My drawing doesn't show air eliminators although I do have those planned for the closed side. The Garn-side of the FPHX is open, but I was under the impression that putting the circ down low would guard against cavitation.
Garn hydronic design
- Thread starter Antman
- Start date
-
Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.
We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.
We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
My drawing doesn't show air eliminators although I do have those planned for the closed side. The Garn-side of the FPHX is open, but I was under the impression that putting the circ down low would guard against cavitation.
Even with flooded suction on a circulator you can
have an entrained air problem and water hammer. I really want to see that you talk
to the systems engineer from TACO or B+G who is also a sales rep in your state.
Two hours work+- and they will have this system ready for you to install.
have an entrained air problem and water hammer. I really want to see that you talk
to the systems engineer from TACO or B+G who is also a sales rep in your state.
Two hours work+- and they will have this system ready for you to install.
What about a two pump with zone valve solution?
I'd pump into the Garn, pump mounted low, since it is an open system.
For the distribution a single delta P circulator with two zone valves. Pump away from a single expansion tank and expansion tank
I'd pump into the Garn, pump mounted low, since it is an open system.
For the distribution a single delta P circulator with two zone valves. Pump away from a single expansion tank and expansion tank
Attachments
![[Hearth.com] Garn hydronic design](/talk/data/attachments/191/191077-0d7c5deb07e95d70f1b62f89dbd63ad4.jpg?hash=9lQR03OXPG)
Nevermind, I found a more recent reference for 2f/s
http://www.supplyht.com/articles/98589-four-approaches-to-hydraulic-separation
I
Garn recommends dropping the supply line down and pumping away from the water level of the Garn (which approximates the PONCP). I am curious why you recommend putting on the return? Does it have to do with cooler temps on the boiler pump and do you see it as pumping toward the PONPC?
And, thank you very much for your diagram. Could anyone please comment on whether a delta P pump with zone valves in the Garn Barn in any way simplifies and hopefully eliminates the need for 300 ft underground control lines as opposed to just using delta T circs which seems to necessitate underground control lines?
Garn recommends dropping the supply line down and pumping away from the water level of the Garn (which approximates the PONCP). I am curious why you recommend putting on the return? Does it have to do with cooler temps on the boiler pump and do you see it as pumping toward the PONPC?
And, thank you very much for your diagram. Could anyone please comment on whether a delta P pump with zone valves in the Garn Barn in any way simplifies and hopefully eliminates the need for 300 ft underground control lines as opposed to just using delta T circs which seems to necessitate underground control lines?
maple1
Minister of Fire
'Control lines'?
Are stat wires control lines? Cause I think you would need wires between the thermostats in the house, and the zone valves in the barn?
But if the zone valves & dP pump were in the house, you shouldn't need wiring between the house & barn - I don't think.
Are stat wires control lines? Cause I think you would need wires between the thermostats in the house, and the zone valves in the barn?
But if the zone valves & dP pump were in the house, you shouldn't need wiring between the house & barn - I don't think.
By control lines I mean the wires that will turn on the pumps in the Garn Barn - I guess those would be stat wires underground if I were to put delta T circs to each of the houses in the Garn Barn. I cannot see any way to run lines underground that far, although I do have several extra pex lines if I need.
What I am trying to determine is whether or not putting a single delta P circ in the Garn Barn as suggested by Hot Rod, could that eliminate having to put control lines underground?
So, if I have a dP circ like the Taco Viridian VR 3452 in the Garn Barn, could I put a zone valve in each house (each 300' away from the Garn Barn) such that when there is a call for heat in one of the houses, its zone valve opens and the VR 3452 ramps up by sensing the change in pressure due to that zone valve opening?
If so, could I then put a flow switch in the Garn Barn which would trigger the boiler circ (0010 setpoint circulator) and this would eliminate the need for any 300' underground triggering wire?
I am open to any other suggestions. Thank you
Attachments
![[Hearth.com] Garn hydronic design](/talk/data/attachments/194/194703-678d148297f528698745b52efa38477a.jpg?hash=mxu_PrTd2e)
The specific feedback I am looking for is:
1. What kind of cable should I put in my 300' underground runs to start the primary circ in the Garn Barn?
2. Could that same cable also start the boiler circ or would it be better to have a flow switch triggered by the primary circ start the boiler circ?
