend using and how much space does it need along with the accessories?

Here you have a calculator: http://www.purmo.com/pl/produkty/calculator.htm

12 ribs per 25m2 is a bit too little. At least 20 ribs. The longer radiator (e.g. 20 fins) must be cross-connected, i.e. the supply on the opposite side of the return, if the radiators are side-fed. Buy a radiator with more fins

What all this for. I have 10 S-130 ribs in 19m2 - the equivalent of a T-1 (flat in a block of flats, 6th floor, theoretically moderately insulated, windows leaky from the People's Republic of Poland) and it is often overheated and practically needs to be screwed on all the time. The supply temperature rarely exceeds 60 degrees (with greater frosts) and 70 degrees is already in a really harsh winter (theoretically the maximum is 80 degrees). In general, one thing is the temperature on the stove and the other is the flow through the radiator. It may be that, for example, the supply water is hot (e.g. 70 degrees) and the radiator heats only slightly with the top, and the bottom is cold at all, because there is poor flow. Maybe it is worth increasing the flow through the already existing radiator and the number of fins will be sufficient (by the way, for me the supply and return twig is only 3/8 '' in diameter). And is the heating pump or gravity? With gravity the flow is always smaller (despite the larger diameter of the pipes) and more fins are always given than with pump heating.

101pawel wrote:

Assuming you have this room insulated reasonably well, use about 80 W / m? - this gives the required power of a set of about 2000 W, which will be around 14 to 16 ribs. So that you do not think too much, - buy 16 pcs.

I am considering a combination of 2 10-rib radiators type G 500 F KFA 789-100-44



After shortening the current twigs (0.5 inch), I will have a usable space of 180 cm
2 radiators is 160 cm - so there is about 20 cm for the accessories. Is it enough and what accessories do I need to purchase?
There must be a thermostatic head and shut-off valves. Is 20 cm enough for this equipment?
How many cm is needed to connect both radiators?
Thermostatic heads are in the price range from 40 to 200 PLN - how do they differ?
Is it worth combining with a cross connection? The extra 0.5 inch tube under the radiator looks boring

What about the rest of the installation?
If it is supposed to be the only new one among the old ones, you will not be too warm.

It all depends on whether the installation is pumping or gravity. You didn't write this. The radiators are screwed from the inside with special radiator nipples "to the forehead" and you do not know the radiator connection. If you are on gravity, then there must be a cross connection, otherwise the radiator will only heat up to half its width, and then it will be cooler

The installation is pumped, so there will be no problem.

More than one was surprised.

20 ribs will be too much for this room, the more that the aluminum ones are more efficient than the cast iron ones. Even the 16 ribs proposed in one post will be too many.

I have 20 aluminum fins and it is much warmer than with cast iron. There were no problems with the replacement because the spacing of the twigs at the cast iron and aluminum radiators is the same.