Vedolux 37 Install

[maple1]

One more after looking at your pics again.

Where your primary loop supply comes out of the right tank, turns up with a street 90, then goes across via another 90 & then down - will make a very vulnerable spot for an airlock. I would put another airvent in there somewhere. Maybe swap out the second 90 for a T and put a vent in the top of the T? Or cut one into the middle of the horizontal section? Either way, I would for sure vent that topmost section at the very topmost part of it. I think.

 

[Carprofessor]

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....

So is this reverse return? The boiler charges both tanks simultaneously but the loop is supplied by one tank and the return is on another.

 

[Coal Reaper]

looks good but i agree with the lack of valves. suggest adding them anywhere that you have not yet plumbed.
vents at top of tanks is great.
i think the reason that expansion tanks are connected to the bottom of the air seperator is so that there is no chance of air bubbles rising into the expansion tanks and "living" under the diaphram? corect me of wrong, but thatts my understanding.
the way your storage tanks are plumbed in will prevent return water from the house going straight into the boiler. if i have a zone that i am trying to bring up several degrees there is a potential for water that hasnt dumped enough BTUs to be returned to the boiler and then see a 20 going through boiler possibly causing an overheat. i have not seen this yet but theoritcally it can happen. the bumblebee limits this i suppose.

 

[Coal Reaper]

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.

good point. i am going to take the handles off mine now. my son is almost 3 and i could easily see something happening there...

 

[Carprofessor]

looks good but i agree with the lack of valves. suggest adding them anywhere that you have not yet plumbed.
vents at top of tanks is great.
i think the reason that expansion tanks are connected to the bottom of the air seperator is so that there is no chance of air bubbles rising into the expansion tanks and "living" under the diaphram? corect me of wrong, but thatts my understanding.
the way your storage tanks are plumbed in will prevent return water from the house going straight into the boiler. if i have a zone that i am trying to bring up several degrees there is a potential for water that hasnt dumped enough BTUs to be returned to the boiler and then see a 20 going through boiler possibly causing an overheat. i have not seen this yet but theoritcally it can happen. the bumblebee limits this i suppose.

I was just looking at my setup and I could cut into the 1-1/4 line that is going out of the top of the right tank into the house and place an air separator there. I could then run a 1/2" copper line to my expansion. Is this a better design? Would this also address the concern Maple has about a potential air lock in that section of line?

My diagrams and picture don't show it, but there are many ball valves in the circuit. Understand that this is an existing system hooked up to a propane boiler. I am tapping into the loop with the wood boiler. Currently I have 4 ball valves installed on the wood side- one on the end of each 1-1/4 line leading to and from the storage tanks. I can isolate the tanks or isolate the boiler. At this point there are no parts on the tanks that might need periodic service. I will put a valve in to isolate the expansion tanks. If the loading pump needed service I would isolate the boiler and drain it. If I put the wye strainers in I would put valves in for them. Once in the house, I would put valves in to isolate the bumble bee and valves in where I tap into the current loop. Are there other places that you would suggest I put them?

 

[Coal Reaper]

i dont know that you NEED an air seperator since you have the vents at the top of the tanks. if you are going to run a propane tank for expansion like maple did then you are fine with current connection. if it were me running bladder type expansion i would run my 1/2" line from a point in the system that is higher than the expansion tanks themselves. this may or may not even make a difference but that is what i would do.
valves at the bottom of storage so you have the option of not completly draining the tank unless needed. like i said its not worth re-doing all the plumbing you have so far done. you got some luck if you do indeed have all the valves listed and by chance none of them ended up in your pictures!

 

[Clarkbug]

So is this reverse return? The boiler charges both tanks simultaneously but the loop is supplied by one tank and the return is on another.


View attachment 136772

Reverse return would be if you instead piped your tanks so that the pipe on the return goes from the right tank to the left tank, then makes a bend and goes back to the boiler. The idea is that you want water to "see" the same length of piping no matter what tank its going through, if that makes sense.

If you have an air separator in your primary system, as well as the vents, you should be good to go.

 

[Bob Rohr]

A Clarkbug mentioned reverse return, the piping paths need to be about the same, looks like this.

 

[Clarkbug]

Thanks Bob! Thats exactly what I was thinking. I know the elbows add length, but at least its picked up by either flow path.

 

[Carprofessor]

Reverse return would be if you instead piped your tanks so that the pipe on the return goes from the right tank to the left tank, then makes a bend and goes back to the boiler. The idea is that you want water to "see" the same length of piping no matter what tank its going through, if that makes sense.

