Vedolux 37 Install

[Carprofessor]

Thanks to everyone who provided advice to help me select a boiler. I have purchased a Varmebaronen Vedolux 37 and will install it with 2 500 gal. repurposed propane tanks. The boiler and the tank are installed in a lean-to style shed that is attached to the back of my attached garage. This is an ideal location because the current propane boiler is in the basement, on the other side of the wall from the wood boiler. There is plenty of room for firewood in the shed plus I can walk out of the house, through the garage and into the shed without going outside. Plan to do this in my slippers!

I'd like to share some of the progress I have made. I welcome all constructive comments and opinions, but understand that some things are done and not likely to get re-done unless there is a serious error. Thanks for reading.

Maybe a good place to start is to show you the plan that I am following. Dean at Smokeless Heat helped me develop the schematic below.

 

[Coal Reaper]

Very familiar...

 

[Carprofessor]

Before taking delivery of the 2 500 gallon propane tanks that will provide thermal storage I had to do a lot of prep work in the shed. The shed is 8 x 35 and is sitting on concrete posts. I have stored firewood in it for several years and over time the wall has moved out. I dug up the dirt floor and wrapped steel bands around each post. I welded threaded rod on the bands and attached them to a steel bar that was anchored to the garage foundation. Drawing down on the threaded rod straightened the wall out and it won't move again!

 

[Carprofessor]

I was told that positioning the thermal storage tanks vertically was preferred due to improved stratification properties. Also, positioning them horizontally was a waste of valuable space in the shed. Problem... the tanks are 10' long and the shed is 8' tall. I dug a pit and poured a 4x8 concrete pad 6" thick to provide the needed overhead clearance.

 

[Carprofessor]

I needed to insulate the shed to prevent freezing if the boiler is off for any prolonged time and to keep the storage water from cooling as much as possible. I priced spray foam but it was quite expensive. I found used sheets of Styrofoam (4x8x3") and used that. I know it doesn't have the same R value as spray foam but it was so cheap I put 6" in the ceiling and around the storage tanks. Worked out to almost 10x cheaper. Looked odd driving down the highway though.

 

[Carprofessor]

This was the day the storage tanks were delivered. Ted Kestor supplied and welded the ports on them. You can see were he cut a large square section out to get inside to clean them. He also rinses them inside with muriatic acid. Ted normally welds legs on them but my concern with height as well as the overall footprint led me to having him weld car tire rims on the bottom. This resulted in only a 3" increase in height and no increase in the foot print. I saved a bit of money by skipping the paint job. Your not going to see them once they are installed.

The guys in the picture are still my friends, so the install must have gone well!. We used the chain hoist to lift them off the trailer. I threw a bunch of 2x6's down and moved them using two large oak rollers. This worked very well. Once placed at the end of the shed they had to be stood upright on the concrete pad. With the 4 of us plus Ted and his son there was no effort to stand them up.

 

[Carprofessor]

This is where I am today. The storage tanks are in place and have been plumbed part way with 1-1/4 galvanized pipe. The pipe terminates on the house side and the boiler side with ball valves. I will make the connections to the boiler and the primary loop with copper I filled the tanks and placed them under 40 psi for a few days. No leaks. It looks like I will need 2 SX110 expansion tanks that will be stacked in the far end. I placed 65 24x24 patio blocks down for a floor. The chimney connection on the boiler has been modified from a horizontal pipe connection to a vertical one. I bought 3 lengths of brand new insulated chimney in a yard sale for a great price. The roof flashing, ceiling support and rain cap are on order and should be here this week. I picked up enough used tin roofing to line the inside of shed.

 

[arngnick]

Awesome pictures!! Looks like a very nice setup...its a lot of work but I think you will be happy not too much I see that I would do different. I have been burning all summer for domestic water and love it!

 

[maple1]

You are going to love the heat that thing will pump out.

And, after the 'new car' thing wears off in a year or so, really appreciate how easy it is to clean.

Curious on the galvanized though - I always had the impression it was a no no for boiler piping? But I'm no pro.

 

[Carprofessor]

You are going to love the heat that thing will pump out.

And, after the 'new car' thing wears off in a year or so, really appreciate how easy it is to clean.

Curious on the galvanized though - I always had the impression it was a no no for boiler piping? But I'm no pro.

Thanks for your comments. I hadn't heard anything about a disadvantage with galvanized. I'm no expert either, and I thought spending more money on galvanized was better than black iron. I found the thread below that discusses this.
https://www.hearth.com/talk/threads/black-iron-and-galvanized-pipe.13057/

It seems that black iron would have been fine. Galvanized and corrosion can be a problem when used with glycol (I'm not) or when mixed metals are used. I used all galvanized. There can be a corrosion problem where I switch to copper, but the thread says place a cast or bronze union in the line before the switch. I have bronze ball valves at the end of each galvanized run before copper starts, so maybe I'm ok??

