Hello all-
in another thread, Kabbott raised the fascinating idea of putting a plate HX directly in the primary loop of a primary/secondary system (the HX will be my interface between the unpressurized storage tank and the boiler and heat loads) rather than having the HX “hanging off” a secondary; his approach, as he noted, would allow deletion of one circulator.
https://www.hearth.com/talk/threads/21028/
On the un-pressurized side of the HX, between the HX and the thermal storage tank, I am planning to use "back to back" circulators in opposite directions as has been pioneered by folks here and is being deployed by WoodNotOil.
One factor that putting the HX in the primary may introduce is that my unpressurized loop between the HX and storage may be much more likely to siphon itself out, and/ or leave air in the circulators on the unpressurized side of things, which I know will spell trouble, fast, for wet-rotor circs.
I know that the old-type circulators had separate motors, without wet rotors, but they were huge and electrically inefficient
anyone know whether there are any current-technology, electrically-efficient, not too huge circulators that can prime themselves and that do not require being internally immersed in fluid 100% of the time?
or, for that matter, I welcome any other suggestions on how it might be possible to avoid the unpressurized side siphoning dry and pulling air into the circulators
I thought of zone valves, but from all I've read here and elsewhere, they apparently usually have small inside ports and introduce a lot of flow resistance, which I would like to avoid
thanks
Trevor
in another thread, Kabbott raised the fascinating idea of putting a plate HX directly in the primary loop of a primary/secondary system (the HX will be my interface between the unpressurized storage tank and the boiler and heat loads) rather than having the HX “hanging off” a secondary; his approach, as he noted, would allow deletion of one circulator.
https://www.hearth.com/talk/threads/21028/
On the un-pressurized side of the HX, between the HX and the thermal storage tank, I am planning to use "back to back" circulators in opposite directions as has been pioneered by folks here and is being deployed by WoodNotOil.
One factor that putting the HX in the primary may introduce is that my unpressurized loop between the HX and storage may be much more likely to siphon itself out, and/ or leave air in the circulators on the unpressurized side of things, which I know will spell trouble, fast, for wet-rotor circs.
I know that the old-type circulators had separate motors, without wet rotors, but they were huge and electrically inefficient
anyone know whether there are any current-technology, electrically-efficient, not too huge circulators that can prime themselves and that do not require being internally immersed in fluid 100% of the time?
or, for that matter, I welcome any other suggestions on how it might be possible to avoid the unpressurized side siphoning dry and pulling air into the circulators
I thought of zone valves, but from all I've read here and elsewhere, they apparently usually have small inside ports and introduce a lot of flow resistance, which I would like to avoid
thanks
Trevor
