Can you mix infloor and antique radiator
| Posted in Energy, Heating & Insulation on
I am remodeling a 100 year old house with a forced hot water heating system that was converted over from steam (I’m told). The existing radiators have seperate supply and return lines and the plaster and lath around the pipes don’t seem to have been disturbed so I have my doubts that it was steam at a previous time.
But I digress….
the only reason I mention this at all is that I want you to know that my system is kind of “frankenstiened.”
My question:
I want to add infloor heat in the kitchen and bathrooms but retain the cast iron radiators in the other rooms. Do both distribution types work well together? Is it necessary to regulate different pressures or anything?
What else should I be thinking about?
Replies
I am definitely not an expert on this at all, but somewhat familiar with it as I installed a bunch of antique radiators and piped them. There are two different ways of plumbing them, one is the homerun system with a manifold using pex, the advantage being that you can zone each radiator. The other way is routing thru each radiator with a monoflo fitting that sends some water to the radiator and the rest on down the line. There shouldn't be any problem mixing styles of radiators, the pressure isn't a factor.
Richard James Tolzman
Mixing radiators I can see no problem, but how about radiators and infloor tubing?
I have heard from a heating contractor that cast iron radiators (and baseboards) require different temps and flow rates than the newer sheet metal fin types. I don't know this for a fact, but it seems to make sense.
I did this once, not with cast iron radiators but with baseboard units. I added the radiant floor heat (did this at the request of the owner) the mixing valve system has been a pain ever since. I would add a second boiler. Like some of the other people who responded, I and not a proffesional.
the above posts all said "I don't know for sure, but..."
you need to talk with hydronic experts, and unless one chimes in here I recommend that you ask your question at http://www.heatinghelp.com.
Yes, you can mix the two using one boiler.
No, the temperature or flow will not be the same, so you will require a distribution manifold and controls to separate the two.
Your steam system was probably a two pipe steam system.
Not rocket science, but definitely not the job to give to an HVAC person who does not specialize in hydronic (forced air is so much more simple and more common that there tends to be a distinction in expertise, is why I say this).
Good luck, and 'happy hydronicing'
oops, 'wetheadwarrior' already did chime in.
Also, the reason why I said what I did about forced air and hydronic experts is that you want to avoid the problem that GCOURTER had. That system was probably not properly ballanced by design. The ballance valves and other adjustments are intended for fine tuning and rely on a good design to start from.
yep yep
you is right!
The July 2002 issue of Fine Homebuilding covers this topic very well. See page 22, Q&A. The question was titled "Baseboad vs. radiator heat". In summary they say you can use both on the same system, but will notice a temp difference. The radiators make your skin feel warm while the baseboards use convection to make the air warm. Although the ambiant temp is the same in both cases, you feel warmer in the room with a radiator. This can be solved by zoning the system.
Good point mat, I've also read that cast iron rads provide radiant as well as convection, whereas baseboard are primarily convection. Richard James Tolzman
Fin Tube baseboard is 10% radiant and 90% convection but the convestion is a lot more gentle than scorched air.
Yes, you can do it. Pressure is not the issue. Temp is. Put them on separate circulators as head loss is different.