Outdoor Wood Furnace Info
All-Purpose OWF Discussions => General Outdoor Furnace Discussion => Topic started by: atvalaska on October 26, 2014, 11:03:34 AM
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I just fired my boiler for the 1st time ever on Friday moirn the "paperwork" said to set the boiler to 180 @ 18 psi and a 10 deg differential ...... why ?? I set it to 170 and then the 10 ...and the psi hangs at 20,( both the gauge that came with the boiler and my aximon boiler tender), thing is when the boiler shuts down after a call for heat the temp climbs to 175 and stays there... I've had to only add wood 1 time since Friday! 21 to 12 deg outside temps, heating a 4 zone slab in 1200 sqf shop (70degs in here is a bit much !) last call for heat in the shop was Saturday morning at 9am the again last nite at 2am I have two pumps both GF one regular 3 speed after my 4 way valve to run the zones and one the alpha that pumps from the boiler thru the 4way and back .... I put the alpha pump in auto-adap and it burms 43 watts and pumps 11 gpm ...with no call for heat ........... seems mighty high for a pump just pushing a loop with no calls for heat .... how to go about setting the "speeds" and what should I be looking for in return temps (of the water coming back into return ) I have my 4 way set to supply temps between 85 and 110 on a outdoor reset, my return boiler water at 140
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very 1st fire
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;(
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ATV - The alpha is pumping crazy fast, because it is such a short loop. Might want to try one of the other setting on the alpha to see if you can slow down the water a bit and still maintain a delta T less than 20f. Cause if I rememeber you have 1" PEX right, and 11gpm is a bit fast; if you have 1 1/4" -> 11gpm is ok water/pumping-wise.
In regards to your calls for heat, I am not sure of you heat loss; but that seems like a might big boiler for only a 1200 sf slab.
About the temperture of the boiler rising after a call for heat, that is somewhat normal condition called "overshooting".
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I have 1.25 pex ...120' there&back, the building is only calling for heat 1 or 2 times in a 24hr period but every time I go look at the pump in auto a dap ..its running 11 gpm ....is my pump on "the short bus " of its leaning curve? seems to me it should be sleeping 22 hours a day :bash:
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OK, might be a dumb question, but does your Alpha run all the time or just when there is a call for heat?
If you are running 100% of the time and you want to reduce the GPM, you may want to try the constant pressure feature of the pump. They are the three indicating bars to the right of the auto-adapt.
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yes all the time ....is it still learning?.....I put it in auto -a-dap last nite at 7pm ...going to see what that does for it , My 4 way in the shop is set for 85-110 degs on the outdoor reset...I was getting a slug of 120-130 temps at the manifold ,so I moved the sensor things settled down after that and I found that the gf 15/58 3 speed after the valve ,needed to be in the speed 2 spot then the 4way was/could work, well see tonite........I moved my boiler temp to 179 and a diff of 10 ....I seen that moving the diff to much/to low was lowering the psi just enough to have the aximon kick on and bring her up >>>then it would be "to much psi" when she got up to temp
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It should not take more than a few minutes for the auto-adapt to "LEARN", as the pump is looking for a balance between power consumption, gpm and pressure. Somewhere in the circuit board this happens, I guess.
...that being said I have an alpha with a varying load behind it; it can have anywhere from 1-12 loop open, this is where auto-adapt really shines (can go from 1gpm up to about 6gpm, with a swing from 22watts to 42watts). Basically the auto-adapt features, prevents reduces the potential to over or under pump a system.
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Great description LittleJohn! I personally would like to see one with more umpfh, lets say 5-20 gpm
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Great description LittleJohn! I personally would like to see one with more umpfh, lets say 5-20 gpm
I agree with Slim, about being awesome ;D ... and possibly with the bigger SMART pump.
The only concern I would have pushing water over 10gpm, would be velocity issues in the fittings!!! You don't want to go too fast, and create more issues with water turbulance related leaking, than with not enough heat.
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Great description LittleJohn! I personally would like to see one with more umpfh, lets say 5-20 gpm
What pump beyond the Grundfos Alpha possesses the "umph" level (5-20 gpm) you are talking about Slim? Trying to understand why you are supporting a faster flow rate. Thank you for any clarifying information. :thumbup:
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Great description LittleJohn! I personally would like to see one with more umpfh, lets say 5-20 gpm
What pump beyond the Grundfos Alpha possesses the "umph" level (5-20 gpm) you are talking about Slim? Trying to understand why you are supporting a faster flow rate. Thank you for any clarifying information. :thumbup:
He is probably looking for something along the lines of a 26-99, but with the SMART or Auto-adapt feature
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He is probably looking for something along the lines of a 26-99, but with the SMART or Auto-adapt feature
Thank you Littlejohn. I am ignorant of pumps really so I ask this: what is the "advantage" of going with a larger pump then?
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Sloppy its kind of like why do you put a bigger engine in your car ;D, you want to GO FASTER :thumbup:. But in the pump world, "Going Faster" mean either more head pressure or more volume (GPM)
***Just remember, if you overpump (typically water velocities faster than about 5ft/s in a heating system) IT WILL cause damage, start out as excessive noise in the system and eventually erosion of metalic fittings.
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Thank you LittleJohn.... makes sense to me. :thumbup:
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Grundfos Alpha ... I talked to gf....don't use the gfa..as a main boiler pump ....it "shines" on your zone valved system ... my auto adatped did learned that my system/lines are a pumping 9 gal per min it found the flow...! that's good to know! ....but not what I had in mind for the pump ...I was told to swap my gf 3 speed that I have on the zones for the gfa....here I go !!!