Trying to add a radiator to existing zone

Reply

  #1  
Old 08-12-13, 06:42 PM
Member
Thread Starter
Join Date: Mar 2008
Location: NJ
Posts: 113
Received 0 Votes on 0 Posts
Trying to add a radiator to existing zone

OK I have a boiler with hot water cast iron radiators. One radiator is on its own zone (#1) the rest are on another zone (#2). I would like to add one of my radiators from zone #2 to Zone #1. The zone #1 radiator is fed off the loop and then was piped back to boiler with its own return using 1/2 copper pipe. Is there anyway I could use that 1/2 copper return for two radiators?? That would make it so much easier for me. Pictures will show zone valve and return line for the zone #1 connected back at boiler.Name:  DSCN2325.jpg
Views: 3652
Size:  39.6 KB
 
Attached Images  
Sponsored Links
  #2  
Old 08-13-13, 04:12 AM
Member
Join Date: Jan 2012
Location: Canada
Posts: 2,739
Received 15 Votes on 15 Posts
I am surprised it's 1/2" copper. Most systems I've seen where 3/4" and up. The issue with 1/2" is that there is not a lot of water volume (and heat). I would imagine the return is a fair bit cooler then the feed to the rad.
What size of pipe is the actual connection on the rad? Is there a reducer between the feed line and rad?

As for your original question, the answer is yes you can run the second rad on the return feed (series connection), BUT...
The water feeding the second rad will be a fair bit cooler (see note above), which will greatly reduce the potenial efficency of the second rad.
If possible (and reducers currently being used), I'd suggest upping the size of the copper pipe from 1/2" to minimum 3/4".

Slightly off topic...
The wiring of your valves should really be cleaned up. I see a few issues that concern me with how the wiring is exposed.
 
  #3  
Old 08-13-13, 08:03 AM
Member
Thread Starter
Join Date: Mar 2008
Location: NJ
Posts: 113
Received 0 Votes on 0 Posts
Drawing of Radiator layout

Thanks Mike. I will attach a quick drawing. Maybe it will help seeing everything. Hopefully you can read it. Drawing and plumbing are not my strong points. Also this is a Ranch home. Boiler in basement all radiators on first floor. My game plan is to move the feed pipe located by my basement stairs to give more headroom. Since I plan on doing that I might as well fix a few other things. Like adding the radiator #2 to Zone #1. Zone #1 is in a cold room and if I do not have a fire in the wood burner the heat is always on and is hard to satisfy the tstat at times. On really cold days I would have to turn up Zone #2. The radiator in Zone #1 always gets real hot even though the ˝ in return. This was a change made by someone else. I can see it use to be hooked the same as the rest of the radiators. I think it is an 1 inch feed and all radiators have ˝ pipe connecting to feed/return. So my plan is to:
Add rad 2 to zone #1
Remove Radiator #3 it is not needed
Extend feed pipe by stairs and make it closer to exterior wall of house (closer to rad 3 in drawing)
And YES tidy up those wires
Any suggestions would be greatly appreciated. I would love to use the ˝ return and keep the plumbing to a minimum.
Also what should I know about this fitting in the picture.
Name:  DSCN2256.jpg
Views: 3093
Size:  28.4 KB
 
Attached Images  
  #4  
Old 08-13-13, 10:17 AM
Member
Join Date: Jan 2012
Location: Canada
Posts: 2,739
Received 15 Votes on 15 Posts
Not to stray too far off topic, but have you looked into why that room is so cold? Is there an insulation issue?
It kind of seams odd that being a single floor home, one room would have it's own zone and be so cold.

I noticed that in your drawing, there are no pumps shown. Is there a circulation pump in your system?
 
  #5  
Old 08-13-13, 11:31 AM
lawrosa's Avatar
Super Moderator
Join Date: Dec 2010
Location: Galivants Ferry SC USA
Posts: 17,799
Received 10 Votes on 8 Posts
I would open zone 1 zone valve manually and leave it open. Turn that t stat all the way down as not to use it... This will make it all one zone and work off the zone two t stat...

