can you mix fin with cast iron radiators?

Betsy_2

I have old fashioned cast iron radiators in the original part of my two story house.
I have Burhnam BaseRays in a loop to one addition.
I have BaseRays that are leaking in another room addition (greatroom/kitchen familyroom combo.)
This is in a separate loop from the other BaseRays. I think these rooms are "separate loops," if I understand what a loop is.
Hot water from the boiler to these two additions goes through the older pipes and then branches off to the newer rooms, at opposite ends of the older part of the house. The cold water eventually joins other cold water pipes to return to the furnace. Do I really have three loops?

To solve my leak problem, one contractor suggests used old fashioned radiators to replace the BaseRays that are leaking. (One BaseRay is 19 feet long)

Another contractor suggests installing fin type baseboards as the replacement. The rooms with the BaseRays are 10 degrees colder than the older part of the house, by the way.

I am an unknowledgeable consumer, but I recall reading somewhere that you should not mix rads with fins.

Other info, I am getting a new Bryant BW2 145,000 btu boiler installed in this job.
I would imagine "zoned" heating would be really expensive.
I plan to sell in a year, so don't want to spend a fortune here.

Firedragon_4

I have four types of radiation

in my own home, you can only do it if's zoned by type. I don't know why those Base-rads are not working, good stuff!