If you have an air separator in your primary system, as well as the vents, you should be good to go.

Would the same thing be achieved by putting the reverse in the supply line (the top one)? The return line (bottom one) is pretty hard to access now.

 

[maple1]

Yes.

But if you need heat to the zones at the same time that you are starting to charge depleted storage, there may be a bit more of a delay before your zones see hot water - since the tank your zones would pull from is not the one that the boiler supply hits first.

But that all may be a wash & not amount to much difference. It also might be a wash changing what you have now. If Dean says you should be good with how you have it now, I would go with that. I like the idea of zones pulling from right above where your boiler feeds your storage though, as is now. It can be good at times being able to send hot water basically right to your zones from you boiler, say if you come home late & your house needs heat & your storage is depleted.

 

[Carprofessor]

The whole reverse return discussion is very interesting. The design I currently have is the same as the one Varmebaronen recommends as illustrated in this picture. (I trust posting this picture is ok... not a copyright issue?)




So why has Varmebaronen apparently not used reverse return? Am I correct that the reverse return design is intended to create the same flow through both tanks to ensure they heat at the same rate? Is it possible that they intended the tank with the house supply to heat first/faster?

Maple'sobservation;"there may be a bit more of a delay before your zones see hot water - since the tank your zones would pull from is not the one that the boiler supply hits first" - suggests that this might be so. Would the Varmebaronen design not cause the tank closest to the boiler to heat a little quicker, making hotter water available sooner? As the tanks are charged the other tank would always lag a little behind but would catch up at the end of the charge? I wonder if this design might also result in less turbulence in the tanks and therefore better stratification?

I going to stop now. I'm just guessing and you guys are going to think I'm talk out of my butt!

 

[maple1]

Nothing wrong with this discussion.

That picture shows about exactly the same setup as you have now. (Note also where the loads pull out of those [very pretty] tanks, at the top of the tank closest to the boiler).

That would be good enough for me - I think i would rely on them know what they're doing.

There are lots of little things to think about with this stuff. So much so that there are also lots of little things to second guess at & go around in circles about.

The only thing I would change would be to get an air vent in that top line like I mentioned.

(If the chance presented, I would also put valves on all the tanks like also shown in the pic before the tanks get filled - but don't think that's possible in your case. The main reason for me is my dug well & shallow well pump would not handle filling them back up again very easy very quick if I had to drain them for servicing.)

EDIT: Part of the equation in getting heat into all the tanks in the pic above is likely the orientation of the T's. The hot water comes to the close tank first, but it has to bend around the T to get into it. So the flow directed by the T orientations might be all there is to it. Simple T orientation is one of those little things to think about, that can play an impact on how much water goes where, everywhere in the system.

 

[Willman]

Maybe they are mono flow tees

 

[avc8130]

The whole reverse return discussion is very interesting. The design I currently have is the same as the one Varmebaronen recommends as illustrated in this picture. (I trust posting this picture is ok... not a copyright issue?)

View attachment 137024

Where are the supply and returns from the zones? That setup looks like it was a demo that could pretty much only charge "storage".

ac

 

[Clarkbug]

Reverse return is one of those "nice to have" things that is usually more important when you are piping up your heat emitters. It was the old-school way of avoiding a balancing valve or having to measure the flow. If the friction losses were the same in each loop, the flow would be the same, or at least close enough.

I probably shouldnt have mentioned it, but I also didnt realize how far you were piped up at the time.

As maple mentioned, there are a lot of ways to do things, and its just one of those little tweaks that can help. But since a tank is a really big volume, and there isnt a lot of friction losses in it anyway, we are really talking very minor differences. Its that last 1% of efficiency/stratification sorta thing. The way Varm has their tanks shown will work fine without any crazyness in the piping, since things will stratify on their own eventually through natural convection.

 

[maple1]

Where are the supply and returns from the zones? That setup looks like it was a demo that could pretty much only charge "storage".

ac

The zone supply is the stubby T looking thing in the top of the left tank. Return likely down low where can't see it. Or into the bottom right side of the right tank.

 

[Clarkbug]

The zone supply is the stubby T looking thing in the top of the left tank. Return likely down low where can't see it. Or into the bottom right side of the right tank.

Supply and return both got into that stubby T on the top, which is really a modulating three way valve. There is a shunt in the tank itself to pull hot from the top and cold from lower in the tank. The idea is that it also is equipped with an actuator that is driven based on the outdoor air temp to adjust the supply water temp.

 

[maple1]

That's right - forgot about that.

