Outdoor Wood Furnace Info
All-Purpose OWF Discussions => General Outdoor Furnace Discussion => Topic started by: AirForcePOL on October 15, 2014, 03:18:54 PM
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I've had my 5000e up and running for 15 days now. Everything is going great so far. I recently purchased a wireless meat thermometer and due to nast weather outside I decided that I would just go into my basement and attach it as apposed to hooking it up outside at the stove. I taped it to my water to air HX connections (supply and return). I let it sit for a few minutes, got the reading from the thermometer and then went and checked my stove temp. They were within 1-2 degrees which tells me that I am getting a fairly accurate reading from the thermometer.
Anyway, the other night I was doing the dishes and I happened to look at my thermometer unit that I have sitting on my counter. The air HX is hooked up after the plate exchanger and the supply line on the HX was reading 140's. My stove is set on 185 with a 14 deg differential.
I have about a 125 ft run with 1" pex, 20 plate HX to my air HX and then back to the stove. I have a Grundfos 15-58 running on HI. From what I hear, return temps of more than a 20 degree difference is hard on a stove. Do I need a bigger pump or maybe a mixing valve at the stove? Thanks!
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I was recommended to use a 26-99 and I have 150 ft return trip to the furnace and only running through a 50 plate. Haven't got it up and running yet so I can't tell you what speed I'll be running at yet
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That is a lot of distance for a 15-58, are your pipes nominal sizing or inside diameter?
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How much vertical elevation change do you have? The 15-58 does seen to have a low gpm rating. The 26-96 gives you 26gpm with 30' of head loss and costs almost $300. I'm running Badger 25-10 pumps that give me 34 gpm at 30' of loss for only $110. 2 year warranty.
For $110 it would be with a try. I'm sure you could sell that grundfos if the badger out the bigger grundfos works out. Your dealer may even buy it back.
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It's just standard 1" pex. I used rehau insulated pex. My line goes into the house then drops down about 6 ft then back up 6 ft and back to the boiler. Are most pumps the same length? As in, if I used a badger pump, would I need to add or remove pipe at my stove to make it work? $300 seems like a lot for a pump to me. I think I paid $72 for the 15-58. I have another one that I am going to use for the garage. I could keep the other one as a back up.
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It's just standard 1" pex. I used rehau insulated pex. My line goes into the house then drops down about 6 ft then back up 6 ft and back to the boiler. Are most pumps the same length? As in, if I used a badger pump, would I need to add or remove pipe at my stove to make it work? $300 seems like a lot for a pump to me. I think I paid $72 for the 15-58. I have another one that I am going to use for the garage. I could keep the other one as a back up.
On my short runs in the shop I went with $80 dollar pumps but 1 1/4" line, with 1" line I'd be looking at around lets say a $300 pump. I did buy two Grundfos 26-99FC's though, one for the shop boiler to the FPHX and one from the wood boiler to the FPHX. Around $240 bucks a piece at Supplyhouse.
Seems to be a big jump from a mid head 5-8 GPM pump and a higher head, high GPM pump.
Thats what it sounds like though if your delta T is that high, need more GPM if you want to keep it around the 20-25 degree range.
I think for the most part pumps will interchange with one another until you start to get into the ones that look like a pump attached to a separate motor.
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Try bring up the differential up even though it is 14 degrees check the boiler temp after it fires at 171 and see how much lower it goes before it starts climbing up in temp just something else to check
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My understanding is that the Badger pumps are just the generic version of the Grundfos. They may even come out of the same factory. So, I'd say they are very similar in dimensions. I will add that I had one of my 2 Badgers go out last winter after only a few months of usage. They sent me a new one right away and it was relatively painless. I'm going to order a backup pump to keep on the shelf. I can buy a new Badger 3 times before equaling the cost of an equivalent Grundfos.
http://www.badgerinsulatedpipe.com/Circulating-Pumps_c14.htm (http://www.badgerinsulatedpipe.com/Circulating-Pumps_c14.htm)
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Try bring up the differential up even though it is 14 degrees check the boiler temp after it fires at 171 and see how much lower it goes before it starts climbing up in temp just something else to check
I have noticed the stove go down to around 168 when it first starts to cycle. Will moving more water increase my efficiency at all? I think I remeber reading a thread on here and it was a sensitive subject for some....
I think I'm going to order one of those badgers Countryboy, thanks. I wanted to buy at least one extra pump to have on hand just in case, anyway. My 15-58 should work on my garage. 10 ft elevation and only about a 60-70 ft run (one way). I only have a water to air HX in there.
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That short term drop you are seeing is probably just all the water between OWB and FPHX, happens to me all the time; cause I only system the pump on when there is a call for heat in the house. In less than 5 minutes, the lines (50' run each way of 1" PEX) are up to temperature and I can begin pulling heat off of stove.
How about this for a setup (MINE ;)):
Water comes off of OWB (pumped by SS Alpha, set to AutoAdapt and happily pumps at 3 GPM), thru thermostatic bypass (sends water back to OWB if below 140) then to 60 plate FPHX
*On other side of FPHE, mechanical mixing valve (with outdoor reset, max temp into slab is 110f), thru a different Cast Iron Alpha (in AutoAdapt) and out to 2-zone (6 & 8 loops, heating 4000sf)
**ONLY COMPLAINT, was from wife the week it was -40f and the house kept losing a degree a day (til it was about 65, in the house) at which point kicked pump up to HIGH between FPHX and slab and everyone was happy again, after a few hours