LL AA-220 Relocation

hotblast1357 wrote: ↑

Thu. Nov. 15, 2018 7:56 am

Well apparently it is not if it’s shutting off on the high limit..

I think what larry meant was, having that jumped 24/7 is going to make your stokers run 24/7 cuz they think it’s a call for heat?

Which is why he suggested moving it to the other connection.

We on same page, I guess I just didn't word it correctly

swyman wrote: ↑

Thu. Nov. 15, 2018 7:54 am

Just a little confusing because I understand what Larry mentioned that with zone 1 being jumpered the tt might send a signal to keep the boiler firing?

I meant firing until it hits the high limit. I don't think it is a good idea to run the boiler up to the high limit all the time. You need to eliminate the jumper that is effectively a permanent heat call. Then all will be well. Unless, as you suggest, you have a section of underground pipe that is subject to freezing if not permanently kept in motion. But for that case what happens if the power goes out? You need to insulate the section that might freeze, so it can't freeze, even during an extended power outage.

Many different ways to insulate pipe. A "clean" way is using something like this foil/foam to wrap the pipe, then wrap with unfaced insulation and cover with waterproof covering, like insulating a fresh water pipe (but don't use heat tape)
Or you can make a box around it with pieces of 2" foamboard glued together. High quality HVAC tape is a reliable assembly tool (wrap all the way around so it sticks to itself). Fill the foam 'box' with unfaced insulation.

You WANT a thermostat on whatever zone. Jumpering it is okay for a TEST, but there are many reasons to have control over it for temp or turning on/off.

Triple Aquastats can be confusing as to how they work. Study this pic, which helped me understand them

lsayre wrote: ↑

Thu. Nov. 15, 2018 8:30 am

I meant firing until it hits the high limit. I don't think it is a good idea to run the boiler up to the high limit all the time. You need to eliminate the jumper that is effectively a permanent heat call. Then all will be well. Unless, as you suggest, you have a section of underground pipe that is subject to freezing if not permanently kept in motion. But for that case what happens if the power goes out? You need to insulate the section that might freeze, so it can't freeze, even during an extended power outage.

It would take a while to freeze if there was/ has been power outages. I am never to far from home so I am always able to get the generator going to keep the house stable. I agree with you and will make the change to the zone 1 circulator.

CoalisCoolxWarm wrote: ↑

Thu. Nov. 15, 2018 8:41 am

Many different ways to insulate pipe. A "clean" way is using something like this foil/foam to wrap the pipe, then wrap with unfaced insulation and cover with waterproof covering, like insulating a fresh water pipe (but don't use heat tape)

foilfoam.png

Or you can make a box around it with pieces of 2" foamboard glued together. High quality HVAC tape is a reliable assembly tool (wrap all the way around so it sticks to itself). Fill the foam 'box' with unfaced insulation.

You WANT a thermostat on whatever zone. Jumpering it is okay for a TEST, but there are many reasons to have control over it for temp or turning on/off.

Triple Aquastats can be confusing as to how they work. Study this pic, which helped me understand them

Triple Aquastat function graph.gif

Thank you CICXW!

What is the high limit set to at this point...
Is it still at 180*...

CapeCoaler wrote: ↑

Thu. Nov. 15, 2018 9:19 am

What is the high limit set to at this point...
Is it still at 180*...

195 high

Wouldn't it be interesting to discover if all along it was a distribution problem (or multiple distribution problems) and it was never a boiler problem?

Don’t we already know it was deff a problem running it out in the barn?

The barn loop can only deliver 37,500 BTUH if it is ~0.863" ID, or 60,000 BTUH if it is ~1.022" ID, for the case of 20 degree Delta-T. Not enough BTUH to heat the garage and the house which used to be on the receiving end. But now that the boiler is in the house and the 1" copper pipe to the house can carry as much as 103,500 BTUH things are quite different. It is a distribution thing, and not a boiler thing. The barn is still only capable of receiving 37,500 to 60,000 BTUH through the 480 foot loop, but everything else can receive much more now that the distances traveled are greatly reduced.

Well Larry please explain how the outdoor wood boiler and the corn boiler DID heat the house and garage from the barn?

hotblast1357 wrote: ↑

Thu. Nov. 15, 2018 8:28 pm

Well Larry please explain how the outdoor wood boiler and the corn boiler DID heat the house and garage from the barn?

I wonder if the exact same circulators were in play back then. And if the garage was part of the equation back then. And if the house was the same size back then. And if the zones were the same back then. And the run lengths were all the same back then. Etc...

I.E., back then, was the only change that was made that of removing the wood boiler and replacing it at the same location with the coal boiler, with all else staying the same.

Here’s what I’m 99% sure on..

Same underground piping.

House same size minus addition above new boiler room, which wasn’t there when we first had the AA-220 installed in the barn.

Garage was still there..

I do not know what circulator he was using..


So what your saying larry... is instead of doing all this work moving the boiler, he could of just installed a better bigger circulator?

hotblast1357 wrote: ↑

Fri. Nov. 16, 2018 5:42 am

So what your saying larry... is instead of doing all this work moving the boiler, he could of just installed a better bigger circulator?

Possibly, but within limits. This amazingly efficient monster of a circulator (the worlds most efficient?) would have increased his ability to squeeze heat through the 480 foot loop by (on first quick look) a factor of about 1.67X:

http://aquamotionhvac.com/pumps/am99-fl-am99-fvl/

But even 1.67X more heat delivery would not move 153,000 BTUH through his 480 foot run without experiencing about a 45 degree Delta-T for the case of 1.022" ID or a roughly 60 degree Delta-T for the case of 0.863" ID. Albeit that I still contend that this sort of Delta-T doesn't likely matter as long as the boiler can handle it.

What may well matter though is that at max output from this circulator the PSI pressure increase in his system would approach that required to open his boilers pressure relief valve. You can only squeeze so much heat through a long thin pipe, and doing so by brute force has potential consequences.

I just looked at one of the very first posts ever made by swyman, and in it he states that his forest eating wood boiler was operating with a 55 degree Delta-T (which for all we know may have been on the conservative side of things). In the very same thread Scottscoaled rapidly assesed the situation and told him it would not work, and also explained that the very best he was remotely capable of squeezing through the long run of 1" PEX was about 33% of his wood boilers likely honest output capability. Scottscoaled sensed doom for the LL AA-220 project very early on (April 14, 2015), and made it clear to swyman. No one else apparently did. The rest of us simply thought that a 220,000 BTUH input coal boiler is a monster and coal must always be superior to wood. We never considered that no matter how much of a monster the boiler is, you simply can't squeeze blood out of a turnip. My hat is off to Scottscoaled for trying to right the ship before it sank.