Correcting my 2 Zone Monoloop System (Need Help)

JWieg727

thank you all again. I'll get some time this week and weekend to mess with it again and report back if I was able to solve my issue. @EdTheHeaterMan , @mattmia2 , @offdutytech

JWieg727

Alright! Got some time today to play with that branch that goes to the office and hallway. Was able to use a special webstone ball valve that has a hose spicket to force the rest of the air out of the line. It empties from the side of the ball valve that comes from the radiator.

I connected my capped off loops for a bypass.

Turned up the speed one notch on my circulators

And cut the boiler on. I let it get up to temp and the branch appears to be getting flow now!! So we are in business now. Operating as it should. This should get me through just fine until I decide to switch up my circulator arrangement.

One other question. My fill valve is just tap water. I have a couple runs of pipe that are on outside walls but wrapped in insulation. Do I need to put a refrigerant in my lines?

We didn't have it last year and seemed to be fine but trying to do things right here. These lines go right through my brand new kitchen walls so I'd be even more upset if these were to rupture but then again they didn't freeze last year and they were not getting any flow really. Let me know your thoughts.

Thanks again so much for all the help. I'm glad to be up and running again and have a much better understanding of how a monoloop should work and how it was designed originally!

Thanks,

Jake

LRCCBJ

Well done!

With regard to piping in exterior walls, you will not get a consensus. Some are totally against it, especially if you lose the boiler (generally due to a power outage) at extremely low temperatures.

Personally, I have been successful actually MOVING piping to the outer walls. I insulated the 3.5" bay with 2" styrofoam against the sheathing and leave open 3/4" copper piping in the small space left between the styrofoam and the sheetrock. This warms the bay every time there is flow through the piping. Additionally, since the sheetrock provides minimal insulation, the elevated room temperatures serves to maintain the temperature in the bay. Unlikely to freeze unless, again, there is a loss of the boiler for an extended time, at extreme cold temperatures for any reason.

JWieg727

@LRCCBJ Thank you!.

Ahh its one of those topics…. ok thanks.

I ended up doing something similar with these prior to sealing the walls up. I put 2" foam board on the sheathing and sealed the edges with some silicone. Then I split the fiberglass insulation in half, putting the first half in prior to the 3/4in piping. Then I just put the rest of the fiberglass insulation over it, sandwiching the piping. Hoping that will prevent any freezing in case of a failure.

LRCCBJ

https://forum.heatinghelp.com/discussion/comment/1814032#Comment_1814032

You're welcome.

I mulled over your system approach for weeks before deciding on no piping insulation. Here is why:

Without insulation, the piping will warm the entire bay and the bay has "some" volume to it. To cool the bay below freezing will require quite a bit of time, especially since the room is continually warming the bay to an extent………..as the room cools.

If the pipe is insulated, the bay is considerably cooler than the room temperature and it will approach freezing much faster than the uninsulated pipe. Of course, the insulation will keep the pipe from cooling as fast as it otherwise would cool without same.

However, I have the suspicion (without data) that the warmer bay would last longer before the pipe drops below freezing.

The entire discussion is academic if the boiler has power and continues to deliver energy to the piping. If power is lost at very cold ambients, neither solution will last indefinitely.

JWieg727

@LRCCBJ interesting.. when you say "bay" im assuming you are talking about the wall cavity?

Seems counterintuitive and possibly dependent on "how" its insulated. I can see why adding specific pipe insulation would cause this as it would prevent the cavity or wall insulation from warming up. However, I've actually embedded the uninsulated pipe in the middle of the wall cavities insulation and sealed the cavity to prevent any outside air from entering the sheathing. Would you think this would still result in faster wall cavity temp decline than if I just used the 2" foam board against the sheathing?

Just a note, I think I'm fine as it is and the differences could be negligible. Honestly, just itching my curiosity now.

LRCCBJ

Correct.

With XPS, you'll get an R value of approx. 10 for the 2".

Typical wall cavity fiberglass insulation is about R-11 for the full 3.5". Once you start attempting to get the piping in the "middle" of wall cavity fiberglass insulation, you'll probably result in something around R-5 or so. Furthermore, you're not warming the bay as much as the open pipe.

As mentioned previously, it's a bit academic as the determination of whether either of them freeze is largely dependent on how long you are without the boiler combined with both the the outdoor AND indoor temperatures. If you are near zero, the clock is ticking relatively fast!!

If there is a gas stove present in the building, you can maintain the spaces near the stove at 50F or more. This would lengthen the time before the bay drops below 32F.