Radiant heat zone off of Steam boiler

Pete_18

I was reading Dan's article at:
http://www.oldhousejournal.com/magazine/2003/february/hybrid_hydronics.shtml
where he talks a little at the end about adding a radiant heat zone off of a Steam boiler.

Just like adding a normal HW radiator zone, is it safe to assume that you can use 1/3 of the supported EDR load for a radiant zone? How does this affect the existing load on the boiler from an efficiency or sizing perspective (or does it not? I didn't know if the steam production ability is impacted when this much water is diverted to and from it?)

What kind of load (if any) or efficiency impact to the existing steam zone would you expect.

When doing the radiant-zone off of a steam zone, do you have the same limitations that are mentioned in the article for a Hot-water system where a contractor would be required to use a 3-way mixing valve so that the temperature could be lowered to 120F? This may sound like a silly question, but if the 3-way mixing valve is constantly adding water to lower the temperature, where does the excess water go and would this constantly waste water to lower the temperature?

Can radiant off of a steam system be run as a separate zone or is it required to be a slave to the existing steam zone? (I was a little confused on this part since the section of the article that talked about this was specific to HW)

If you need to exceed more than 1/3 EDR of the steam boiler rating, would you need a completely separate boiler to handle the radiant zone or is there some other way to efficiently leverage some of the existing heat production?

Bob W._3

Does he expound on some of those issues in this?:

http://www.heatinghelp.com/heating_howcome6.cfm

Jim_77

radiant/steam

some more info on what to expect and where you get the radiant loop schematics from my peerless steam boiler in my 1860 home would like to use plastic staple up to warm floors and is it zoned secondary. its like a barn in here.