comments on 2 storage/boiler hook up scenaios

[Northwoodsman]

Guys,

Please review the attached schematics and let me know your opinions as to which on is the best and reasons why.

Also, please give me your 2 cents as to why a storage tank should be plummbed hot in top and cold out the bottom.

Thanks,

NWM

 

[taxidermist]

Mine is plumbed like # 2 drawing, I like to charge and draw off both tanks at the same time. TOP to BOTTOM = When water is heated it expands and becomes less dense therefor it rises to the top. (The reason hot water rises is because heating up the water gives each of its molecules more kinetic (or motion) energy. This energy causes the molecules to spread apart. When the molecules spread apart, the density of the water decreases (fewer molecules per unit of volume). Less density means that heated water is lighter than an equal volume of cold water. The lighter heated water thus rises to the top of the containter and the heavier colder sinks to the bottom)



I stoled that from the web.

Rob

 

[stee6043]

I am plumbed like your top diagram (tanks in series). I tend to believe the plumbing is a bit simpler and I don't have to worry about balancing the flow into each tank. Just my opinion, however...

 

[WoodNotOil]

If you do the tanks in series, make sure bring the hot water into the top of the first tank, tank 1 bottom to tank two top, and tank 2 bottom to boiler return. That makes each tank stratified. Hotest water is at the top of tank 1, then bottom of tank 1, top of tank 2, and coolest is bottom of tank 2. You will have hotter water available this way than if you allowed the tanks to simply mix.

The parrallel option is fine as well, just make sure hot is to top of each tank and cold is from bottom (that is how you have it in the picture).

 

[stee6043]

If you do the tanks in series, make sure bring the hot water into the top of the first tank, tank 1 bottom to tank two top, and tank 2 bottom to boiler return. That makes each tank stratified. Hotest water is at the top of tank 1, then bottom of tank 1, top of tank 2, and coolest is bottom of tank 2. You will have hotter water available this way than if you allowed the tanks to simply mix.

The parrallel option is fine as well, just make sure hot is to top of each tank and cold is from bottom (that is how you have it in the picture).

+1. I didn't pay that close attention to your actual routing of the pipes in your diagram. But Wood is right, it's critical you plumb the top and bottom of the tank properly...

 

[101x81]

If you do the tanks in series, make sure bring the hot water into the top of the first tank, tank 1 bottom to tank two top, and tank 2 bottom to boiler return. That makes each tank stratified. Hotest water is at the top of tank 1, then bottom of tank 1, top of tank 2, and coolest is bottom of tank 2. You will have hotter water available this way than if you allowed the tanks to simply mix.

The parrallel option is fine as well, just make sure hot is to top of each tank and cold is from bottom (that is how you have it in the picture).

+1. I didn't pay that close attention to your actual routing of the pipes in your diagram. But Wood is right, it's critical you plumb the top and bottom of the tank properly...

what will happen if it is plum the other way?

is pressurised storage will change the way it's work?

 

[Northwoodsman]

When plumbing like figure 2 has, how critical is is to get the pipes cut to the identical distances/circ pump speed dialed in so that we pick up the same amount of water out of each take at the same flow rates.

I'm assuming that as long as the pipes are centered with the tanks at the tee that +/- .50" in pipe length would still allow everything to work good.

Thanks,

NWM

 

[taxidermist]

When plumbing like figure 2 has, how critical is is to get the pipes cut to the identical distances/circ pump speed dialed in so that we pick up the same amount of water out of each take at the same flow rates.

I'm assuming that as long as the pipes are centered with the tanks at the tee that +/- .50" in pipe length would still allow everything to work good.

Thanks,

NWM

I got mine as close as I could and seems to work fine. When I get my sensors hooked up I will know more.

Rob

 

[leaddog]

I have four tanks and I plumbed mine both ways. I have two in series and then they are connected in parallel. I did it this way so I would get better stratification as I'm drawing hot from the top and I seem to get less mixing this way. I do have all four tanks vertical so that does make a difference. As was stated if you go series be sure and pipe top to bottem. That way you will be taking the hotest water from one tank and putting it into the other so the one tank will stay hotter then the other untill you fully charge.
leaddog

 

[WoodNotOil]

When plumbing like figure 2 has, how critical is is to get the pipes cut to the identical distances/circ pump speed dialed in so that we pick up the same amount of water out of each take at the same flow rates.

I'm assuming that as long as the pipes are centered with the tanks at the tee that +/- .50" in pipe length would still allow everything to work good.

Thanks,

NWM

All you really need is a shutoff valve on each tank that you can use to balance the flow by partially closing the one that is picking up more heat. It is likely to be pretty close so long as the pipe lengths are close...

 

[jimde]

How would you plumb 3 tanks in parrallel and keep the same distance if they are vertical and standing inline next to each other?

 

[DaveBP]

How would you plumb 3 tanks in parrallel and keep the same distance if they are vertical and standing inline next to each other?

It's not that the tanks have to be equidistant but that the total path from boiler through each tank and back to the boiler should be about equal length and same fittings. Page 4 of this pdf from Tarm shows one way of doing it. These are connected in parallel with different lengths of pipe going to each but the returns are adding up to the same length total for each tank.

http://www.woodboilers.com/userfiles/file/Solo Innova Plumbing(1).pdf

You may have to copy/paste this into your browser to get there.

 

[pybyr]

I am plumbed like your top diagram (tanks in series). I tend to believe the plumbing is a bit simpler and I don't have to worry about balancing the flow into each tank. Just my opinion, however...

IIRC, your 2 tanks are set up in a horizontal position, stacked one above the other- so I've assumed that your top tank is where the heat tends to accumulate/remain under conditions where it's not all at highest temperatures?

 

[stee6043]

I am plumbed like your top diagram (tanks in series). I tend to believe the plumbing is a bit simpler and I don't have to worry about balancing the flow into each tank. Just my opinion, however...

IIRC, your 2 tanks are set up in a horizontal position, stacked one above the other- so I've assumed that your top tank is where the heat tends to accumulate/remain under conditions where it's not all at highest temperatures?

It really depends on how I burn. But certainly during normal operation I draw the heat off the top of the top tank and return cool water to the bottom of the bottom tank. So once I start to get seperation the hottest water will be in the top tank last. Typically when I'm done with a daily burn I will have 170-175 top to bottom, both tanks. When it's time for another burn the next day I'll be flirting with 155-160 at the top of the top and usually 135-140 at the bottom of the bottom.