How bad is this proposed radiator layout? White Bear Lake MN professional?

eclecticmn

Long story. Homeowner in New Brighton MN. I cannot get the bottom 1 1/2 plugs out of my hot water cast iron radiators. I bought them used. No central heating in kitchen for 24 years. I think I talked to some plumber from White Bear Lake long ago.

What percent off perfection would this layout be? 1 inch O2 barrier pex B. I mean professionals often compare themselves to perfect. I wonder if I would get any heat.
https://i.imgur.com/hqEIeKa.jpg

Jamie Hall

As you say, not perfect. But with that piping layout, you should get pretty good heat out of the radiators. The key to it is the valves which you show; you will need to fiddle with them to get the balance between the two areas right, but it can be done. Comes under the general heading of "run what you brung".

How much heat you get will depend very much on how hot the water is you push through there, and how much flow you can get.

If all this is going to be on the same pump as other areas of the house, you may also find that you have to adjust them too to get the balance you want.

Kickstand55

Sometimes trying to save a buck will cost a fortune.
More details will bring your idea into focus for us to help, such as house and room size, heat loss calculations, boiler size, piping size and length of runs, pipe insulation, zoning, placement of thermostats(s). If those factors are considered and calculations presented, help can be availed.
Please understand that PEX piping is good in some applications, but consider the fitting size, amount of fittings used and area or cross section reduction. All this poses a restriction as compared to copper piping. Many people including contractors thinking "time is money" in using PEX have been disappointed with the result.
Worth considering

mattmia2

It would be better to connect them in parallel. The way cast iron heats, connecting them in series means they won't all be hot until it has been heating a while. As long as your flow isn't too high connecting both bottom tappings instead of a top and a bottom tapping will work ok.

EdTheHeaterMan

Out of context. That will work fine. If they are the only three heat emitters on the system, they would work great. If there are other heat emitters on the system, I might change my mind depending on the rest of the system's design. For example this will work perfectly:
But, if you have an old 1950s style Monoflo® or any other one pipe diverter system and you are branching off where there was only one existing radiator to add 3 radiators, then the three new (used) radiators will not get very much heat if any.

Context is important in order to answer your Query.

leonz

Go back to your drawing and change radiator 3 to radiator no. 1.

Eliminate both the valves and the tee's for (your) radiator 3 line crossing the feeder pipe.

Pipe your radiator 3 from bottom to top in the single pipe feeding the other radiators installing 2 valves on each of the three radiators, short nipples and unions to reduce any water loss if the radiator needs to be repaired or replaced.

In a pinch it lets you quickly connect a pipe nipple with unions and nipples to maintain flow and heat. Do the same for your radiators 1 and 2.

You could or should have a long piece of PEX with unions on hand sized for the unions on the radiators in case of a leaking radiator or pipe fitting to maintain flow and heat

AS "your radiator no. 3" is going to receive hot water first it would be easy to install an orifice disc on "your radiator 2" to hold more heat in the kitchen space rather than using the valves. If it gets too hot you can open a windowstat.

My thoughts on this anyway.

hot_rod

A home run, possibly with 1/2 or 3/4 pex is another option. Tube size depends on how many BTU is needed. It gives you individual control option. Isolation for each radiator. A zone actuator at the manifold or TRV at each radiator.

Performance wise, each radiator gets the same SWT. With a ECM delta P circ, energy savings and ideal flow rate is also a feature.

An example of a column type radiator at 1 and 4 gpm flow rates. 3/4 tube supply.

mattmia2

Peakedtoosoon said:

If they are all in the same room, you can balance them to achieve their design BTU output, with the current set-up. However you'd need a flow regulation device on each rad, like a lockshield valve, or a return manifold balancing valve.

Since they are in series, if you try to use a balancing valve on one of the series pair it will change the flow to both.

eclecticmn

...

leonz said:

Go back to your drawing and change radiator 3 to radiator no. 1.

Eliminate both the valves and the tee's for (your) radiator 3 line crossing the feeder pipe.

Pipe your radiator 3 from bottom to top in the single pipe feeding the other radiators installing 2 valves on each of the three radiators, short nipples and unions to reduce any water loss if the radiator needs to be repaired or replaced.

In a pinch it lets you quickly connect a pipe nipple with unions and nipples to maintain flow and heat. Do the same for your radiators 1 and 2.

You could or should have a long piece of PEX with unions on hand sized for the unions on the radiators in case of a leaking radiator or pipe fitting to maintain flow and heat

AS "your radiator no. 3" is going to receive hot water first it would be easy to install an orifice disc on "your radiator 2" to hold more heat in the kitchen space rather than using the valves. If it gets too hot you can open a windowstat.