 

[arngnick]

Just looking at your layout some more. Do you have overheat protection? With the boiler being nearly the highest component in the system you will have limited thermo siphon going on.

 

[Clarkbug]

I was going to ask the same question as arngnick, make sure you have an overheat/dump loop.

Also, my varm is rated to 1.5 bar, not 30 psi, so take that into account with your expansion tank sizing. Are you piping the tanks reverse-return to make sure they both fill? Or adding a balancing valve in there to help divert the flow?

 

[Carprofessor]

Just looking at your layout some more. Do you have overheat protection? With the boiler being nearly the highest component in the system you will have limited thermo siphon going on.

A very good point. There is a 3-1/2' rise from the outlet port of the boiler to the top of the storage tank and a 3-1/2' drop from the inlet port on the boiler to the bottom of the storage tank. I don't know what the minimum requirements would be to create thermo syphoning. Is there doubt this will occur?

 

[maple1]

Just to follow up on a couple more things mentioned above, for expansion I have one 110 gallon propane tank (no diapraghm), to handle my 660 gallons. It is lots, I only get a rise of maybe 4psi from cold to hot (from 8 or so to 12 or so?). You might be able to do something similar using ordinary small propane tanks? Looks like you might have a good place to put them - up high back in the corner in your lean-too above the tanks. Mine is on the floor beside them and seems to be working out Ok after two winters - although I would really like to have my expansion up high if I had a place to put it. Just that that would be a LOT cheaper than diapraghm tanks - if you could find a couple 110 gallon tanks or similar. Some on here are also using ordinary hot water heater tanks for expansion. Just make sure you have enough (more that enough is always better) - and if you come up with an idea you think might work run it past Dean. Study the part of your manual that talks about expansion - it has ideas in it for an open expansion tank up high, for an open system. The closed scenario doesn't specify diapraghm - so I think maybe a closed non-diapraghm tank up high would be OK - and better than what I've been running,

And as clarkbug mentioned, the blow off valve that comes with the boiler is rated at somewhere around 20psi I think. Lower than 'typical' for pressurized boilers. Use it, and keep your hot high pressure below say around 15 psi. Should still work good since that would be at close to the high spot in your system, and pressure will be higher down lower.

And yes, certainly overheat protection is needed. Looks like up high in your lean-too would be a good spot for that too if you don't already have something planned. Just plumb in a few pieces of hot water baseboard radiation up there running through a normally open zone valve, controlled by a break-on-rise aquastat - the stat doesn't have to be in a well, a Johnson A-419 would work pretty good and it has an external temp sensor you could surface mount to an outlet at the top of your boiler.

 

[maple1]

A very good point. There is a 3-1/2' rise from the outlet port of the boiler to the top of the storage tank and a 3-1/2' drop from the inlet port on the boiler to the bottom of the storage tank. I don't know what the minimum requirements would be to create thermo syphoning. Is there doubt this will occur?

Guess you posted while I was typing.

Dean can answer that.

But redundancy is a very good thing when it comes to boilers.

I later also added a 2200va UPS to my loading unit power line for extra peace of mind in a power outage - so I'm covered a few ways.

 

[Carprofessor]

I was going to ask the same question as arngnick, make sure you have an overheat/dump loop.

Also, my varm is rated to 1.5 bar, not 30 psi, so take that into account with your expansion tank sizing. Are you piping the tanks reverse-return to make sure they both fill? Or adding a balancing valve in there to help divert the flow?

I'm putting in a 22.5 psi release valve. Is that 1.5 bar? I don't know what the calculation for expansion tanks is. I'm told that the V37 is often installed using 2 SX110 expansion tanks when 1000 gal of storage is used. Can someone add more about this?

Can you explain what reverse return is? The plan is to stack the 2 expansion tanks beside the storage tanks. They would be on the same floor as the boiler and once stacked would be close to even with the top of the storage tanks. I believe the connections are on the bottom of the expansion tanks. I have a 1/2" copper line running from the expansion tank connections to a T in the 1-1/4" line between the storage tank and the return on the boiler.

