2 questiosn Oveheat loop? getting most from storage

[markmudd]

New to wood boiler opeartion and this site. Wish I would have found it before I installed system.

I have a 150 BTU non-gassification indoor wood boiler in my garage (Royall Boiler model 6150) System has a 20x20 water to air heat exchanger in plenum (150K BTU rating depending on air/water flow rate)for my forced air heat. The heat exchanger is located above boiler with 1 inch copper supply that slopes towards the exchanger and 1" return lines back to boiler. I piped it up hoping that in event of pump failure /power outage, that the heat exchanger would thermosypon water thru to keep from overheating and blowing pressure releif valve.

Boiler has a 30 psi pressure relief and I also installed a 210 degree temp relief valve on piping above boiler for safety.

Also Have 450 gallon well insulated storage tank with 120 ' 3/4 copper heat exchanger in tank, Might have some theromsyphone action on piping to tank but not counting on it. the pipe up arrangement is the water rises out of boiler 4' to ceiling, travels horizontal about 20 ft and drops 4' to tank and copper loops in tank and back following same path. .

The heat exchanger and storage tanks are on separte supply and return loops. All controls are simple 1" ball valves so I can isolate each loop and use one or the other

have 3 speed grunfos pump, no check valve so it can themosyphon if needed

System works great so far. No problem getting tank temps to 170 /180 degrees

My questions are:

1. Do you experienced folks out there feel I need to install an oveheat protection loop with Auto valve and large size BTU heat dump to open up if temps/ pressure rises to dangerous level? It would keep me from losing water in an oveheat situation and repressurizing system.
I have a couple of times unplugged the pump to simulate power outage to see what happens and temps do not run out of control. It rises to about 190 ish and seems to top out there. Is there a situation that I should consider that I'm not with respect to overheating? heat exchanger valve should never be closed during boiler operation.

2. Trying to figure out best way to get most from my storage tank. I have been running pump on all speeds and it seems I can crank out most heat to house and tank simultaneously using medium to high pump speed and when I want to draw heat from tank just shut down the return valve from storage tank to slow the flow thu tank loops so it picks up the stored heat as it travels though loop This storage tank is all manually controlled with ball valve. I can adjust fan relay to run at various temps so I could get usuable heat out of 130 degree water if I did not have fire I have seen various configurations on storage tank piping on this , which appear much different and more sophisticated than my system.

any suggestions would be appreciated. Hope all this makes sense!

 

[sparke]

1. When you shut off the pump to test, was there a fair amount of wood in the boiler to simulate worse case scenario? Did the system thermosyphon to heat exchanger as expected? If you have tried this test more then once and it keeps the boiler from reaching temps 200* your power outage zone would seem adequate...

2. As you charge storage, you would typically start the pump slow and increase the speed as the delta T gap narrows (this I am sure of)... I am not sure which speed would be best when drawing. I would guess slow speed when tank temp is high and increase pump speed as tank temp drops.

I am not a heating tech so take this advice as an opinion, maybe someone qualified can confirm my assessment.

 

[Singed Eyebrows]

New to wood boiler opeartion and this site. Wish I would have found it before I installed system.

I have a 150 BTU non-gassification indoor wood boiler in my garage (Royall Boiler model 6150) System has a 20x20 water to air heat exchanger in plenum (150K BTU rating depending on air/water flow rate)for my forced air heat. The heat exchanger is located above boiler with 1 inch copper supply that slopes towards the exchanger and 1" return lines back to boiler. I piped it up hoping that in event of pump failure /power outage, that the heat exchanger would thermosypon water thru to keep from overheating and blowing pressure releif valve.

Boiler has a 30 psi pressure relief and I also installed a 210 degree temp relief valve on piping above boiler for safety.

Also Have 450 gallon well insulated storage tank with 120 ' 3/4 copper heat exchanger in tank, Might have some theromsyphone action on piping to tank but not counting on it. the pipe up arrangement is the water rises out of boiler 4' to ceiling, travels horizontal about 20 ft and drops 4' to tank and copper loops in tank and back following same path. .

The heat exchanger and storage tanks are on separte supply and return loops. All controls are simple 1" ball valves so I can isolate each loop and use one or the other

have 3 speed grunfos pump, no check valve so it can themosyphon if needed

System works great so far. No problem getting tank temps to 170 /180 degrees

My questions are:

1. Do you experienced folks out there feel I need to install an oveheat protection loop with Auto valve and large size BTU heat dump to open up if temps/ pressure rises to dangerous level? It would keep me from losing water in an oveheat situation and repressurizing system.
I have a couple of times unplugged the pump to simulate power outage to see what happens and temps do not run out of control. It rises to about 190 ish and seems to top out there. Is there a situation that I should consider that I'm not with respect to overheating? heat exchanger valve should never be closed during boiler operation.

