Gas boiler, Indoor boiler behind garage, storage, one line diagram

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WoodWacker

WoodWacker

Member
Mar 9, 2013
40
Maine
Hearthers,

Back to the drawing board. I think I've got the blunt of the system thought of but open to any input to make it mo bettah. My plumber is taking care of the gas boiler and I'll be adding the wood system via oversized heat exchanger. I plan on using Runtal panel heaters, slightly over sized to accommodate lower temp heating. I've got an 8x12 boiler room(footers currently being poured) behind garage that will hold two 500 gallon upright tanks with "open" maybe closed valve head tank. I'll have to see if I have enough head tank capacity to keep head tank valve closed with air gap. Tasso boiler will make the warm. Obviously a rough sketch and rough area/location of boiler. I've read up a bit on NFPA 211 for minimum clearances. Class A chimney for 2" clearance against wall. I'll run 24ga steel sheet with 1" air gap to make my minimum clearance to boiler sides and back at 12", if that's still code. Electric baseboard backup to keep room warm during vacation. Air handler located in boiler room vented to garage for heat only when boiler is online. See attached system drawing.

upload_2015-10-21_22-42-25.png




upload_2015-10-21_22-34-29.png
 
Last edited:
WoodWacker said:
Hearthers,

Back to the drawing board. I think I've got the blunt of the system thought of but open to any input to make it mo bettah. My plumber is taking care of the gas boiler and I'll be adding the wood system via oversized heat exchanger. I plan on using Runtal panel heaters, slightly over sized to accommodate lower temp heating. I've got an 8x12 boiler room(footers currently being poured) behind garage that will hold two 500 gallon upright tanks with "open" maybe closed valve head tank. I'll have to see if I have enough head tank capacity to keep head tank valve closed with air gap. Tasso boiler will make the warm. Obviously a rough sketch and rough area/location of boiler. I've read up a bit on NFPA 211 for minimum clearances. Class A chimney for 2" clearance against wall. I'll run 24ga steel sheet with 1" air gap to make my minimum clearance to boiler sides and back at 12", if that's still code. Electric baseboard backup to keep room warm during vacation. Air handler located in boiler room vented to garage for heat only when boiler is online. See attached system drawing.

View attachment 164752



View attachment 164749
Click to expand...
==================================================================================================

FIRST:

You need to order a couple of books from AMAZON.

PUMPING AWAY by Dan Holohan
ClASSIC HYDRONICS by Dan Holohan


Then you need to fix your plumbing!!

You need two things. number one is a bypass loop on your
propane boiler. This is done to return a portion of this boilers
hot water volume back to the boiler sump to keep the boiler hotter.

You also need to do the same thing for your wood boiler.
this accomplish the same thing by saving heat in the wood boiler
and keeping the boiler water hotter at all times.

(You will not want to oversize your panel radiators as you will be pushing too much cooled water back to the boiler or boilers!! you only want a 20 degree temperature differential).

You can use a smaller plain steel radiators with a one pipe system where each plain steel radiator would also have its own manual thermostat BTW. Much less money spent too and you can buy beautiful radiator covers at a low cost per foot.

Number two is to install the "circulator" or "circulators" above the boilers "Pumping Away" from the boilers.

Doing this allows you to power purge the heating loops and push
all the air bubbles out using about three ounces of Dawn Dish Soap to break
up the air bubbles.

The other questions are:

How many stories is your home??

How big are your heating loops???
=======================================================================

A couple of other things:

Why do you have a valve on the expansion tank vent line ????? NOT GOOD!!

Your steel expansion tank is not going to work properly period!!!

WHY do you not have the expansion tank line coming off the top of the wood boiler??????? I see no airtrol valve noted on the feed line to the tank(the airtrol is threaded directly into the base of the steel expansion tank.

You cannot get rid of trapped air the way you have it plumbed in the diagram, the vent line must come off the top of the wood boiler!!