If you do not wants rad # 3 just shut the valve to that rad and you will get no heat from it...

As far as the cold room...Insulate.....

That device in the picture is a mono flo tee.... Pushes water through the radiator with a venturi effect...

All above requires no plumbing skills...


Butif your not going to insulate and you dont need rad #3... Take rad #3 and add to the cold room.... But I would still keep all on zone....
 
  #6  
Old 08-13-13, 02:23 PM
Member
Thread Starter
Join Date: Mar 2008
Location: NJ
Posts: 113
Received 0 Votes on 0 Posts
How about this

Thanks for all the suggestions. Let me add some info. I would love to insulate but I have to be realistic in that it’s not going to happen. The cold room is my living room. Way before I moved here it must have been a covered breeze way to the garage. So this room has no attic, no crawl space, it has a front door, windows and a sliding back door. I can tell the radiator use to be on the other side of the wall in the kitchen. So they snuck the radiator into the living room in the only spot they could and made it a single zone. Adding another radiator I would have to rip up the floor, so that not happening either. Also I am sure that is why there is a wood burning stove in the room.

Like I said there are too many other things on the list to do so I have to move on and give up on insulating. With the wood burner I like having two zones the second zone will be just bedrooms and bathroom were the heat from wood burner does not travel. The rest of the house does heat well.

The reason for doing this is to move that feeder pipe further from basement stairs. Also the third radiator has been shut off for a few years now and is just taking up valuable space. So I would like to get it out.

Does this look OK. Even though it might not be the best way. I was thinking of adding a new zone valve for zone #2. I have to cut that pipe anyway in order to splice in 18 inches or so to move feeder away from stairway. I was thinking of just having the tstat for zone #1 operate both of the existing zone valves (if possible). Then tie return from rad 2 to rad 1 with ˝ copper.

Do I have to worry about where that Mono flow tee is on rad 2 if I do this? Should it be on return or supply side?? Not home not sure where it is. I most likely will have some drain and refill questions later on. Thanks Again for the input!!!! Sorry for bad drawings in red would be new.
Name:  DSCN2350.jpg
Views: 4322
Size:  18.0 KB
 
  #7  
Old 08-14-13, 06:58 AM
Member
Thread Starter
Join Date: Mar 2008
Location: NJ
Posts: 113
Received 0 Votes on 0 Posts
I should have stated that the feed is coming off the top of boiler in drawing and circulator is on return side of the boiler.
 
  #8  
Old 08-14-13, 10:41 AM
Member
Join Date: Nov 2011
Location: USA
Posts: 406
Received 1 Vote on 1 Post
Like lawrosa mentioned, it looks like you have a "one-pipe, diverter tee" (also called "mono flo" or "venturi") type of piping. In such case, adding another heat emitter is not as simple as cutting into the existing system and adding new zone valves. There are some physics involved (pressure differentials, etc.). You might want to bone up a little more on diverter-tee systems before you proceed.

See for example: Heating Help - Diverter Tee Hot Water Heating FAQ
 
  #9  
Old 08-14-13, 04:53 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 1 Vote on 1 Post
Mike, one thing I'm seeing (and I confess I only looked at your last post with drawing...) is that in order for zone 2 to get any heat, zone 1 will need to be open. Am I misunderstanding something?
 
  #10  
Old 08-14-13, 05:04 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 1 Vote on 1 Post
When a rad is removed from a diverter tee system the pipes should not simply be capped. One of two things should be done:

1. Connect the old radiator lines together.

2. Remove the diverter tee altogether and replace with pipe.

Reason is that an unused diverter tee will add head to the system.

Regarding pipe size: 1/2" pipe is good for about 15K BTU. If the two rads together are less than 15K BTU, you should be OK with that. You will need to measure up the rads to determine their output. There are charts on the internet to help with that.
 
