Take out slantfin fintube - put in c.i. baseboard and radiators?

JeffGuy

Most of my house has 100 year old cast iron radiators, but a rehab in the 1980's put a new family room addition onto the house and removed a couple radiators from the adjoining kitchen and bath. This zone is now all heated with about 50 feet of fintube baseboard. I would like to put cast iron baseboard and radiators back into this zone. The zone is piped completely separate from the rest of the house with a separate circulator, and the zone is currently all fintube, but I plan to take out all of the fintube and replace it with cast iron Baseray baseboard and radiators. A couple questions:

1. Can I assume it is OK to use a single long pipe run for the combination of Baseray and radiators? I know the emitters closest to the boiler will get hotter sooner, but am thinking it worked with the fintube so should probably continue to work (especially since except for the bathroom, the rooms in this zone are open to each other without doors so heat circulates easily). I will pay attention to the EDR of the different rooms in the zone and keep it the same.

2. Can I assume that I need vents on the radiators only, and not on the long run of Baseray (I have a separate purge valve for this zone in the basement)?

Paul48

?

Still got the original mains in the basement that have been plugged? Do heat losses for the rooms and match them with the correct radiators.

JeffGuy

new pipe

Thanks, but I don't want to try to connect to the old pipe for a couple of reasons. Mainly that they added a very large family room, so the existing steel pipe which was mostly removed may not be the correct size anyway, plus I have no idea how to balance the new with pipe sizes, etc.

On the other hand, I have a zone (with dedicated circulator) for the fintube all ready to go, and those pipes run exactly where I need them to go. So it would be easy for my plumber to swap out the fintube with the new baseboard and radiators.

I've done the EDR calculation already and will match that - but I want to make sure its OK to run a continuous loop (like the fintube) and that the venting will be correct.

nugs

CI Radiators

I pulled all the copper fin tube from my own house 10 years ago and put in big cast iron radiators that I took out of a commercial building,  they are 8 tube radiators that are low and long.  Each radiator has 2, 5/8" pex lines run to it and then back to a manifold at the boiler so that each radiator can be precisely adjusted with ball valves at the manifolds.  There are 4 zones on the house so a total of 8 manifolds,  Each manifold has it's own circulator and I am using wilo VFD pumps on them.  The system is all hooked to a Buderus BE using Taco's PC700 for modulation instead of the Logamatic which is way more money than it's worth IMO. 

furnacefigher15

Btu output

If the btu output is the same or close to the rated output of what you plan to replace it with, then the performance should be the same.



Through one 3/4 inch run, you can comfortably connect 40,000 btu of radiation (180 supply) with a 20 degree design drop. Without having a overly noticeable drop in radiator temperature from one place to the next.



Be careful with radiators though, as a small radiator can have a huge output.