hydro separators?

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flyingcow

Minister of Fire
Jun 4, 2008
2,563
northern-half of maine
Will be having my Innova w 800 gals of storage installed soon. I think the installer plans on using the layout Tarm provides. In general terms i understand it, but what to heck is a hydro seperator, i don't even know if I'm using/spelling the term correctly. Will this be an advantage to what end? Any thoughts would be appreciated, but in laymans terms. Or terms a dumb truck driver could understand. :)
 
Beats me ... let us know when you find out.
 

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I am far from an expert on this sort of thing, so this is only a guess - it looks like this is similar to a primary/secondary setup. It looks like the left half is like a primary loop and the right half is like a secondary loop. The separator looks like closely spaced Ts - they even mention the low pressure drop from top to bottom.
 
This is exactly what I want to put into my system over the summer to go from a series to a P/S like setup. Boilers go on one side of it and the zone loops on the other. It is a very good thing and much better than the series hookup Tarm used to push in their manuals. I would love to see the piping scheme you will be working from.
 
it removes air from a closed system. i have 2 on my set up. one on the wood side and the other on the propane side.
 
henfruit said:
it removes air from a closed system. i have 2 on my set up. one on the wood side and the other on the propane side.

No, that is an air separator. You would only need one hydro separator as it acts as the primary loop in P/S type piping scheme. That is the advantage of using one. Eliminates the need for closely space tees and a primary loop pump.
 

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Has anyone come up with a good hydro separator schematic with storage? Im not sure how it would be best to do that? Or maybe set things up with a big buffer tank hydro separator. It couldn't be to big or it would leave a lot of lag between building a fire and getting heat when the tank is cold but it could work out. Something like a 120gal propane tank with 4 tappings put on the sides.
 
iwas not aware that it did more. why would they have installed two/ one at the back of the wood boiler.(greenwood) that has a pump before it and one after it that pump tp a 40 plate hx. then one on the propane side that has 3 pumps from the con denseing boiler. thanks for the help merry christmas. light snow here today in nh.
 
i do have two ,maybe because the boiler was moved from the cellar to an out building???? but the boiler was always on the inlet side of the hx.
 
A properly piped tank would be an excellent hydro separator. The key is large size piping on the tank connections, and keep them across from one another.

It nice to have a screen inside the top flow path to aid in air removal and allows sediment to fall out, but not necessary for the hydraulics to work.

The 150- 250 gallon LP tanks, vertical mount would be one thought for a combo buffer, seperator, and air and dirt removal multi purpose device. We have tried for years to get tank manufacturers to build these. HTP makes a small 20 gallon. The Boiler Buddy is a larger maybe 80 gallon version.

hr
 

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WoodNotOil said:
You most likely have two air separators (I do in my system). You would only need one hydro separator in a system. Read the links above to find out more of what they do.

There are two in the system in question because there are two boilers, which each separately have need of separation. The primary hydro-separator links the boilers to the zones, as typical. The additional unit is used at the wood boiler, to allow it to quickly heat up, providing thermal shock protection.

henfruit said:
i do have two ,maybe because the boiler was moved from the cellar to an out building???? but the boiler was always on the inlet side of the hx.

Exactly. The hydro-separator allows good flow in the boiler, instead of having to flow all the water in the boiler and underground piping and heat exchanger through the system, all the time. A simple closely-spaced-tees setup would do the same thing, but would not provide the air removal.

Joe
 
flyingcow said:
Will be having my Innova w 800 gals of storage installed soon. I think the installer plans on using the layout Tarm provides. In general terms i understand it, but what to heck is a hydro seperator, i don't even know if I'm using/spelling the term correctly. Will this be an advantage to what end? Any thoughts would be appreciated, but in laymans terms. Or terms a dumb truck driver could understand. :)

I hydraulic separation uncouples flow in the two sides of the system. This allows different pumps to run at different times and at different flow rates, without interfering with each other.

In the case of the Tarm installation, the boiler pumps a lot more heat than the house uses (presuming it's sized right, anyway), because it needs to be able to supply the house and charge the storage at the same time. The house zones don't need anywhere near as much flow. So the hydraulic separation allows the house zones to run a different flow rate than the boiler/storage system.

