Proposed Piping Layout

DJDrew · January 27

Thanks for everyone on this site so far, it has been incredibly helpful in getting our addition setup for radiators. If I could pick everyone's mind again, I'm looking to address a few issues with the near boiler piping.

The system with just the converted gravity piping originally ran best with a AM10 circulator (essentially a Taco 0010). Once the 3/4" zones with zone valves were added, the AM10 circulator was moving the water way too fast through the smaller zones. For the interim, there is smart circulator (UPSe 15-58F) installed, and it has made the smaller zones work better, but the original converted system seems much slower to warm and the radiators at the end struggle.

I am assuming that the necessary circulator to move the water in the old gravity pipes is fairly different than the circulator needs of the newer zones that are only 3/4" copper lines. I also noticed that the system overall is currently throttled by the ESBE, which is great for the boiler but does seem to slow the overall water movement in the farthest radiator lines.

I read Dan's Pumping Away book and think I found a solution… Would the below piping layout let me run the appropriate circulator for each zone and better distribute the heating needs? Am I overthinking this?

Thanks for any thoughts anyone has on this setup.

Big Ed_4 · January 27

Move the zone valve to the return and tie in the feed to the expansion tank connection ..

What is the purpose of the mixing valve ?

DJDrew · January 28

https://forum.heatinghelp.com/discussion/comment/1838369#Comment_1838369

Thanks @Big Ed_4 , the purpose of the mixing valve is boiler return water protection, it keeps the return above 130 degrees. When it is just Zone 1 running, since the piping and radiation was designed for another era, it would take over 45 minutes to get the return temperature over 120-125

The smaller zones, 2-4, never had that issue since the mass is much smaller, but I think I read that Dan's book suggests having the boiler protection in place.

DJDrew · February 15

So as an update…. we were getting ready to do these modifications to the boiler piping so we can finish off our renovations, then the contractor found more wall damage in a few areas of the house. Since all the existing radiators are partially recessed in the wall, he will need them removed for a few days at a time to address wall issues and then fix plaster & paint.

Long story short, for him to progress around the house and still have us maintain heat this winter, I'd have to drain and refill the system several times to compete all the work since all the existing radiators have their supply and return piped into two larger supply/return cast iron mains running the perimeter of the house and there are no isolation valves outside of the boiler room.

I don't like the idea of dumping 87 gallons of water down the drain every week so I can disconnect and reconnect radiators.

Since all the existing piping in this area is cast iron, retrofitting valves is more tricky. One guy suggested cutting out sections and just adapting from the main to copper with bleeder valves and back to cast iron again at every junction (lots of work). Another said to explore cutting out all cast iron mains and transition all drops to pex and run everything into a manifold so each radiator can be individually shut off and removed without needing to take down the whole system (also lots of work).

Would anyone have any suggestions on a preferred path forward we should explore?

Thanks in advance!

hot_rod · February 15

A great application for a hydro sep.

The sep would give you air, dirt, magnetic, and hydraulic separation in one device.

Your loads are now in parallel so the get the same temperature.

In your drawing the loads are in series and will get a different blended supply temperature

IMG_1045.jpeg

DJDrew · February 16

https://forum.heatinghelp.com/discussion/comment/1842873#Comment_1842873

I agree, didn't think about the temperature difference. Good thought.

Would it be better to switch over to manifold setup at the same time to allow me to service the radiators without having to dump all the water in the system every week for the next month or two?

dronic123 · February 16

I thought for a boiler protection loop, the circulator had to be "after" the mixing valve. right after! In your diagram it is "after" the mixing valve but quite aways "after" and on the supply side. I thought that it was all supposed to work better if the circulator was on the return side just after the mixing valve.

But I can see that the circulator will push some water through the short loop. Perhaps that works just as well.

Hopefully, someone can add a comment.

psb75 · February 16

If you are asking about hot_rod's schematic, the circulator IS after the mixing valve. Circ is on the main return line to the boiler. This is the proper orientation for "boiler protection." Distance of circ from mixing valve is not important.

hot_rod · February 16

https://forum.heatinghelp.com/discussion/comment/1842896#Comment_1842896

you could buy or make a 50 gallon drum if DI water and use it over and over. That way you are not adding another batch of minerals with every refill.

When you are finished, run a cleaner, flush with the barrel water, then refill with DI water and some conditioner.

A small 1/2 hp transfer pump to fill and flush from the barrel.

Axiom has an assortment of DI filters to make Deionized boiler fill water.

57A07852-208F-4AB8-AA2A-6C281F5789E9.jpeg

Here is my boiler water, filled with DI and a bottle of Adey HC1. It does have iron pumps, steel expansion tank, some steel nipples, etc

dronic123 · February 16

@psb75 thanks for considering the question.