That total Varm system is very nice, with those sexy tanks. They weren't in the cards for me though, getting them here made used propane tanks found here even more appealing.

 

[alaskawild]

Always use an air separator or air scoop if you can in addition to your tank air vents. Way more efficient at getting the air out! And remember the 18" rule if you use an air scoop. Also if you keep your water flow at or above 4ft per sec the air tends to stay in suspension and move to the air separator. Just my two cents.

 

[Carprofessor]

Always use an air separator or air scoop if you can in addition to your tank air vents. Way more efficient at getting the air out! And remember the 18" rule if you use an air scoop. Also if you keep your water flow at or above 4ft per sec the air tends to stay in suspension and move to the air separator. Just my two cents.

What's the 18" rule? I 've got an air scoop on my existing propane boiler (see diagram in my first post). The V37 will be circulating through the same loop and I'm counting on that scoop to do the job. I'm using a Taco Bumble Bee as the circulating pump. It sets the water flow as required. (I think it increases flow as the water supply temp drops, minimizing heat loss in the storage tanks and limiting turbulence in the storage tanks).

 

[Carprofessor]

Expansion tanks went in yesterday. The are Amtrol Extrol SX110's. I haven't plumbed them yet but I will T them at the base of the top tank. Shut off valve there as well so that they can be isolated. As recommended by Dean, I will put a drain valve on the expansion tank side of the shut off so that I can release the water pressure and check the tank initial pressure. This will also allow me to remove any air that might accumulate in the beginning.

The darker wall in the picture is insulation. The storage tanks are behind them. I was using white Styrofoam but ran out and couldn't get any more used stuff. This is also a foam but it supposedly has almost twice the R value. The sheets are doubled up in the walls giving me 6 inches of insulation all around the tanks. I've just placed them loosely for now so that I can pull them out once the boiler fires up and check for any leaks. Eventually I will sheet the walls in with the corrugated tin that is on the other walls and ceiling.

 

[Carprofessor]

Today was chimney day. I hoped to have this done weeks ago but the roof flashing was backordered. In the attached pictures you can see the rough opening, the ceiling support and the finished chimney. Haven't attached up to the boiler yet. It's supposed to rain soon and I will check for leaks before closing up the ceiling (more tin!) and then move the boiler in place to connect.

 

[Carprofessor]

This is a picture of the inside of the boiler room. This has been more work than the boiler itself but is starting to come together. All the inside is lined with recycled tin roofing that has been painted (one coat) with galvanized metal primer. The walls have 3.5" of white Styrofoam in them and the ceiling is double (7"). There is a set of double doors at the end to get my wood supply in and out and also to move the lawn tractor etc. I put 2 sets of 4' lights in with "daylight" bulbs. The lighting is excellent. The boiler will move closer to the front of the picture once hooked up to the chimney, leaving room for about 5 cords of firewood. I'm hoping that lots for 1 winter. (Some suggest it is.)

 

[alaskawild]

What's the 18" rule? I 've got an air scoop on my existing propane boiler (see diagram in my first post). The V37 will be circulating through the same loop and I'm counting on that scoop to do the job. I'm using a Taco Bumble Bee are the circulating pump. It sets the water flow as required. (I think it increases flow as the water supply temp drops, minimizing heat loss in the storage tanks and limiting turbulence in the storage tanks).

Carprofessor...

I looked at your diagram just now. I really couldn't tell what you were using. I was referring to any cast iron air scoop like a Watts or Taco style. If someone is using this style they should allow 18" of unobstructed pipe before entering the scoop. If you could see inside a pipe any air traveling along in the water flow is mixed in that water column. On a horizontal run where an air scoop is installed the air will migrate to the top section of pipe but it takes at least 18" to effectively do this. The scoops are a really simple design. The air is literally scooped off the top of this column of water as it moves thru the air scoop. If a scoop is installed next to say an elbow the turbulence created by the elbow cause turbulence in that water column mixing the air bubbles and causing many bubbles to pass thru without being captured. Of course if you are using an air separator forget the 18" rule. They work almost anywhere!
As for velocity I was referring to, too little. This is rare! If flow is really low air will separate in the system in various places and just remain stuck there. It takes some velocity to keep air suspended in the water column so it will move to an air vent. Believe me this is rare. I can only remember two incidents of this in 35 years. Of course with high velocity you will know! It is a balancing act LOL
The Bumble Bee is a great pump and is setup to use delta-t for control. One thing misunderstood by some is that this pump does have a minimum speed that it will run at. It does not completely shut-off on it's own. Good luck! Great looking project