Hydraulic separation can be as simple as installing a pair of closely-spaced tees in the loop - if they are within a few pipe diameters, the flow is such that there is negligible influence between the two sides. That is what the Tarm diagram shows (at least, the one I have here shows that). The hydro-separator uses a small chamber to achieve the same thing, and most include air (and often dirt) removal, in one convenient package.

Personally, I use them on pretty much any installation. They're convenient, compact, and effective, without costing much more than doing the same thing with a dozen separate pieces of pipe, fittings, etc.

Joe
 
Along this same thread theme:

Joe, have you used the Caleffi Hydrolink unit?

Am I correct to think they are a hydraulic seperator and manifold put together. Does it do more than that?

How do you like them for the price? I have no idea what their price is.
 
Thanks Brownian. I'll look over Tarms layout, I had before, but some of the stuff is greek to me. My installer is on top of this stuff, but won't see him for a couple of weeks. Just starting to read the 78 page manual that came with the Innova.
 
DaveBP said:
Along this same thread theme:

Joe, have you used the Caleffi Hydrolink unit?

Am I correct to think they are a hydraulic seperator and manifold put together. Does it do more than that?

How do you like them for the price? I have no idea what their price is.

The hydrolink is, indeed, a separator and manifold put together. And it only does that (it doesn't have an air separator - just a vent). It also doesn’t work with zone valves. So it has limited usefulness, and I haven’t had a use for them. I don’t know the pricing, either, but Caleffi products are generally on the high end of price (but also quality, so I consider them a good value). I make pretty extensive use of their products in my business, as a result…

Joe
 
Can you have too much thermal storage? I was looking into a hydro separator tank (boiler buddy) as a way to increase my oil boiler firing time, with the long-range intent of taping a pressurized owb to it as well. I don't know if this is feasible, or even if the two systems are compatible pressure/volume wise.
 
btuser said:
Can you have too much thermal storage? I was looking into a hydro separator tank (boiler buddy) as a way to increase my oil boiler firing time, with the long-range intent of taping a pressurized owb to it as well. I don't know if this is feasible, or even if the two systems are compatible pressure/volume wise.

Yes and no... Thermal storage is essentially a compromise to balance the need to run solid fuel boilers hot and hard for an extended period in order to get a clean and efficient burn, plus the fact that you can't turn a wood fire on and off, and the fact that your house isn't going to need all the heat produced by that burn at one time... Because ALL tanks loose heat over time, and every time you do a heat transfer you loose a certain amount of energy, you are much better off storing your heat as fuel than as hot water. Thus the idea is that you should size the storage to match the output of the boiler, so that you aren't storing more than 1-2 firing cycles worth of heat. Some people use more than this as a way of "time shifting" their burning schedule to be more convenient, but this costs some level of efficiency...

Because fossil boilers can cycle on and off with minimal efficiency loss, and no time lag to speak of they don't gain a lot from storage, except in the limited case you mention of the "boiler buddy" that can store just a few minutes worth of hot water in order to increase the cycle time of low-mass boilers.

Standard OWB's are not pressurized, one interfaces them with a conventional system using a heat exchanger, or alternatively (and a solution we like because it's cleaner and more efficient) one can put a gassification wood boiler in an outbuilding, with storage either in the outbuilding or the house (each has advantages and disadvantages) However the standard recomendation is that one should tie the two systems together in such a way that one does NOT heat the storage with fossil fuels... By the same token, it is considered best if one can avoid heating the fossil system itself with the wood boiler... I think of it as having three "black boxes" - a house load, which needs hot water pumped into it, coupled to a "wood box" and a "fossil box" each of which make heat that can be fed to the "house box" but that should not feed heat to each other.

Bottom line is that a boiler buddy might be appropriate for your current fossil-fuel heating system, but I wouldn't figure on it having a lot of influence on your future wood burning plans. The only thing I would add to the existing system for "future proofing" is an extra tee in the supply and return lines where the house load connects to the current heating system, with a shutoff valve and cap on the unused branch. This gives you the tie in points for when you hook up the wood in the future.

Gooserider
 
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