Hydronic System: Will This Work?

Phil Gaudio

I currently have a boiler with two heating zones (baseboard heat), and a zone for an Amtrol domestic hot water tank: each zone has its own circulator. I would like to add two additional zones: 1 zone for an addition which will use baseboard heat, and 1 zone for supplying a heat exchanger (the heat exchanger will supply heat to a workshop, and this loop will contain glycol, hence the heat exchanger to isolate the boiler water from the glycol). I currently have 1" main supply and return lines (headers?) coming out of and into the boiler. Each of the zones comes off a T from the main line, with 3/4" lines. I was planning on simply adding the two additional loops by expanding the header (two more T's to two additional 3/4" lines/loops) and adding the necessary circulators (Taco 007) and associated isolation/check valves. I would rather not get into any sort of primary/secondary designs (I'm in over my head already, and I'd like to keep this retrofit as simple as possible). Does this approach sound reasonable? Also, the loop that will feed the heat exchanger on the boiler side will be fairly short (less than 10 liner feet of 3/4" tubing/pipe). Any concerns that the Taco 007 may be oversized for this loop? Thanks

Alan(CaliforniaRadiant)Forbes

Addition

Sounds OK as long as you're not adding more than the boiler can handle.

Check the spec's. on the heat exchanger to make sure the 007 can overcome the pressure drop. I haven't seen too many situations where a 007 is oversized.

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Kal Row

use a grundfos 15-58fc

comes with 3 speeds and a built in check valve

you need to prioritize the hot water to kill the other zones when you need hot water

you need to have a temp sensor locking out the pump on the glycol loop until the heat-ex reaches full temp, cause if 0 degree glycol loops through the heat-ex without a good heat supply on the other side – the fresh water side will freeze and bust forthwith

you need and expansion tank on the glycol side, but don’t leave the makeup water pressure on, since if you spring a leak – the fresh water supply will wash out the glycol and then you will have a bunch of leaks

you might be in way to deep

Dale

Couple of things

I too think this will work as long as you follow the suggestions in the other posts. Also I would put some sort of aquastat on the garage floor so the water temp and or floor temp couldn't get over design. and You are making a pressure vessel on the other side of the heat exchanger so a 30 pound relief might be a good idea. And water testing/flushing is a must for glycol so put in what ever you need to so a yearly test can be done simply. And even though the chance of failure is low if you don't have a backflow protector on the boiler water cold fill inlet already adding one is a good idea.

Dave Castelli

Reverse flow

Have a HWS/HWR mains and need to pipe in boilers with a reverse-return system. Have primary and secondary pumps.Not understanding your explantion in " Understanding primary-secondary pumping thanks