 

[Coal Reaper]

looking good!
i never ended up incorporating a dump zone or the like but i used skinny 500's, 13' tall IIRC. i have not been able to trip the overheat protection on boiler (fan kill) even during a power failure. you will learn how much wood it tales to bring storage to full charge. i find myself looking at the system pressure mostly. search for 'weighing wood' for some insight in how to dial down your loads to get full charge without overheating.
do you have temp gages on your storage tanks? i got an x-300 unit from controlbyweb and have been very happy with it even though i still dont use it to its fullest capabilities. https://www.hearth.com/talk/threads/controlbyweb-x300-temp-monitor.116801/
you probably dont need wye strainers since your tanks were cleaned very well but if you do, put valves on either side so you dont have to depressurize the whole system to clean them. for this reason mine have yet to be checked...
the only other thing i can add/re-iterate is that these really need dry wood. smokes above 25%MC and at 20-25% you dont get the heat you would from <20% wood. i split small at 20" lengths so i can really pack it tight when i need to.

 

[Carprofessor]

Just to follow up on a couple more things mentioned above, for expansion I have one 110 gallon propane tank (no diaphragm), to handle my 660 gallons.

Is there not a concern with having the oxygen present in the system without a diaphragm? There is a very informative thread on this site about using non-diaphragm expansion tanks. One person said that once a year he drains any water from the tanks and tops up the pre-charge and that's it. Some else says that if you are going without a diaphragm you need to run boiler chemicals and that's expensive. Someone else suggested that pre-charging with nitrogen might be a solution.

If this can be addressed I would certainly like to avoid the cost of expansion tanks at about $450 each.

I heard of adding the UPS to the loading pump. We get power interruptions far to often here so I think its a good idea. How long will this run your loading pump? Am I correct that a typical burn in the V37 is about 3 hours? As long as it would run the pump that long there should be no concern (unless it was the loading pump that failed, not a power outage!)

 

[Coal Reaper]

give us some more pics of your plumbing connections.
connection to bladder type expansion tanks should come of the bottom of an air separator that ideally is located near the top of storage tanks. idk about maples setup but it sure would be nice to save $1k.
1.5bar=21.75psi. my system swings from 12 to 21psi if i fire storage close to 200*F.
correct on typical burn +/- a half hour depending on density of wood.

 

[Carprofessor]

looking good!
i never ended up incorporating a dump zone or the like but i used skinny 500's, 13' tall IIRC. i have not been able to trip the overheat protection on boiler (fan kill) even during a power failure. you will learn how much wood it tales to bring storage to full charge. i find myself looking at the system pressure mostly. search for 'weighing wood' for some insight in how to dial down your loads to get full charge without overheating.
do you have temp gages on your storage tanks? i got an x-300 unit from controlbyweb and have been very happy with it even though i still dont use it to its fullest capabilities. https://www.hearth.com/talk/threads/controlbyweb-x300-temp-monitor.116801/
you probably dont need wye strainers since your tanks were cleaned very well but if you do, put valves on either side so you dont have to depressurize the whole system to clean them. for this reason mine have yet to be checked...
the only other thing i can add/re-iterate is that these really need dry wood. smokes above 25%MC and at 20-25% you dont get the heat you would from <20% wood. i split small at 20" lengths so i can really pack it tight when i need to.

The pic's you posted of your tanks looks great. The height must work well.

I read your post on the x-300. I was looking at digital water temperature gauges used in cars. I thought I could epoxy them on the outside of the tank, top and bottom on each one. What would you see as the advantage of the x-300? Are the temp sensors externally mounted or do you have to put wells in?

I have filled and drained my storage tanks a couple of times. There is a rust stain on the ground afterwards, but no solids. Once the oxygen has been eliminated in the system there should be no further corrosion. Right?

I get my firewood delivered in log length and then cut and split it. I get mostly ash. I have 8 cords (cut 2 years ago) stacked outside now and will move 4 cords into the wood shed this fall. I'll get another load this winter. I got a moisture meter last spring but took it back because the readout was too small. Any recommendations?

Splitting the wood a bit small makes sense given the small firebox door and packing tightly, but I've read that larger pieces of wood create better results. Any thoughts on that?

How much temperature rise do you get in one burn? How many burns to fully heat the storage tanks?

 

[maple1]

Is there not a concern with having the oxygen present in the system without a diaphragm? There is a very informative thread on this site about using non-diaphragm expansion tanks. One person said that once a year he drains any water from the tanks and tops up the pre-charge and that's it. Some else says that if you are going without a diaphragm you need to run boiler chemicals and that's expensive. Someone else suggested that pre-charging with nitrogen might be a solution.

If this can be addressed I would certainly like to avoid the cost of expansion tanks at about $450 each.

I heard of adding the UPS to the loading pump. We get power interruptions far to often here so I think its a good idea. How long will this run your loading pump? Am I correct that a typical burn in the V37 is about 3 hours? As long as it would run the pump that long there should be no concern (unless it was the loading pump that failed, not a power outage!)

