Installing a Sorbox LI

TahoeJohn

I'm a homeowner in the process of converting my hydronic system from glycol to one based more on the VDI2035 principle of water management. Part of that will be to add an Elysator SorbOx LI anode/filter to my system.

I'll be installing it onto the main supply line between the boilers and the pumps, shown here with the red line:



My question is whether to add a bypass valve:



Or simply re-route the line through the SorbOx:



On one hand, I suppose the answer might be "why not, you're in there, it's just $50 and a couple tees extra." On the other hand, I'd like to understand if it's necessary, i.e. has anyone with a SorbOx ever had to actually bypass their filter?

That supply line is 1.5" copper, and the SorbOx has 1" fittings, but I'm still assuming that it can handle the full flow with all 4 pumps running, i.e. there's not a need to keep that bypass valve partially open. Purely an assumption, however.

Thanks!

EdTheHeaterMan

What size is the boiler? or better yet, what is the NET I=B=R rating (AHRI NET on new equipment). Here is the reason:
That is a "Rule of Thumb" for residential heating system design from this booklet
https://www.xylem.com/siteassets/brand/bell-amp-gossett/resources/technical-brochure/fh-z100b-bg-zoning-made-easy-2.pdf.

You may find that reducing from 1.5" copper which can handle 22 GPM or 220,000 BTUh (which is on another table in that booklet) to 1" copper that can only handle 8 GPM or 80,000 BTUh might cause a reduction of the amount of heat your system's radiators or other heat emitters will get from that boiler. The saying: You can't fit 10 Lbs. of potatoes in a 5 pound sack, comes to mind

TahoeJohn

EdTheHeaterMan said:

What size is the boiler?

Two boilers, in parallel, each rated at 100,000 BTU.

You may find that reducing from 1.5" copper which can handle 22 GPM or 220,000 BTUh (which is on another table in that booklet) to 1" copper that can only handle 8 GPM or 80,000 BTUh might cause a reduction of the amount of heat your system's radiators or other heat emitters will get from that boiler. The saying: You can't fit 10 Lbs. of potatoes in a 5 pound sack, comes to mind

Great point. Does this mean that I should install that bypass valve and keep it slightly open to allow part of the flow to go straight through while the other part of the flow gets filtered in the SorbOx??

TahoeJohn

On another thread, Roger_at_Sorbox mentions this, FWIW:

Since SorbOx has a very low pressure drop, it’s no problem to install it on systems with piping up to 1 ½”.

hot_rod

You have multiple Polaris tanks piped together for these 4 zones? Or is there more connected to those heaters?
Why the stainless steel circs, is it non barrier tube?

I suspect they pump 8 gpm, maybe a bit more. I see one flowmeter reading, what gpm? What is the total gpm when all 4 run?

EdTheHeaterMan

TahoeJohn said:

EdTheHeaterMan said:

What size is the boiler?

Two boilers, in parallel, each rated at 100,000 BTU...

...Great point. Does this mean that I should install that bypass valve and keep it slightly open to allow part of the flow to go straight through while the other part of the flow gets filtered in the SorbOx??

I would use a full 1.5" bypass with a globe valve. Globe valves are better for throttling than a ball valve.

hot_rod

Are you going to run the DI cartridge in it? That adds some flow restriction.

Looks like 13 gpm is what they show on the spec. So without knowing your actual flow rate we are all WAGing

The manual shows piping options. As a bypass filter you reduce the effectiveness somewhat, adding time for it to clean or DI the entire fluid volume system.

Certainly whatever you do is better than what you have now

EdTheHeaterMan

TahoeJohn said:

EdTheHeaterMan said:

What size is the boiler?

Two boilers, in parallel, each rated at 100,000 BTU.

100,000 BTU each? Is that rating the input? is that rating the output DOE? is that rating the NET? (NET on old boilers is I=B=R Net, AHRI Net on new boilers). That will help in determining the GPM of each boiler.

The next thing is, once we know the NET rating and determine the most GPM you can expect, then we can determine if you are actually using the most GPM or if you are using something less than the most.

Just because a pipe can carry 20 or 30 gallons per minute does no mean it IS carrying that much. You can put 5 pounds of potatos in a 10 pound sack.

hot_rod

Those are just tank type condensing water heaters, notice the T&P valves really no flow required to run them. What we need is the system design gpm, what actually will flow across the "box"?

Is this a combined heat and DHW system, still wondering why the bronze and stainless circs? But hydronic expansion tanks.

TahoeJohn

hot_rod said:

You have multiple Polaris tanks piped together for these 4 zones? Or is there more connected to those heaters?
Why the stainless steel circs, is it non barrier tube?

I suspect they pump 8 gpm, maybe a bit more. I see one flowmeter reading, what gpm? What is the total gpm when all 4 run?

Thank you for your help here, hot_rod.

There are 2 Polaris tanks piped together for these 4 zones. No other heat sources or loads. (Domestic hot water is completely separate from this system.)

I just fired up all the zones and from left to right they are: 5, 8, 4, and 2 gpm. 19 gpm total.

You ask about stainless steel circs and non barrier tube, and I'm sorry, I don't know what either of those questions mean. Are you saying that the circulating pumps are stainless? They could be, I didn't install them so I honestly don't know. I do know that the tubing itself is PEX.

TahoeJohn

hot_rod said:

Are you going to run the DI cartridge in it? That adds some flow restriction.

The distributor I purchased it from suggested that I run the DI cartridge in it for 3 days, then switch over to the anode longer term. My tap water runs between 24 and 27 for TDS.

Looks like 13 gpm is what they show on the spec. So without knowing your actual flow rate we are all WAGing

The manual shows piping options. As a bypass filter you reduce the effectiveness somewhat, adding time for it to clean or DI the entire fluid volume system.

Certainly whatever you do is better than what you have now

Those manual pages are very helpful, thank you. (I haven't received the unit nor manual yet.) If this thing can only handle 13 gpm and I'm running 19 gpm with everything on, it sounds like I should indeed install a bypass with a globe valve, as Ed suggests.

I do like and appreciate your final comment.

hot_rod

I'd check with Roger on flow rate. If in fact it is a 13 Cv device, running 19 gpm would be a small 2 psi pressure drop penalty. Keep in mind the flow rate will change depending on how many circulators are running.

The bypass in theory would need to be able to handle only the flow above the 13 gpm, a 3/4 or 1" may be plenty. No need to put in a 1-1/2 valve and choke it down 90% to get 13 gpm through the device.
They suggest a flowmeter if you pipe in a bypass so you have an idea of what is going where.

A Caleffi 132 Quicksetter would be ideal if you want to know that flow bypass.

If you want the bypass to handle the full 19 gpm to isolate out the unit for example, 1-1/4 is plenty for that short section.