Your storage tanks will not work the way you have them drawn as they will be bypassed. They need to be plumbed in series not series parallel.

IF you purchase the properly sized expansion tank and airtrol fitting you will be able to
use it for both systems and still have a closed system on the propane fired boiler side of your plumbing and if you have an air scoop and bladder tank you can eliminate that mess and the automatic air vents that fail over time and leak.

Do you have an airtrol valve in the steel expansion tank feed line that allows the air bubbles to enter the steel expansion and be trapped there?

The thing is that the steel expansion tank MUST have a 2/3 water to 1/3 air volume in order to work with the proper sized airtrol valve. unless your steel expansion tank is vented to air (PROPERLY) it must be a sealed system in order to maintain a minimum of 12 PSI in the system.

Using that size tank will require the larger B+G Airtrol valve and manual air vent tubing to properly balance the system.

In order to use the steel expansion tank properly you need an ASME tank and it must be sized properly for the systems total water volume.


You also need to have a tank gauge installed in the side of the expansion to monitor the water level in the steel expansion tank.

If you intend on using a plain steel expansion tank of this size you must plan on having
120 gallons of water in the tank to have the proper 2/3 water 1/3 air ratio to absorb any air bubbles. You will need a closed system to do this properly with the plain steel expansion tank. BTW a diaphram tank will cost you much more money and a steel expansion tank hung in the ceiling has no moving parts and allows you enjoy not having to bleed air as long as its piped properly.



I would like to ask which brand of wood boiler you own? If you fill your wood boiler half full of fire brick like I did it creates a huge amount of thermal mass keeping the fire hotter and the water hotter at all times.


Please order these two books before you do anything!!!

Your system needs to be properly plumbed and the storage tanks connected properly to the system as the series parallel plumbing diagram you have is not going to help you one bit as the the system will not work.

I only want you to succeed my friend,
 
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I will have an auto vent on the high side of my wood boiler water loop that will remove air. Head tank is designed as open. May layer with oil or if I have enough compress-ability in the tank, I'll close gooseneck at low temp, add slight air/nitrogen pressure and heat system. Run as low pressure closed. Tanks old propane tanks, but are missing ASME tags.

One concern with pump location. I may want my primary loop pump in front of my heat exchanger for my Condensing gas boiler. In the event my heat exchanger gets plugged, I won't cavitate the pump.
 
WoodWacker said:
I will have an auto vent on the high side of my wood boiler water loop that will remove air. Head tank is designed as open. May layer with oil or if I have enough compress-ability in the tank, I'll close gooseneck at low temp, add slight air/nitrogen pressure and heat system. Run as low pressure closed. Tanks old propane tanks, but are missing ASME tags.

One concern with pump location. I may want my primary loop pump in front of my heat exchanger for my Condensing gas boiler. In the event my heat exchanger gets plugged, I won't cavitate the pump.[/QUO



=============================================================================================
You want your pumps to pump away from the boilers, both of them.

By having an autovent there your going to starve your "circulator" and it will cavitate.

You cannot use an autovent with an open tank system.
Please order the books I told you about before you make
a costly mistake.

Water does not compress, by compress what do you mean.
Click to expand...
 
Last edited:
I didn't read the whole long winded response above, but the temp going back to the boiler doesn't matter. that's what the cold temp protection is for. It will mi make sure the water going to the boiler is warm enough.
 
The tanks can be plumbed parallel and will only be bypassed when the house is calling for heat and the boiler
is running witch is good for when the storage is cold. Im no expert but i think Leon needs to read those book he is recommending.
 
im not familier with how to plumb it but you do need to bypass the gas boiler when its not running or you will be wasting heat.
 
woodsmaster said:
I didn't read the whole long winded response above, but the temp going back to the boiler doesn't matter. that's what the cold temp protection is for. It will mi make sure the water going to the boiler is warm enough.
Click to expand...