2. Trying to figure out best way to get most from my storage tank. I have been running pump on all speeds and it seems I can crank out most heat to house and tank simultaneously using medium to high pump speed and when I want to draw heat from tank just shut down the return valve from storage tank to slow the flow thu tank loops so it picks up the stored heat as it travels though loop This storage tank is all manually controlled with ball valve. I can adjust fan relay to run at various temps so I could get usuable heat out of 130 degree water if I did not have fire I have seen various configurations on storage tank piping on this , which appear much different and more sophisticated than my system.

any suggestions would be appreciated. Hope all this makes sense!

This boiler is kind of unique in that it just has a U shaped tank of water over it & should tolerate a power outage better than others. I believe my Energy Mate boiler was the forerunner to your Royall. You probably don't need a dump zone. It appears this is a new install for you & I would keep a close eye on the chimney for creosote. Does yours run real high flue gas temps? If you have the room it would help to add a 500 gallon propane tank to your system, Randy

 

[markmudd]

Thanks for replys.

Yes, you are correct, this is a new install. Boiler and solar system has been on line about a month. It is a heavy boiler plate model with u shaped water jacket basically designed as a pressure vessel, with steel rods connecting inside and outside of water jacket together. The tag says the max pressure is 146 lbs so this thing will not get hurt from 30 psi pressure release as long as I don't continue to use it without water. The manual for this boiler does not require a oveheat loop unless local codes call for it. No codes to follow where I live but I want to be safe.

I was having creosoete issues on start up but when I adjusted aquastat temp up to 180 degree fan shut off , that took care of most of problem. I was too chicken on start up to run it at higher temps until I was sure how this thing would function. I plan to check my flue this weekend to see how it looks

When I did the test (turned off pump), the boiler was hot with a good fire. No problems. Also had one occasion after I fiddled with valves on storage loop that pump air locked and was not pumping for probably a couple of hours, again no problem even though boiler was up to temp with good fire. Unit has manual adjust air flow on boiler blower fan and it was not open more than 1/2 inch, so natural draft was minimal. If it was open to allow lots of air flow to get fire raging, I could see where temp could run out of control and pressure releif might have to activate. When I'm not around to tend fire, I keep natural draft opening shut down to about 1/2 inch. I plan to upgrade to the newer model fan that would completely shut off air when fan kicks off.

I would like to have pressurized storage, but I have a 450 gal non pressurized tank because I also have a 64 sq ft solar collector (drain down) which pumps out of tank.
I guess I could add pressurized storage along with this but I need to move on to other projects. Maybe someday?

So far I am impressed with this uits performance. I purchased used. Probably not as easy on wood as the more efficient gassification units but climate is pretty moderate in central mo compared to those in the northwoods. It is no worse than the forced air wood furnace it replaced as for as wood usage. I live in a rural area so the smoke is not an issue. Don't have to purchase wood so usage is not much of issue. Previous owner had to sell it cause he lived in small town and neighborhood got a petition to force him to remove. He had radiant floor heat and this thing idled most of time, so i'm sure nieghbors were jsutified in complaint. I plan to run a hot fire at all times if possible.

On a side note, I have had solar collector pump run on sunny days with temp in 50's and tank temp in 160 range with the solar controller set at 20 degree diff. I did not think I'd get much out of collector when boiler was fired up but maybe it will be better than anticipated. On moderate days I don't have to stoke fire in morning. I can adjust aquastat on fan relay to run fan at lower temp than 150 if needed. Sytstem is designed to bypass boiler/ heat excanger in summer for domestic hot water needs.

thanks again

 

[Singed Eyebrows]

Thanks for replys.

Yes, you are correct, this is a new install. Boiler and solar system has been on line about a month. It is a heavy boiler plate model with u shaped water jacket basically designed as a pressure vessel, with steel rods connecting inside and outside of water jacket together. The tag says the max pressure is 146 lbs so this thing will not get hurt from 30 psi pressure release as long as I don't continue to use it without water. The manual for this boiler does not require a oveheat loop unless local codes call for it. No codes to follow where I live but I want to be safe.

I was having creosoete issues on start up but when I adjusted aquastat temp up to 180 degree fan shut off , that took care of most of problem. I was too chicken on start up to run it at higher temps until I was sure how this thing would function. I plan to check my flue this weekend to see how it looks

When I did the test (turned off pump), the boiler was hot with a good fire. No problems. Also had one occasion after I fiddled with valves on storage loop that pump air locked and was not pumping for probably a couple of hours, again no problem even though boiler was up to temp with good fire. Unit has manual adjust air flow on boiler blower fan and it was not open more than 1/2 inch, so natural draft was minimal. If it was open to allow lots of air flow to get fire raging, I could see where temp could run out of control and pressure releif might have to activate. When I'm not around to tend fire, I keep natural draft opening shut down to about 1/2 inch. I plan to upgrade to the newer model fan that would completely shut off air when fan kicks off.

