Outdoor Wood Furnace Info

All-Purpose OWF Discussions => Plumbing => Topic started by: mw10737 on September 22, 2012, 04:46:49 AM

Title: new pumps
Post by: mw10737 on September 22, 2012, 04:46:49 AM
guys,  just added (2) pumps to my empyre system.  I stacked two gunderfous 26-99 pumps, feeding out of furnace with 1 1/4, then pex is 1".  Running 110ft to house .  I can tell you this, its amazing how quick recovery is with furnace and heat exchanger for DHW.  I think the wood usage has cut in half... Its amaxing getting that return water back there faster and taking less heat of of return... makes a huge diffirence.  VERY HAPPY with results .  Can run furncae and take showers and i only see maybe a 10 degree drop in return water temp. Boiler temp normally doesnt even drop.  Guess stacking these two pumps is the ticket..    opinions????
Title: Re: new pumps
Post by: RSI on September 22, 2012, 07:54:08 AM
You added 2 more? How many total do you have now? One of those should be enough normally.
How many heat exchangers do you have in the house? Do you have a plate heat for the DHW? if so what size?
Title: Re: new pumps
Post by: Scott7m on September 22, 2012, 09:46:06 AM
The flow of water has no bearing on the btu load of your home or domestic water needs, you can circulate the water 200gpm or 10gpm and your home still requires the same amount of btu

I have no idea why your wood usage seems lower, perhaps because it's so mild right now?
Title: Re: new pumps
Post by: RSI on September 22, 2012, 07:38:05 PM
The flow of water has no bearing on the btu load of your home or domestic water needs, you can circulate the water 200gpm or 10gpm and your home still requires the same amount of btu

I have no idea why your wood usage seems lower, perhaps because it's so mild right now?
If using a 10 plate and a small pump there will only be a couple GPM at the most and running hot water will take all the BTU's available. Going to a larger pump(s) will force the water through at a higher rate giving enough BTU's to keep up with demand.

If that is what is happening, getting a bigger plate would allow to run one smaller pump and save $20 or $30 a month on electricity.

As far as wood usage, it might be from getting a lot better mixing in the boiler tank.
Title: Re: new pumps
Post by: Scott7m on September 22, 2012, 08:25:12 PM
I understand that but I doubt he has a 10 plate, but half the wood? 

I have used 10 plates and 20's here at home just trying to see if there was a difference.  The 20 made a bit hotter domestic water, I've also used several different pumps and I've never noticed any making a difference in efficiency
Title: Re: new pumps
Post by: RSI on September 22, 2012, 09:08:04 PM
How many feet of pex were there with the 10 plates and what pump was on the system.
I have seen a system with a 10 plate and about 150' from the house that the boiler water was under 100 degrees coming out of the plate.
Title: Re: new pumps
Post by: mw10737 on September 22, 2012, 09:22:19 PM
Guys.  Using A 20 plate for DWH.  And have a 12X12 (90,000 BTU) in my garage,, and a 20X24 in my house furnace.  Problem last winter was a huge temp drop out of my registers when showers were going. So therefore I wanted to increase flow.  Now furnace can run and showers going... washing clothes.. dishwasher going. and I have no temp drop in registers.  Basically what I think is happening is now that the flow is much higher and  im not losing near the heat from the 20 plate.. and is getting the water back to boiler quickly and not dropping boiler temp more than 6-7 degrees after 5 people take showers,  and yes it is using 1/2 the wood.  It only makes sense though.. if water can get back to boiler with minimal heat drop it isnt going to drop boiler temp that much....hence not having to run near as much, therefore the less wood consumption... this thing is working great.

I have 3 pumps on boiler, but only run stacked pumps in the fall-winter..... and through the spring and summer will run the smaller single pump for DHW only..  tell me if what im saying doesnt make sense,,, but it is working good so far. Im runnung 150 ft to house then another 100 ft before i get to basement.  So I have a long distance to run. 

Also I have both my  furnace blowers and my pumps and wood furnace is running off of a wind generator with battery bank.  And so far with the dual pumps running it hasnt seem to use that much more from my inverter. 