===============================================================================================

The temperature of the water returning to the wood boiler or
the propane boiler does matter.

You want to prevent thermal shock with too cold return water
entering the boiler to be reheated.

Thats why a bypass line helps in keeping the boilers hot and
reduces fuel consumption whether it is propane, wood or coal.

The water storage will not work as the water mass is not being curculated an cannot be the way it is designed.

If your going to do anything use the 1,000 gallons of thermal mass the right way and
pipe the tanks in series and circulate the water through the wood boiler with a small volume circulator on a timer.

Running the Taco circulator with B+G circuit setter set to bypass 8 gallons per minute for an hour every two hours moves 480 gallons of water every two hours and this allows you to have more hot water without a lot of work.
 
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leon said:
===============================================================================================

The temperature of the water returning to the wood boiler or the propane boiler does matter.

You want to prevent thermal shock with too cold return water entering the boiler to be reheated.
Thats why a bypass line helps in keeping the boilers hot and reduces fuel consumption whether it is
propane, wood or coal.
Click to expand...

There is already a bypass line on his wood boiler in his diagram, and I doubt very much a bypass line on the LP boiler accomplishes any fuel savings or is called for in the install instructions for it.
 
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I would consider piping the Gas boiler primary secondary, and not passing heated water thru the LP boiler. what type of boiler is the LP boiler and what model is the wood boiler?
the expansion looks ok. you are pulling from the Point of no Pressure change. I would consider if you can putting the heat delivery (from the wood Boiler) and heat extraction piping (to the HX) pipes separate on the Tanks, or at least pipe them thru a low loss header at the top and bottom of the tanks to prevent the LK 810 from pushing heated water thru the HX rather than the storage tanks. you could use instead of a 007 use a VS pump to deliver the proper temp to the heating loop without over pumping and mixing the storage tanks.
do not put a bypass loop on the LP boiler. it works with leon's system because he only has one zone, so the boiler loop never has to deal with varying conditions.

I don't have the time to deal with the rest of the assertions above.
karl
 
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WoodWacker said:
I will have an auto vent on the high side of my wood boiler water loop that will remove air. Head tank is designed as open. May layer with oil or if I have enough compress-ability in the tank, I'll close gooseneck at low temp, add slight air/nitrogen pressure and heat system. Run as low pressure closed. Tanks old propane tanks, but are missing ASME tags.

One concern with pump location. I may want my primary loop pump in front of my heat exchanger for my Condensing gas boiler. In the event my heat exchanger gets plugged, I won't cavitate the pump.
Click to expand...

I would suggest putting the pump after the LP boiler as Leon suggested. While there is a lot there to digest from him, putting the pumps after the boiler is helpful for removing air and purging the system. There are several other benefits as well. Do you have air elimination and expansion for the LP boiler loop?
 
leon said:
===============================================================================================

The temperature of the water returning to the wood boiler or
the propane boiler does matter.

You want to prevent thermal shock with too cold return water
entering the boiler to be reheated.

Thats why a bypass line helps in keeping the boilers hot and
reduces fuel consumption whether it is propane, wood or coal.

The water storage will not work as the water mass is not being curculated an cannot be the way it is designed.

If your going to do anything use the 1,000 gallons of thermal mass the right way and
pipe the tanks in series and circulate the water through the wood boiler with a small volume circulator on a timer.

Running the Taco circulator with B+G circuit setter set to bypass 8 gallons per minute for an hour every two hours moves 480 gallons of water every two hours and this allows you to have more hot water without a lot of work.
Click to expand...

He does have a bypass loop and loading valve in the diagram to prevent thermal shock. even if his hx pulls the water down to 70 its not going to affect the boiler one bit..
 
Its basically how I have mine plumbed only I have a pump for each zone rather than a primary loop. Works great for me. Instant hot water when the boiler gets to temp. Any extra heat goes to storage. Just make sure when plumbing storage parallel that your pipes are level and equal size and length to make sure you get the same flow threw each tank.
 
maple1 said:
You're not alone.

