If i remove a radiator in the living room will there be a cold spot?

[SJnotsure]

Hi,
We currently have 3 old radiators in our living room, the room feels cold in winter and radiators take ages to get warm, system has been power flushed and new pump fitted, so want to replace the radiators. The room is 5.7 x 4.9m x 2.5m but heat vents upstairs to a landing with no radiator. BTU calc's from different website sites suggest anything from 7500 - 10,000 ish. Someone suggested adding an extra 0.5kw to cover the heat loss to the landing.

The room has radiators on two of the walls and one in the bay window, I've been told to keep the bay window one as a double radiator to account for heat loss and obviously I'll be looking at ways to retain heat. I can achieve the desired BTU with two radiators but I am worried that the room will end up with a cold spot if i do not replace the third, especially as its nearer the stairs, should i be concerned or should i replace the third radiator but turn the temps down on all of them with TRV's?

Interested to hear thoughts from the experts.

 

[gpbeck]

No point in doing anything with the radiators if the flow to the existing radiators is insufficient. That will determine how much heat is delivered to the room. Measure the temperature of the incoming flow when system is running max and radiator lockshield valves wide open. That is the temperature you would need to use to calculate heat outputs. Standard assumes 70deg but yours might be less than 50deg. This would at least double size of radiators needed, looking at manufacturer specifications for the difference between room temp and mean radiator temp. So consider a re-pipe in at 22mm pipe. You might still need the biggest radiators that would fit.