Four radiators from one branch?

Chuck_17

Due to a floor plan change I want to connect four radiators to one branch (for convenience of connections instead of tapping the mains which are large at this point near the boiler). This question applies to both steam and condensate.
The branch runouts are below the radiator. The radiators are all close to each other right above the main. The sum of the radiators capacity (about 58SF) is >> than the existing radiator but I think the steam runout may be big enough 9needs to be confirmed). Is size the only factor I need to worry about? What size? Or are there other concerns? What question am I not asking?

Fred

When you say "Branch" do you really mean a branch off of the main or just what is currently a radiator run-out? What size is that branch? Is this a 1 pipe or 2 pipe system? 58sf isn't that much for 4 radiators. They must be very small. Are you sure of the EDR?

KC_Jones

It depend on pipe size and connected load. A pipe can only carry a certain amount of BTU's and return the condensate properly. It sounds like what you would create is a counter flow main extension off of a parallel flow main. Here is the potential problem that I see. You would need at least a 1 1/2" pipe to connect that amount of EDR to your main and have it function correctly. I am going to go out on a limb and say the existing tap off your main isn't that big. I am guessing you are trying to use an existing tap off the main? I also agree with Fred 58 sounds a bit light for 4 radiators. I would approach this scenario from the standpoint of convenience I would approach it from the standpoint of what is correct and proper. And as Fred said is this 1 pipe or 2 pipe? I assumed 1 pipe with my comments.

Chuck_17

The EDR is correct. They are 4 small wall radiators. It is all two pipe.
I just found a photo. The steam is actually a untrapped run out to a riser (I think as it would have to offset above the ceiling to go anywhere). Bigger than I thought.
New question: I want to put two small wall radiators (Runtal) one above the other. Any concern with one steam and one condensate branch up feeding both? (other than size)

KC_Jones

Again it depends on the size of the pipe, essentially what you are proposing if I understand would amount to a branch main off your main. As long as you keep the pipe size big enough and all the pitch correct I don't see why it wouldn't work. Do you have Dan's book? A lot of this is covered in his book as well as the sizing charts for the pipe.

Fizz

It may depend on your system. I assume you have a 2 pipe set-up, but do you know if your traps are traditional or do you have what looks like an elbow on radiator returns. Reason I ask is we have a Richardson system which is a vapor system and had a 1" branch off the main which then reduced to 3/4" to a riser to a radiator on 2nd floor. Now the 1" part had 3 radiators attached, 2 of which were on one run-out with a combined 38sf of edr, and a 3rd radiator on its own run-out with an edr of 22sf. The 3/4" part of run-out went to radiator with 20sf of edr. Total edr was 80sf,now the specs on Richardson System show a 1" line has 60 sf capacity, and sure enough the upstairs radiator would only heat to just past supply valve, raditor had no heat. Solution was to either replace branch with larger pipe or remove some radiation from existing line. JStar an steam expert and frequent contributor to this site came, look at set-up and felt best solution was to disconnect 3rd radiator(22sf edr) from branch and re-attach it to an existing 11/2" branch off main with 50 sf of edr radiator. Result was all radiators now work! As J star said numbers don't lie. With 60 sf of edr attached to 60sf capacity branch it's like magic. The moved radiator is now on a 100sf line which now has combined radiation of 72.

Chuck_17

Hopefully you can see the attached photo.
The strangest thing is the nipple connection between the main and the riser (in the mirror).
This is in a frat house in case you were wondering.

Steamhead

Chuck said:

This is in a frat house in case you were wondering.

No Bluto poster?

ChicagoCooperator

You'll need another mirror to make those corrections correctly. And I think mirrors double output too, don't they?