This sound okay for split loops?

Lou Miller

I posted a few questions last week about this, but have been wondering about changing things. I'm having my boiler, along with the piping replaced throughout my house. I'm leaving the existing 7" cast iron baseboard (just trying to save some money, will considering replacing and/or altering it down the road). I was reading the heating Q&A section here and came up with the following: I'm going to have three loops. 1 will be a continuous loop with 70' of 3/4" copper fin tube. The other two will be split loops with 1" pipe feeding the loop and a 1" return. I was going to run 1" and reduce it down to 3/4" at the tees. The first of the split loops will have 32' of baseboard (everything is the 7" cast iron here) on one side and 38' on the other side. The second loop will have 38' on one side and 46' on the other side. My concern is that I have roughly 20% more baseboard on one side of each loop. I'm guessing here, but shouldn't these loops be okay given that they aren't very large loops? Or am I going to have issues with them being unbalanced? Is there any reason not to install this type of system with cast iron baseboard (the Q&A section addresses fin tube, but not cast).

Originally I was going to install a one pipe system with monoflos for all of the loops. For aesthetic reasons, we started thinking about the best way to hide the pipes in the basement (basement is finished). So that's where I came up with the idea of just using a simple loop where I use the baseboard as my pipe, but figured it would be best to make them split loops.

Anything wrong with my way of thinking here?

Weezbo

it seems easy ....to do..

and for the most part it would be a better thing to do however , he place you "split" the loops has a great deal to do with the "rightness" of it.splittin say a loop in the middle of a room would likely cause more hassels than you would want.mostly because your designe would be in imbalance in that room...depending on what supplies what sorta is a big deal in that respect....

Joe Brix

Just add some flow control

valves to each split so you can tune the BTU output and bleed the BB easier. Cat iron BB is the best anyway. Better that you keep cast iron on both sections of the loop then having a combination of CI and copper on the same zone.

Lou Miller

No loops would be split in the middle of a room. Each loop is basically going to supply heat to 4 rooms, 2 rooms per split. The house is a rancher and the two split loops will be for the mian level of the house. The third loop that will be copper fin tube is in the basement. I'm going to discuss it with the contractor I have doing the work later on tonight. I just wanted to see what some of you thought about it before I approached him with it. I'm leaving most of the decisions to him, but it can't hurt to educate myself as much as possible. He designed a system for me, but it'll have a negative impact on some things I'm planning to do down the road (which he wasn't aware of when he designed the system).

Lou Miller

Joe,

You mean like a TRV? Or are you talking about something else? Only way for me to make a TRV work would be to add some kind of bypass, right? Since each split is going to control two rooms, whatever flow control I add is going to have an impact further down the line on the split, no?

Joe Brix

True

But I just meant that you should have ball valves on each split. To purge air out easily, you'll need to close off each 1/2 of the split loop or air will keep moving from one side to the other. I'm sure each half does not have the same length or rads, rooms might be bigger or have less insulation, or have a northern exposure, etc. So you might want to restrict flow slightly on one of the halves if you noticed one of the splits getting excessively warmer. Just suggesting a cheap control addition.