What wood boiler are you using? Is it pressurized? Or an open boiler?
Click to expand...

It's a Tasso Universal triple pass cast iron boiler. All is good for pressure, however, I do not have ASME certs on my homemade tanks. Once I spray foam them, the ASME tags are hidden anyway. I probably could get away with pressurization, however I didn't want to design it that way.
 
Clarkbug said:
I would suggest putting the pump after the LP boiler as Leon suggested. While there is a lot there to digest from him, putting the pumps after the boiler is helpful for removing air and purging the system. There are several other benefits as well. Do you have air elimination and expansion for the LP boiler loop?
Click to expand...

Yes the LP boiler will be done by a professional plumber with many years experience. He's going to plumb the heat exchanger for me and I'll do the wood boiler side of things.
 
Karl_northwind said:
I would consider piping the Gas boiler primary secondary, and not passing heated water thru the LP boiler. what type of boiler is the LP boiler and what model is the wood boiler?
the expansion looks ok. you are pulling from the Point of no Pressure change. I would consider if you can putting the heat delivery (from the wood Boiler) and heat extraction piping (to the HX) pipes separate on the Tanks, or at least pipe them thru a low loss header at the top and bottom of the tanks to prevent the LK 810 from pushing heated water thru the HX rather than the storage tanks. you could use instead of a 007 use a VS pump to deliver the proper temp to the heating loop without over pumping and mixing the storage tanks.
do not put a bypass loop on the LP boiler. it works with leon's system because he only has one zone, so the boiler loop never has to deal with varying conditions.

I don't have the time to deal with the rest of the assertions above.
karl
Click to expand...

Karl, Thanks, this is some good info I was looking for.

I'm going to be using a Viessman Vitodens 100. Currently I only have 1 tap on each of the top's of my tanks and the same on the bottom. 1 1/4" NPT. I didn't put this in my thread earlier but, I think I can run water from wood boiler to tanks and not to HX because my HX is approx 6' lower than the bottoms of my tanks. I don't think the LK810 will push hot water almost 15' lower than my tank tops. At least that is my theory, please tell me if I'm mistaken. It will recirc just tanks (I hope), unless a zone is called upon. Each of my branches for zones have circulators.

Onto the wood boiler circulator. I chose the 007 because upon a zone request, the 007 starts at full bore for 30 seconds, giving it enough volume to make it(40' 1 1/4 insulated pex) to heat the HX before a zone pump kicks on. Then it will tone back as DeltaT across HX is decreased. VS is variable speed I assume? Which pump do you recommend? I prefer the theory just as you say: "proper temp to the heating loop without over pumping and mixing the storage tanks." What are the inputs to vary the speed of the VS pump? As my temp drops, I want to utilize as much heat from tanks as possible, as most do. I want to be able to add the last drop of heat from my tanks, use the hx as a preheater for Vitodens, until I reach a minimum tank temp switch via Aquastat to control 007/VS circ. If that makes any sense. Haha. Once I learn my return temp from panel heaters, I can adjust my tank aquastat to just above that temp, in turn, should open, and not allow for anymore pumping via 007.

I'm interested in the VS. What brand spec sheets should I be looking at?

Thank you,
WW
 
WoodWacker said:
It's a Tasso Universal triple pass cast iron boiler. All is good for pressure, however, I do not have ASME certs on my homemade tanks. Once I spray foam them, the ASME tags are hidden anyway. I probably could get away with pressurization, however I didn't want to design it that way.
Click to expand...

My thought was that if that is not an open boiler, you should keep your entire system closed (pressurized).

Then you might not even need to use a heat exchanger - you could maybe change the HX in your diagram to close T's.