I have a temp probe on feed line and return line.;  the most i can get as a temp drop running showers and furnaces is 7 degrees.   too me that is extreamly good...  keep the feedback coming ..     :)
Title: Re: new pumps
Post by: RSI on September 22, 2012, 09:26:59 PM
So you have about 500' of 1" pex and 3 heat exchangers? Are there any zone valves or many elbows?
What model is the original pump?
Did it always work the same way or has it been getting worse
Title: Re: new pumps
Post by: mw10737 on September 22, 2012, 09:31:10 PM
6 elbows..  always worked the same.  was a smaller pump... max flow of 17GPM
Title: Re: new pumps
Post by: RSI on September 22, 2012, 09:32:08 PM
Grundfos 15-42?
Title: Re: new pumps
Post by: mw10737 on September 22, 2012, 09:35:37 PM
RSI:  Here are the specs

Three Speed High Performance Circulating Pump

•Removable Integrated Check Valve
•Built-in motor protection for longer life
•Quiet and low power consumption
•Prevents thermal siphoning
•Pump Housing: Cast Iron
•Voltage: 115 V, 60 HZ. Power: 100/70/55w. Motor: 2 Pole, Single Phase
•Min Fluid Temp: 36° F (2° C). Max Fluid Temp: 230° F (110° C). Max Flow: 17.9 (U.S. GPM). Max Head: 19 feet (head). Max Working Pressure: 145 PSI
•Insulation Class: H 356° F (180° C)


Vendor: Stiebel Eltron

Title: Re: new pumps
Post by: mw10737 on September 22, 2012, 09:37:18 PM
Do you think it shouldnt work?  does what im saying make sense? 
Title: Re: new pumps
Post by: RSI on September 22, 2012, 10:40:15 PM
That is a Grundfos 15-58.
That is too small for that much pipe. 
I would have thought that one 26-99 would have been sufficient. Have you tried just running one of them by itself?
Title: Re: new pumps
Post by: Scott7m on September 22, 2012, 10:50:49 PM
No..  Because its still pulling off the same # of btu to heat your water and your home, the amount of heat your applications require did not change. 

Example.....   Let's say it takes 50,000 btu to heat ur home for an hour.  The stove still had to produce the same number of btu, the speed of the water may have increased lowing your delta t across each appliance but the same # of btu were used.  Let's say before you had a delta t of 30, and now its 10, you are sending the water back to the furnace hotter than previously, but there is more water moving, so no change. 

Would it improve things like registers cooling during showers? Yes. Because more gpm are moving bringing more btu's in, lowering the delta t
Title: Re: new pumps
Post by: Scott7m on September 22, 2012, 10:54:00 PM
You def had to small of a pump for the distance....  Maybe ur flow was so crazy slow you had huge delta t's but I still can't see it burning less wood, half would be s miracle, I'm just thinking, if saving half the wood were so simple, why don't we all just install the biggest pumps we can? 
Title: Re: new pumps
Post by: mw10737 on September 23, 2012, 07:20:29 AM
Yes RSI, i did run just one of the 26-99 and it worked good, but after i added the 2nd 26-99 the wood consumption dropped.

 Scott... totally understand what your saying, i think water is returning so quickly to boiler that my delta is so low now that it stays within my set 10 degree differental and not requiring the stove to run as much.  i honestly didnt think it would make this much diffirence adding both 26-99 pumps,  but it its so far.   

Also when there is no demand for water there is no delta... it just sits and loops at same temp  return and feed both temp.

Title: Re: new pumps
Post by: RSI on September 23, 2012, 12:16:02 PM
The only thing that makes sense is if the cold water is returning close to the temperature sensor and causes the boiler to cycle a lot more than it should and possible overheat the water in the rest of the boiler.