  #11  
Old 08-14-13, 06:10 PM
Member
Thread Starter
Join Date: Mar 2008
Location: NJ
Posts: 113
Received 0 Votes on 0 Posts
Thanks Guys

Thanks Rockledge! Looks like some good info there. I will have to try to absorb it some more. Not sure how to term my system. But wouldn’t it be kind a like a one-pipe/two-pipe system????? It has already been modified. I will attach a better pic of my existing system and what I am thinking of doing. I understand what your saying about the physics. Nothing ever is easy. I guess that’s why I would like to run it by here. I not sure I would be able to figure out if this will work or not????

Anybody think I could pipe it any of these 2 ways?? In the second picture I would wire both zone switches to work off of same thermostat(zone 1). Zone #2 has a separate tstat.

Thanks NJ. No you are not missing anything except that I zoned out on that one.

I had no Idea about that when removing a Rad Thanks Again!!

OK I will search for a chart to see if I can do it
Name:  DSCN2376.jpg
Views: 2910
Size:  14.2 KBName:  DSCN2377.jpg
Views: 4146
Size:  14.8 KB
 
Attached Images  

Last edited by mikeevan; 08-14-13 at 06:46 PM.
  #12  
Old 08-14-13, 08:28 PM
Member
Join Date: Nov 2011
Location: USA
Posts: 406
Received 1 Vote on 1 Post
Not sure how to term my system. But wouldn’t it be kind a like a one-pipe/two-pipe system????? It has already been modified.
I'm wondering if the Rad 1 branch piping was changed to its current configuration in order to achieve a greater difference in pressure between the tees, for the purpose of getting more heat out of Rad 1, by increasing the flow through the branch.

Or it could be that someone tried to add a zone valve to the Rad 1 branch, but that caused flow problems in the original design (due to increased resistance in the branch supply), so the return piping from Rad 1 was then modified to address that issue.

Just thinking out loud here....
 
  #13  
Old 08-15-13, 09:19 AM
Member
Thread Starter
Join Date: Mar 2008
Location: NJ
Posts: 113
Received 0 Votes on 0 Posts
It was done due to an addition that needed its own zone. The difference in the heat load needed between these 2 zones are big enough to justify it.
 
  #14  
Old 08-15-13, 03:05 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 1 Vote on 1 Post
No you are not missing anything except that I zoned out on that one.
Pun intended?

Back up to the removing radiator for just a bit more of the 'why' they need to be connected, or the diverter tee removed altogether.



This graphic shows a typical diverter tee setup.

The way these tees work is by placing an 'obstruction' (the 'venturi') in the path of the flow. This obstruction is what causes the pressure difference and causes part of the main flow to 'detour' through the radiator.

If the radiator is removed and the pipes capped, the portion of the flow that would normally flow through the rad and then re-combine with the main flow is stopped.

By connecting the two pipes together instead of capping them, the obstruction is mostly removed because you are maintaining the flow that was there originally.

Really though, it is better to remove the diverter tees. If there is only ONE diverter tee, and one 'normal' tee, the normal one can be left in place and it's side pipe capped, but the diverter tee removed.
 
  #15  
Old 08-15-13, 03:21 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 1 Vote on 1 Post
wouldn’t it be kind a like a one-pipe/two-pipe system?
It's sort of a 'hybrid'. There really isn't a name you can put on it.

Originally, before the piping was changed, it would be called a 'mono-flo' or 'diverter tee' system, which implies 'one pipe'.

The new zone isn't really a 'two pipe' system though, it's just a zone piped from supply to return.

A 'two pipe' system would have a supply and return in parallel around the home with a pipe from each going up to each radiator. Ideally, these parallel pipes would be set up as a 'reverse return' system, where the supply feeds into one end of the parallel pair supply pipe, and the return comes out of the OTHER end of the parallel pair. This helps to equalize the flow through each radiator branch because the water is essentially traveling the same distance from the boiler, through each radiator, and then back to the boiler. This eliminates the tendency for the first few rads in the system to 'hog' the flow and starve the rads on the end of the line.

