Closely spaced tees-can I do this?

Richard Chawes_2

Thanks jPaul but the system is already open loop. Mr PDQ, let me try again. Imagine three zones that are pumped. Can I join all of the supplies togther and feed them from one common tee on a primary loop and then return all three zones to a closely spaced tee. The system is on two different floors, the zone circs are in a small box and it is next to impossible to seperate them into three pairs of closely spaced tees. The water heater is upstairs where there is plenty of room to construct a primary loop, place a 009 and a Rinnai. All the supplies and returns are common at this point. Just gang them togther. Would there be adverse pump interactions or would the pumps "see" no difference than as they are now, going into a big dumb water heater.

Richard Chawes_2

Has any one ever joined several zone pump circuits to a primary loop with only one pair of closely spaced tees that are common to all the zones. I have a remodel replacing a tank type water heater running potable radiant floor with a demand (Rinnai). The Rinnai needs its own pump, thus a primary loop. It is imposible to break down each zone so why not combine them all to a common set of tees. Any ideas?

John Ketterman

I don't understand the question. A tee has three "arms" so you can only connect two loops to a pair of closely-spaced tees (of course the third "arm" of each tee is connected to the other tee).

To connect more loops, you need more tees.

In other words, you need to make or buy a manifold. This is quite commonly done.

jp_2

ideas, yes

totally separate radiant floor from the showerhead!!!!!

do not combine radiant with DHW.

Richard Chawes_2

Thanks jPaul but the system is already open loop. Mr PDQ, let me try again. Imagine three zones that are pumped. Can I join all of the supplies togther and feed them from one common tee on a primary loop and then return all three zones to a closely spaced tee. The system is on two different floors, the zone circs are in a small box and it is next to impossible to seperate them into three pairs of closely spaced tees. The water heater is upstairs where there is plenty of room to construct a primary loop, place a 009 and a Rinnai. All the supplies and returns are common at this point. Just gang them togther. Would there be adverse pump interactions or would the pumps "see" no difference than as they are now, going into a big dumb water heater.

kevin coppinger_4

it may be an...

open loop but you are replaceing the water heater now...why not do it right.by doing it right it makes you question moot....kpc

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Plumb Bob

The point of closely spaced tees is there there is no head loss between them. If I understand correctly, you have three circulators in one place and the boiler in another. Well, if you can't separate the circulators, then the closely spaced tees will have to be near the circulators, not near the boiler.

If you have a long run of pipe into which 1, 2, 3 or 4 circulators may be pumping water (depending on whether a zone is calling, boiler is running, etc) then each loop affects the other loop. Flow through any loop depends on whether the other loops are on or off. But in a closely-spaced tee, there is only a short length of "common section", and that is OK.

Again, if more than one circulator is pumping water through the same section of pipe, that section should be as small as humanly possible. You can't eliminate this common section, just make it small.