If the boiler is an open (non-pressurized) boiler , you should isolate it from the rest of the system with a heat exchanger. i.e., there should be an exchanger between your boiler & the rest of the system - including the storage tanks. I wouldn't want my storage tanks to be open - too much corrosion potential. That corrosion potential would also be presented to the rest of that part of your system including pumps (the 007) & fittings. You would need some sort of anti-corrosion maintenance program for whatever part of your system is open - usually annual water testing & chemical treatment.

I don't know how much codes & regulations are impacting what you're doing, but I don't think there are very many running closed storage that are using an ASME certified storage tank setup.

One more note on your expansion - would be very good to get it as high as possible or as high as the highest point in that part of the system. And you should be able to run it closed. I had a 110 gallon LP tank for non-bladder expansion for my 660 gallons of storage. I ran it that way for 3 years, and it worked OK. But it was on the floor right beside my storage so would introduce some air over time, enough that I had to bleed one of my upstairs zones a couple times a season. I switched to a bladder tank this summer, but I would have kept the 110 gallon tank if I could have found a high place to put it. There is a corner in our master bedroom it would have fit, and I could have plumbed it to, but I didn't even bother bringing that suggestion to our table - no way that one would have flew.

And on something else above - the heat loss from keeping your LP boiler hot with wood all the time comes from heat going out the LP exhaust vent. Some can live with that setup if it greatly simplifies things for them - it would just come at the expense of having to burn an unknown amount of more wood.
 
WoodWacker said:
Where would I lose it? Within the condensing boiler?
Click to expand...

Yes, up the chimney of the condensing boiler. May not be huge amounts of heat, but could add up over time.
 
WoodWacker said:
Karl, Thanks, this is some good info I was looking for.

I'm going to be using a Viessman Vitodens 100. Currently I only have 1 tap on each of the top's of my tanks and the same on the bottom. 1 1/4" NPT. I didn't put this in my thread earlier but, I think I can run water from wood boiler to tanks and not to HX because my HX is approx 6' lower than the bottoms of my tanks. I don't think the LK810 will push hot water almost 15' lower than my tank tops. At least that is my theory, please tell me if I'm mistaken. It will recirc just tanks (I hope), unless a zone is called upon. Each of my branches for zones have circulators.

Onto the wood boiler circulator. I chose the 007 because upon a zone request, the 007 starts at full bore for 30 seconds, giving it enough volume to make it(40' 1 1/4 insulated pex) to heat the HX before a zone pump kicks on. Then it will tone back as DeltaT across HX is decreased. VS is variable speed I assume? Which pump do you recommend? I prefer the theory just as you say: "proper temp to the heating loop without over pumping and mixing the storage tanks." What are the inputs to vary the speed of the VS pump? As my temp drops, I want to utilize as much heat from tanks as possible, as most do. I want to be able to add the last drop of heat from my tanks, use the hx as a preheater for Vitodens, until I reach a minimum tank temp switch via Aquastat to control 007/VS circ. If that makes any sense. Haha. Once I learn my return temp from panel heaters, I can adjust my tank aquastat to just above that temp, in turn, should open, and not allow for anymore pumping via 007.

I'm interested in the VS. What brand spec sheets should I be looking at?

Thank you,
WW
Click to expand...
The Veissman is a high pressure drop boiler, and you will need to pump it primary/secondary. that will keep it from losing (minimal) heat up any flue.
I have used the Taco Bumblebee (HEC-2) successfully, but I would consider waiting till the kinks are worked out of the Taco Viridian line. they will be way better than the bumblebee. at least on paper. but they're brand new right now. I don't know what 007 you are looking at, but it must be the 007VS, which is kind of like the HEC-2.
 
I don't see where the bumblebee has zone request terminals? Is this set up only with a zone controller?
 
it gets powered just like any circulator. it runs speed 1-4. no end switch style heat call contacts.
 
When set to SP, and Setpoint is reached, then it just tones back to slowest speed?

upload_2015-10-26_15-29-15.png
 
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