I would like to have pressurized storage, but I have a 450 gal non pressurized tank because I also have a 64 sq ft solar collector (drain down) which pumps out of tank.
I guess I could add pressurized storage along with this but I need to move on to other projects. Maybe someday?

So far I am impressed with this uits performance. I purchased used. Probably not as easy on wood as the more efficient gassification units but climate is pretty moderate in central mo compared to those in the northwoods. It is no worse than the forced air wood furnace it replaced as for as wood usage. I live in a rural area so the smoke is not an issue. Don't have to purchase wood so usage is not much of issue. Previous owner had to sell it cause he lived in small town and neighborhood got a petition to force him to remove. He had radiant floor heat and this thing idled most of time, so i'm sure nieghbors were jsutified in complaint. I plan to run a hot fire at all times if possible.

On a side note, I have had solar collector pump run on sunny days with temp in 50's and tank temp in 160 range with the solar controller set at 20 degree diff. I did not think I'd get much out of collector when boiler was fired up but maybe it will be better than anticipated. On moderate days I don't have to stoke fire in morning. I can adjust aquastat on fan relay to run fan at lower temp than 150 if needed. Sytstem is designed to bypass boiler/ heat excanger in summer for domestic hot water needs.

thanks again

Yes, these are powerfull boilers & even though about 50 percent efficient they easily put out rated heat. If you put some anthracite in with the wood this puts out some awsome heat. These will burn up the creosote unless you idle it. Good luck, Randy

 

[in hot water]

There were a bunch of those Royalls scattered around SW Missouri where I live. Chiles Power Systems provided a system with a plywood/ EPDM with coils for solar, wood, DHW and radiant. Most had the early SolarRoll collectors.

I've dismantled 4 of those systems, each had a Royall, as they eventually sprouted leaks in the copper coils. Several had pond loops and early GEO systems tied into them also.

I ended up with a Royall for my place and ran it several years until I got a deal on my current EKO. It was a solid performer and actually had some listings so insurance companies looked favorably on it. I eventually gave the Royall to a former employee and it runs still. It has provided maybe 20 years of service.

I bought a brand new Royall about 4 years back and installed it for a cabinet shop nearby. It's in Amish country and he blends scrap hardwoods and buys bags of coal from the Amish buggy shop to blend in.

I worried about overheating as it has a fan but no damper to shut down, so it always has a source of air even with the power down. I never did have an overheat condition and we get frequent power outages here with ice storms, as you may well know.

Not much has changed with the boiler over the years, made in Wisconsin as I recall.

hr

 

[Singed Eyebrows]

Yes, these are ASME. I put petroleum coke in mine & told the supplier it wasn't any better than anthracite, he said"you didn't get it lit". I tried about 2 more times & it finally caught, the amount of heat was awesome! I believe these started as Energy Mate boilers out of Tomah Wis, they then went to Franksville Wis & I toured the factory & talked to the engineers. They redesigned the firebox with much more grate area & straight sides for hard coal burning along with shaker grates. The one bad point with this boiler was it was capable of flue gas temps that would cause the stove pipe to glow red. If the outside is 1400 degrees the center is pushing 3000 degrees. The engineer just said don't worry about it the creosote needs to be burnt up. It looks like they went back to a V grate & anthracite doesn't like V grates so it's best for wood or a little coal mixed in, Randy

 

[markmudd]

Royall now offers a blower fan with full shut off damper for this boiler, which I think I will try. $180. They claim 10% less wood usage with it. Best of all it would minimize possiblility of overheating. So far the flue temps are not as hot as my old wood furnace but I've noticed when loading wood the fire wants to run and the flue will get hot if you keep door open

They have not changed this model much in last 25 years as I understand it. I only paid $1200 bucks for this unit which is 7 years old I think, so if it only lasts a few years I will not get burnt too bad and would look at updating to something else or mabey going with another one of these. Very easy to operate . Brand new they are about $4000, but no tax credit available. The way this thing looks it will last many more years. Appears to be quality product.

I'm not sure I could even get coal in central MO. Anybody know where. It would be nice to have for longer burn time since I have no other backup.

 

[in hot water]

Where in Missouri? I travel Hwy 13 from Springfield to KC a bit. I always see Amish buggies along the road. Where there are Amish you can usually find coal. Or walk the tracks where the coal trains stop,they tend to spill some from the coal cars.

hr

 

[markmudd]

near Fulton

I know there are some Amish down around
Versailes and north of Columbia near Clark. I might check this out.
thanks