1. What kind of cable should I put in my 300' underground runs to start the primary circ in the Garn Barn?
2. Could that same cable also start the boiler circ or would it be better to have a flow switch triggered by the primary circ start the boiler circ?
Also, can anyone suggest what kind of wire to run 300' underground to be used for 24v controls, please?
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
I would just use water and check your strainers more often if you are worried about cleaning your piping.
============================================================================
16 gauge stranded wire but I would not do anything until you compensate for line drop of at least 10% so you may not be able to manage the needed 24 volts AC.
Your going to have to talk to an electrical wire supplier to be sure as the line drop power loss is the major issue.
Edited to correct my mistake.
Last edited:
I have contacted a couple of HVAC friends and electrician, and, to clarify, the controls are 24V AC
surefire
Member
Antman, thanks for this thread. It's been informative and watching your planning and attention to detail has been an inspiration. It's exciting to see your project progressing; please keep the photos coming!
We are about to finish the distribution system but could someone please answer this - can I use a single FPHX to keep both tanks shown here in series hot? I was planning to insert a 20 plate FPHX between the blue valve at the cold water inlet and the first hot water tank but I wasn’t sure if it would heat both tanks or not?
Attachments
![[Hearth.com] Garn hydronic design](/talk/data/attachments/215/215861-e249f3acb52c8bd14b72691ee9ddc1fa.jpg?hash=LB9fI65H8m)
Buzz Saw
Minister of Fire
Are you going to run a circulation pump to loop the water through the FPHX multiple times to bring the water up to temp? A single pass through a 20 plate won't be enough to warm the water to 125*(so I've been told).
Sent from my SM-G950U using Tapatalk
Yes I plan to have a circ on the boiler side so that when cold well water replaces the hot water being used at the fixtures, that cold water goes through the FPHX and get heated by the boiler water which will probably somewhere between 150-180F since I have 3 fan coils, a pool and spa tube and shell hx, and a towel warmer, which I think are all high-temp emitters.
surefire
Member
I'm a sparky not a plumber but with the dhwt hooked in series like that one tank is doing all the work heating the cold water and the other is just acting as a holding tank and coming on to maintaining the temperature if it drops from standby losses. If you want quicker recovery they should be plumbed in parallel. As for the fphx it would be heating the water as it enters the first tank but without a circulator on the dhw it wont be maintaining that temperature in either tank. Is 20 plates enough, I don't know, you may be able to mess around with an online calculator to find out.
I have 3 Taco HAFC201 fancoil controls wired between the thermostats and air handlers. They work great but I need help determining how best to complete my dual fuel needs. I want to switch back to propane (hopefully automatically) if the Garn tank temp falls below the usable temperature range. The HAFC201 has contacts for an aquastat on the return line of the fancoil but I am unsure:
1. if the air handlers would automatically switch to propane when temps falls below the aquastat setting
2. which aquastat would work best for this scenario
3. if there is an alternative to using aquastats
Along the same lines, which aquastat or temp probe would be best for the freeze protection contacts which are adjacent to the watercoil contacts?
1. if the air handlers would automatically switch to propane when temps falls below the aquastat setting
2. which aquastat would work best for this scenario
3. if there is an alternative to using aquastats
Along the same lines, which aquastat or temp probe would be best for the freeze protection contacts which are adjacent to the watercoil contacts?
The honeywell 8124L1011 triple aquastat relay with conductive paste is the best triple aquastat to use for this to oversee the low limit and high limit temperatures for the propain fired boiler making it completely independent.
To clarify, the boiler is wood fired, and the air handlers were propane, and now the thermostats don’t go directly to the air handler. They go to the HAFC201 then to the central heating and AC air handler
The way I wired mine was by getting an external aquastat that clamped onto the pipe where the water entered the heat exchanger. It was open if temps were above the set point and closed if they were below. On the wiring coming from the thermostat there should be seperate wires to turn on the air handler and the furnace. This aquastat was spliced into the furnace wire so that when the heat was commanded by the thermostat the furnace never recieved the message as long as the water temp was above the set point. It worked great.
Similar threads