This is a pretty good illustration to describe two pipe reverse return, courtesy heatinghelp.com:



If you trace the path through each rad you will see that it is nearly the same for all rads.
(part of the return line to the rad at the bottom left got cut off, just imagine it's still connected and not leaking all over the place!)

The alternate to this is 'direct return':



Note that the path through each radiator and back becomes progressively longer the further the rad is from the boiler.

But, this has nothing to do with your system, just information overload!
 
  #16  
Old 08-15-13, 03:33 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 1 Vote on 1 Post
Anybody think I could pipe it any of these 2 ways?
Sure...

A drawback to either approach is somewhat similar to that of a two pipe direct return system. When zone 1 and zone 2 are both open at the same time, some of the pressure differential across zone 2 will be lost to zone 1 and the flow through zone 2 will decrease somewhat. How much it decreases will depend mostly on the installed pump's curve.

By piping the two rads in parallel, you would be robbing a bit more from the rest of the system.

I doubt that this pressure change would amount to a problem though. If the new zone had been piped in 1", it might... but it wasn't...

I would be inclined to go with the series arrangement myself. PROVIDING, as I mentioned earlier, that the BTU output of the two rads combined did not exceed 15K BTU.

Have you been able to determine roughly the BTU output of the two rads?

The less zone valves, the better!
 
  #17  
Old 08-16-13, 05:06 PM
Member
Thread Starter
Join Date: Mar 2008
Location: NJ
Posts: 113
Received 0 Votes on 0 Posts
So Far maybe not so good??

NJ Thanks a bundle and greatly appreciated

Pun intended?
Yes

If there is only ONE diverter tee, and one 'normal' tee, the normal one can be left in place and it's side pipe capped, but the diverter tee removed
I have this and will do this

Have you been able to determine roughly the BTU output of the two rads?
I only did it so far with one online calculator but I came a little high 17,820 BTU.

My Rad 1 is about 46 in wide, 25 in tall (2in leg). Has 4 column 26 fins. Victorian 660 style.
Rad 2 is 49 in wide 25 in tall. 4 column 28 fins. Same style

I used this website.
Victorian Carron Cast Iron Radiators | Classic Radiators | Designer Radiators | Feature Radiators

Just some observations on my system.
Zone 1- rad 1 gets pretty darn hot.
Zone 2 usually satisfies tstat without difficulty.
Rad 2 is far from zone 2 thermostat and is closer to Zone 1 tstat and rad 1.
Rad 2 probably does not help satisfy tstat of zone 2.

So I am wondering if I still did a series connection could it still work?
I think Rad 1 would still get as hot and rad 2 hopefully would still get very warm. I actually would prefer Rad1 hotter than rad 2 now that I think about it. But really not sure if it would work?? Any Suggestions

Would I have to worry about return water temp getting to low??? or anything else????

Or does parallel feed look better?? or anything else??

I will have to double check those BTU of Rads.
 
  #18  
Old 08-17-13, 11:48 AM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 1 Vote on 1 Post
I came a little high 17,820 BTU.
If that's for both of them combined, you should be fine.

Would I have to worry about return water temp getting to low?
I doubt it...

Take a look at this PDF also, make sure you understand the difference between "Tube Type" and "Column Type" rads, as the outputs are VASTLY different!

http://www.columbiaheatingsupply.com...ty%20Guide.pdf
 

Last edited by NJT; 08-17-13 at 12:06 PM.
  #19  
Old 08-17-13, 01:59 PM
Member
Thread Starter
Join Date: Mar 2008
Location: NJ
Posts: 113
Received 0 Votes on 0 Posts
Yes 17k that was for both.

Found similar #s in a few searches.

I think I got it right mine look like thisName:  rad.jpg
Views: 2678
Size:  20.0 KB

Oh yeah Taco circulator. I think 007 f5 (black one)

I still have to go over your link better.

Then just have to wait for wife to move her clothes from a closet where pipes are located.

Thanks
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes
 
Ask a Question
Question Title:
Description:
Your question will be posted in: