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Hi all. I am looking for a raditaor for my 4.5 meter by 2.5 meter conservatory and want to make sure I get one that will do the job. I found a Vienna 4 column radiator for sale which is 1400 by 600 and quotes a heat out put of 3600 watts or 12276 BTU. Would this do the job? Also there output seems much higher than comprable products on the market which only quote about 8000 BTU. Could they be pulling the wool over my eyes. I have done a google search and can't find that Radiator anywhere else. any help would be very much appreciated
Thx
bokkie

Whether the radiator output is sufficient for your conservatory is not possible to say as you have neglected to give the construction details.

The heat loss between single glazed glass and triple wall polycarbonate roofing is massive. So is the difference between single and double glazed windows How big are they?

Heat outputs can be confusing too. Obviously the output will vary according to the heating water temperature and the ambient room temperature.

Generally outputs should be calculated at T50 where the mean water temperature is 70deg C and the room temp is 20deg C, but this is not always followed.

Thx for the reply. The conservatory will be 4.5 meters by 2.5 metres with a roof height of about 2.3 meters. It will be full panel double glazed and coated planitherm glass(no dwarf wall) which has a u value of about 1.4, the full 4.5 meter width. The roof will be pilkington k blue glass which has a similar u value and side panels will be the white moulded panels they use. I have been looking at a 4 column rad in b and q with a heat output of about 7000 BTU but am not sure if this will be adequate any help is greatly appreciated as I want to make sure I get the right rad for the room. Better having to much heat than to little.

The conservatory will have Planitherm glass the full 4.5 meter width from floor to ceiling. I believe the u value is 1.4. The ceiling will be Pilkington Blue with a similar u value. The side panels are the regular white moulded plastic Panels. The length will be 2.5 meters and the ceiling about 2.3 meters. I was loonking at a 4 column rad at b and q with a heat output of about 7000 Btu. Do you think this would be sufficient for the purpose or should I get something with a bit more? Thanks for your help

To calculate the heat loss, two calculations are needed.

Ventilation

Volume (m3) x Air change (say 2) x Temp difference (22) x v-factor (.33)
will give loss in watts.

Add to fabric loss

Area (m2) of each wall/window x Temp diff (22) x U val

Add 15% to total.

Don't forget the floor which has a U value of possibly 0.45
Ignore the internal wall as this will probably warm the room.

A quick calc tells me this comes to about 1.5kw or a shade over 5000btu

Frankly, I would use this as a minimum, but it depends on how warm you like the room and which way the conservatory faces. It will make a difference where the rad is placed too. If it is on the inside wall, then the conservatory will feel colder as the heat source should be placed in the coldest part of a room.