Crap, just deleted a bunch of typing. I'll try again.

I had a concern yes, and did it realizing I may end up getting some diaphragm tanks anyway. I couldn't pass up the chance to try out a $70 solution rather than one of over $1k. After 2 years I will not be changing it for this winter. Last summer I did not burn, and before I started re-charging the tanks in the fall I added some air & water because I thought my PSI was too low. But I ended up letting some back out before things got fully up to temp. So I don't think I had to do that - I think I just didn't read my guage close enough. And everything was at 65° or so. This summer I am charging to 180 or so, and a week later when I re-charge, temps are down to 95/115 or so. Pressures still seem good. I would be happier if my expansion was up high, and am still figuring how I could possibly do that (no luck yet that doesn't involve a tank in the master bedroom - which won't happen). I have re-read my manual a few times, and what it seems to show for pressurized expansion is more or less what I've got. It doesn't spec a bladder - although it is pretty light on details in places. So maybe it intended to. No chemicals or nitrogen here, or no draining etc, and I haven't topped anything up since last falls episode. Just haven't touched it at all. But if you really want to be more sure, ask Dean. Based on my 2 years, I would do what I did again, but would get my expansion up high - but would also certainly listen to what he had to say about it.

On the UPS, I found a 2200 va one on kijiji here at a good price. I don't know how long it will go, but it's more than 4 hours. From the specs it should go something like 12, but I haven't tested that out. I don't have a fan to run though - just the circ pump. Which is the main thing. One thing I didn't know at the time but found out afterwards, is that larger UPS's like this one have a cooling fan inside that runs all the time when it's plugged in. Which I don't like. So I keep mine unplugged most of the time - I will plug it in & plug my loading unit into it if I am heading out while there's a fire burning, or if the weather sounds like there might be an outage while burning. I time my burns so that the fire is pretty well out when I'm heading to bed, so I don't worry about it overnight either.

 

[Coal Reaper]

The pic's you posted of your tanks looks great. The height must work well.

I read your post on the x-300. I was looking at digital water temperature gauges used in cars. I thought I could epoxy them on the outside of the tank, top and bottom on each one. What would you see as the advantage of the x-300? Are the temp sensors externally mounted or do you have to put wells in?

I have filled and drained my storage tanks a couple of times. There is a rust stain on the ground afterwards, but no solids. Once the oxygen has been eliminated in the system there should be no further corrosion. Right?

I get my firewood delivered in log length and then cut and split it. I get mostly ash. I have 8 cords (cut 2 years ago) stacked outside now and will move 4 cords into the wood shed this fall. I'll get another load this winter. I got a moisture meter last spring but took it back because the readout was too small. Any recommendations?

Splitting the wood a bit small makes sense given the small firebox door and packing tightly, but I've read that larger pieces of wood create better results. Any thoughts on that?

How much temperature rise do you get in one burn? How many burns to fully heat the storage tanks?

i would do at least one more in the middle as well. if you are running the tanks in parallel then there is no need to put sensors on both tanks. no wells, i taped the sensors on the outside and then covered in spray foam. i tihnk i paid $300 for the x-300 and 7 sensors. right now i have cat-5 running to a dedicated laptop in the house so i can read the temps inside rather than going out to the barn. when i finally coordinate with a computer geek friend, i will have it hooked up such that i can read that screen on ANY internet capable computer or smart phone. also, it has three relays that can be controlled manually, timed, or temperature. my idea is to have it shut off the vedolux fan when storage hits 200*, allow oil boiler to fire when storage supply falls below 130* and a block heater for my truck, . you can also have it send you emails when pre-defined temps are hit. quite more than you really need, but a lot of capability for the money i thought. no more questioning whether or not i need to fire when i get home and i can really dial in how much wood to load in order to fully charge. might not be a big deal for you since you are attached or close to house. for me it would be less than ideal in inclement weather to trudge the 150' to the barn everytime i just wanted to check on things.
i went through 6 cords last winter. 2500sqft., 2x6 construction, lots of windows, on top of mountain. cant have too much wood in the bank, you will always get to it. good on yah for getting it inside barn. i will be moving mine in next month. idk what MM i have. you learn to feel what a dry piece of wood is.
the woodgun guys are the only ones that preffer larger splits that i have seen. i dont get any huffing unless i throw in a heap of dry splitter dribblings.
in my experience, one load of dense wood (BL, oak, black birch) yields alomst 1/2 million BTUs to storage with no load from house. so one load will charge if tank average is 140 ZZZhah, just found that button!). i need to burn three loads per day if temp are below 10 at night or 15 with a wind.