I was really asking about the OP’s drawing. All of the “ designs” that I have seen for a boiler protection loop have put the circulator after the mixing valve but before the boiler on the return side as @hot_rod did in his design. The OP put it after the mixing valve but also on the other side of the boiler on the supply side but also before the Tee to the short loop to the mixing valve. If this works just as well, it frees up the design parameters. If best practice is to put it in front of the boiler, then that’s where it should stay, regardless of piping the 2 different system loops in either series (OP) or parallel ( @hot_rod ). What say you?

hot_rod · February 17

It looks like Esbe shows pump and valve placement options

IMG_9701.png

DJDrew · March 3

https://forum.heatinghelp.com/discussion/comment/1842969#Comment_1842969

Thanks, that is a good suggestion. If we go with the 50 gallon drum, would it be best to just make a custom adapter that connects to each flange in place of the radiator to act as a cap? I realized spinning off the vale and union at every radiator would be asking for a lot of trouble….

While the original 2" mains that circulate the basement and have 3/4" take offs are a beautiful work of art. Shutting the system down for maintenance is clearly a limitation without isolation valves everywhere. I can see the appeal of an inverted manifold to make this much easier. I just wouldn't expect to get the same longevity out of the pex as all the original iron.

EdTheHeaterMan · March 3

You may want to put the 3/4" loops first on the primary loop, and the cast iron second on the primary loop. The rule is to have the system that requires the hottest temperature first and the lower temperatures second, third and so on. So Radiant floor heat tubing (if you had it) that requires only 120° water will be the last stop on the primary loop.

I swapped the secondary loops to accommodate the higher temperature water for the 3/4" zones.

hot_rod · March 4

the series primary loops with multiple temperature requirements didn’t always work out. They were dependent on the first and second loops running, or the third recievied 180f when it needed a radiant load of 120. So mixing valves needed to be added to assure the lower temperature loads actually hot mixed, lower temperature. It provided hydraulic find, temperature mixing…not necessarily.

P/S doesn’t assure boiler protection either.

if your system doesn’t need two temperature supply, temperature at least 20 degrees from one another, here are two options

The first is a horseshoe parallel P/S, both zones getting the same temperature. Separate air , dirt and magnetic separators

The second is with a 4 in 1 hydro separator, both zones getting the same SWT

DJDrew · March 4

Thanks @EdTheHeaterMan and @hot_rod those are some good ideas. I suppose I could do also it with one circulator for the boiler and one that feeds all the zones to simplify further?

Also, if we did switch to a manifold ease of maintenance as rooms get redone, I suppose I just hook the manifold up as one those zones?

hot_rod · March 4

As long as you can assure adequate flow through the boiler under any condition a single pump sized properly would work. No need for the primary loop that you originally asked about.

Newer, smaller casting boilers may have a minimum flow requirement, check the boilers I&O manual..

The bottom line for flow rate is all the radiators need to get enough gpm to cover the load. Slowing the flow may not get the job done, so bump the speed until you get all radiators performing as needed.

DJDrew · March 4

Thanks @hot_rod. I was considering two circulators to ensure proper flow while the system heats up. From what I can tell, the ESBE really throttles the system during the first 30-35min, and on shoulder season days radiators at the end never get warm since the ESBE never opened up fully, making for some cold rooms.

hot_rod · March 4

These graphics help explain the concept. When the boiler is cold 100% of the flow out of the boiler returns back to the boiler.

So an additional "second" pump pumping across that bypass pipe is only moving room temperature water, not much heating will happen. I'm not sure of the purpose on that particular valve unless it is a low Cv valve? And how does the bypass get adjusted?

With na 280 valve as the boiler temperature starts rising, the protection valve slowly starts to open, think of it a slipping the clutch. The valve is a hydronic clutch. It is not an on/ off valve, it modulates based on temperature.

Once the return is coming back above the setpoint + differential, the bypass closes 100% and the flow is 100% out of the boiler and back to the boiler.

Our largest market is the wood boiler industry. Most of the solid fuel boilers sold in Europe include a return protection valve. Wood or pellet boilers and flue creosote quickly if they run too cold, not a good condition to experience if you have ever been around a chimney fire..

I suggest a 115° sensor cartridge for gas or oil fired. There is an 18° differential, so 115 + 18= 133° is when bypass is shut-off.

(the graphic happens to show a buffer tank, it can connect directly to radiator distribution piping)

DJDrew · March 5

@hot_rod that is very helpful. Thank you for those graphics. I think with gravity converted system like I have, I’m trying to figure out how to get the heat to the end branches/radiators. Repiping it all to a manifold would certainly equalize things, but I hate removing the original pipe that is seemingly still functional.

If I treat the main system as your buffer tanks in the pictures, then slowly moving all radiators over to a TRV as money allows and setting up the main circulator to auto adapt might be the way to get the best heat towards the end without major piping changes. (Doesn’t make it easy to service, but keeps it fairly original.)

Proposed Piping Layout

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