Fan/natural convector heating circuit temperature

[slaw]

Dear All,
I'm new in this country and I heard from my collegue that when you use fan convector/ natural convector or trench heating, the heating circuit shall be constant temperature? Is that true? Where I can read more about this specific situation.
If it is not true, is there anything that do not recomend use of fan convectors, convectors with traditional panel ratiator in one weather compensated heating circuit? ( that they need separate weather compensated circuit because of different thermal characteristic?)
Thanks in advance.

 

[Moss5]

http://www.myson.co.uk/slimline.htm
This link gives info on fan convectors.
They have high output for small size.
Fan noise can be an issue.
More parts to go wrong than a panel radiator.
Ideal where space is at a premium.