If just adding the extra pump made the wood usage go down that much you would be better off putting small pump like a 15-58 that just circulated the water in the boiler. (just pumping from supply to return connections at the boiler) It will move a lot more water that the extra 26-99 is pumping through the house loop.
Title: Re: new pumps
Post by: Scott7m on September 23, 2012, 01:22:57 PM
The only thing that makes sense is if the cold water is returning close to the temperature sensor and causes the boiler to cycle a lot more than it should and possible overheat the water in the rest of the boiler.

If just adding the extra pump made the wood usage go down that much you would be better off putting small pump like a 15-58 that just circulated the water in the boiler. (just pumping from supply to return connections at the boiler) It will move a lot more water that the extra 26-99 is pumping through the house loop.
:post:

That could be it, but the sensor ain't near the return so I donno.
Title: Re: new pumps
Post by: mw10737 on September 23, 2012, 01:43:11 PM
Sensor is on opposite end of boiler tank..up.behind control panel if I remember correctly. 
Title: Re: new pumps
Post by: mw10737 on September 23, 2012, 01:49:45 PM
 I don't.think.it's a false reading on.boiler because my temp probes at furnace and at entry to house are matching boiler control temps .that tells me basically that I'm not getting a false reading

Been 4 days since I added any wood.. and its been in the upper 20s. Low 30s at night and 50-60s during the day... before I was filling it ever 30 hrs at this temp outside
Title: Re: new pumps
Post by: tanner on September 23, 2012, 08:03:01 PM
I had a question about a pump i figerd sence every body was talking about one i figerd id ask.  I have a 4135 legend gona have abt 65 ft of 1inc pex i was wondering what size and brand of pump i would need. 
Title: Re: new pumps
Post by: Scott7m on September 23, 2012, 08:11:29 PM
I usually install wasser 3 speed pumps to give folks some flexibility
Title: Re: new pumps
Post by: RSI on September 23, 2012, 08:14:04 PM
I had a question about a pump i figerd sence every body was talking about one i figerd id ask.  I have a 4135 legend gona have abt 65 ft of 1inc pex i was wondering what size and brand of pump i would need.
My favorite options for pumps are Grundfos 15-58 for smaller pumps and B&G PL36 for larger pumps.
It sounds like the 15-58 would work for you with only that much pipe unless you have a lot of restrictions in the house.
Title: Re: new pumps
Post by: Scott7m on September 23, 2012, 08:27:54 PM
I had a question about a pump i figerd sence every body was talking about one i figerd id ask.  I have a 4135 legend gona have abt 65 ft of 1inc pex i was wondering what size and brand of pump i would need.
My favorite options for pumps are Grundfos 15-58 for smaller pumps and B&G PL36 for larger pumps.
It sounds like the 15-58 would work for you with only that much pipe unless you have a lot of restrictions in the house.

Love the 15-58 but hate selling one to someone who's project I've not seen, I sold an 007 to a guy last year who was only going 45 feet, it was straight over a steep hillto his boiler and then he has 1/2 pex inside lol sheww
Title: Re: new pumps
Post by: RSI on September 23, 2012, 08:39:13 PM
An 007 only can do about 10' of head pressure and a 15-58 can do 19 feet.  You can always add a second 15-58 if it is too small and it is equivalent to a large pump.
Title: Re: new pumps
Post by: RSI on September 24, 2012, 07:38:21 AM
RSI:  Here are the specs

Three Speed High Performance Circulating Pump

•Removable Integrated Check Valve
•Built-in motor protection for longer life
•Quiet and low power consumption
•Prevents thermal siphoning
•Pump Housing: Cast Iron
•Voltage: 115 V, 60 HZ. Power: 100/70/55w. Motor: 2 Pole, Single Phase
•Min Fluid Temp: 36° F (2° C). Max Fluid Temp: 230° F (110° C). Max Flow: 17.9 (U.S. GPM). Max Head: 19 feet (head). Max Working Pressure: 145 PSI
•Insulation Class: H 356° F (180° C)


Vendor: Stiebel Eltron

I  just noticed this and apparently was replying from my phone. I missed the bottom line before. It is a chinese copy of a Grundfos 15-58 but should move pretty much the same amount of water.