My thoughts on this anyway.

"change radiator 3 to radiator no. 1."
Does this mean I just change the numbers on the diagram?
Would this put all three in series or all in parallel?
BTW I was planning on using all 1 inch pex B as I kept hearing about restrictions.

maybe keep the rad numbers the same as I did then just tell me where the supply goes (1 to 2 to 3 to return. Or supply to 1 to return, supply to 2 to return. etc.
Going out to shovel snow.

hot_rod

#3 will need a balance valve to force flow to the radiators that are farther away, #1 & 2.

1&2 are in series. If #1 gets 180° supply, #2 will get 160 or lower, and as a result lower output.

In parallel as shown in the home run, all would get 180° and have the best output.

But without a load calc and knowing the size of the radiators, we are all just guessing a bit.

leonz

In my opinion if the radiators are all left in series I would use
orifice discs on the pressure side of each radiator in the herd
by piping each them bottom to top.
There is no need to create a cross connection mess with this
in my opinion.

eclecticmn

Thank you. Most of this is over my skill set. Would these orifice discs be different sizes depending on whether they are first, second, or third in line? Maybe I will read a book by summer.

I will likely try something just to see if I get heat at all then try for something better in summer after I find someone to remove the plugs to allow for a less messy pipe arrangement. Maybe build a platform under the two radiators to hide the piping mess caused by the concrete wall below. Pex is easy to change. If it is better than the wood stove or leaving the gas oven on I will consider this progress.

I am very far from being competent in this area.

hot_rod

leonz said:

In my opinion if the radiators are all left in series I would use
orifice discs on the pressure side of each radiator in the herd
by piping each them bottom to top.
There is no need to create a cross connection mess with this
in my opinion.

two radiators in series, even 10, what would an orifice disc accomplish, hydraulically speaking? Unless we are thinking differently about series?

The orifice (restriction to flow) concept works in monoflo fittings to reduce flow in that straight section to push flow out the branch.

EdTheHeaterMan

eclecticmn said:

Thank you. Most of this is over my skill set. Would these orifice discs be different sizes depending on whether they are first, second, or third in line? Maybe I will read a book by summer.

I will likely try something just to see if I get heat at all then try for something better in summer after I find someone to remove the plugs to allow for a less messy pipe arrangement. Maybe build a platform under the two radiators to hide the piping mess caused by the concrete wall below. Pex is easy to change. If it is better than the wood stove or leaving the gas oven on I will consider this progress.

I am very far from being competent in this area.

Can you make a drawing of your complete system? You mentioned Monoflo® but I believe you may not have that system.

Here are some examples I used in my class on Hydronics

Most common in old homes with gravity coal boilers eventually converted to new modern boilers is the upper left Direct Return
Most common in new homes built after 1960 was the series loop using baseboard radiators
Popular in the late 1940s thru the 1950 was the one pipe Monoflo® system. The bottom left design is most expensive design but makes balancing the entire home almost automatic. The Reverse return system had equal pressure drop across every zone or loop or radiator because the first branch on the supply is the last branch on the return. Every branch section has the same amount of pipe distance to travel, be it the first, the middle, or the last.

leonz

If there are no valves on the radiators to slow the water down to heat them
an orifice disc in kitchen radiator or radiators would work.

pedmec

Best bet is to run homeruns from manifold at boiler using pex from manifold to radiators. That way balancing can be done at manifold.

eclecticmn

My system is direct return. Very early on someone else mentioned monoflow devices to push more water into the 3/4 slant fins. The slant fins are gone as is the copper pipe. I had no idea what monoflow even meant. At some point I will draw a very detailed drawing with pipe diameters and run lengths. Right now the boiler splits into two 2 1/2 inch supply mains and two 2 1/2 inch return mains. My kitchen loop take off was a 1 inch tee reduced down to 3/4 before I took off that bushing.

Here is the best drawing I have. I have no idea what a manifold is. My house currently has 6 radiators on the first floor (two currently valved off for now) and 5 on the second floor with 1 valved off for now. I will try to add 3 smaller radiators in the kitchen. There is one thermostat in the house. All radiators have manual supply valves. There are no thermostatically controlled valves on any radiators. Maybe change that someday.

Anything I do now will be an experiment. If I get heat with no added circulating pump I will revise it anyway later when I hire someone to remove the radiator plugs from the bottom of the 3 kitchen radiators.

https://i.imgur.com/YNUIjTO.jpg