It is fine to put low level radiators under a window, and that location is actually one of the most popular places to fit them in terms of space and performance.
Given that the area beneath the window won’t offer much room for décor or furniture, it makes sense to make use of the room with a radiator installation to free up space elsewhere. Also, positioning a low level horizontal radiator underneath the window can ensure the room is heated more efficiently and effectively.
To find out more, take a look at our dedicated blog, The top 10 low level radiators.