 

[Carprofessor]

give us some more pics of your plumbing connections.
connection to bladder type expansion tanks should come of the bottom of an air separator that ideally is located near the top of storage tanks. idk about maples setup but it sure would be nice to save $1k.
1.5bar=21.75psi. my system swings from 12 to 21psi if i fire storage close to 200*F.
correct on typical burn +/- a half hour depending on density of wood.

I have updated my diagram to more correctly display what I have done. The main change is the placement of the expansion tanks. I am getting a bit of conflicting information on this. The dealer's original sketch showed the supply ports from the tanks to the boiler with a note saying "place a low as possible on the tanks". He also showed the expansion tanks tee'd off at this same point and mounted even lower than the storage tanks. The only piece of plumbing on the line to the expansion tanks was a shut off valve. The storage tanks have an air vent at the top, but I don't think that qualifies as an air separator. The only air separator is the one in the primary loop that was originally installed with the propane boiler. My understanding is that the separator can be mounted anywhere in the system that water will flow past.

There is not a supply port to the primary loop on the left hand tank. There is only one on the right hand tank. I questioned this at the time but was told that the water will stratify better this way. Return water to the boiler comes into the left hand tank only and supply water to the primary loop comes from the right hand tank only. The common connections to both tanks created by the boiler connections is supposed to equalize the temperature in both tanks with the minimum of disturbance.

Any thoughts on what might not be right?


This is a shot of the T where the 1/2" line to the expansion tanks is connected. This is at the lowest point on the storage tank.



This is a shot of the top of the tanks. The right hand tank supplies water to the primary loop in the house. The line below, connected to both tanks, is the supply water from the boiler.




These are the air vents mounted in the top of each tank.


The top port in this shot is the return from the house into the left hand tank only. The bottom port is the return line to the boiler and s connected to both tanks. This is the line that the T for the expansion tank is in.

 

[Clarkbug]

I'm putting in a 22.5 psi release valve. Is that 1.5 bar? I don't know what the calculation for expansion tanks is. I'm told that the V37 is often installed using 2 SX110 expansion tanks when 1000 gal of storage is used. Can someone add more about this?

Can you explain what reverse return is? The plan is to stack the 2 expansion tanks beside the storage tanks. They would be on the same floor as the boiler and once stacked would be close to even with the top of the storage tanks. I believe the connections are on the bottom of the expansion tanks. I have a 1/2" copper line running from the expansion tank connections to a T in the 1-1/4" line between the storage tank and the return on the boiler.

As CoalReaper mentioned, 22.5 is pretty close to 1.5 bar. You got it!

As far as the tie-in point, ideally the expansion will be tied in where there is a "point of no pressure change". Essentially, thats the point in the system where you wont have a pressure spike based on a pump coming on or off. That gets tricky when dealing with storage and loading pumps sometimes. For what its worth, I have mine tied in in the same spot that you do. Works fine so far!

Just make sure to take the handle off of the shut-off valve to the expansion tanks. You dont want to have it accidentally closed when the system is in operation. But you do want it there in case you ever need to service the tanks.

Reverse-Return is actually a method of piping your storage tanks, not your expansion tanks. The idea is that you would pipe in the supply one way, and then reverse the order on the return from the tanks. That way water from each tank has to flow through the same equivalent length of piping no matter which way it goes, so the friction losses equal out.

You will get some great thermo syphon with the elevation changes you have in the tanks currently. Nice work! I dont know if you can eliminate the dump zone entirely, but you might be able to get away with it.... But I sure would sweat bullets the first time the power went out until I was sure....

 

[maple1]

That's pretty well how I have my expansion tank T'd in - except comparing to yours would have T'd in to the left bottom T, from the left. I don't think it really matters where you actually place the expansion tanks especially with diaphragms - they could likely go anywhere - even somewhere on the other side of your house if you wanted.

The 'reverse return' thing just means that the return would exit your storage opposite the point where supply enters. In this case, with supply going on top right, the return would exit to boiler at bottom left, or the opposite side of where it does. Which in theory would set up more of a cross-flow through both thanks and maybe utilize them more fully. But others have them plumbed as you did and post good results - and I think that is also the way the factory Varm tanks are plumbed in. Although my memory of the literature is kind of fuzzy. With vertical tanks and the natural stratification effect of hotter water being lighter, it likely equalizes itself pretty good during the course of a charging.

Think your vents are good too - top of storage makes a very good air trap.

I must say though - I would have (and did) put in a lot of ball valves for isolating things. I might have gone overkill on that, but I've got them at each tank fitting, and almost on each side of every T. Have you pressure tested the piping yet too?

EDIT: Typed too slow again I see...