Popping in my wall part 2

avidrissman

I own a co-op in Manhattan, and last year I posted a cry for help here and you folks rightly called me out on my terrible installation of cast iron radiators. So last summer I had my radiators replaced, to make sure that my heating installation was not something that could be criticized. I’m happy to call the installation a success, and now I don’t have to worry about 300 pounds of cast iron being wobbly and threaten to fall over. However, I still experience bad popping in my wall.

The new radiators are Runtal’s Charleston Pros. They are lightweight and bolted to the wall, so that entirely eliminates the precarious balancing of the previous cast iron radiators I had.

However, since there is still a vicious popping in the wall, I’m looking for things that might be a problem. There are two possibilities I’m thinking of, and thus two questions that I have.

The first is the piping to the new radiators. The plumbers, when installing the new radiators, did not change the piping that was already there for the old radiators. In the living room it looks like:



and in the bedroom it looks like:



Question 1: is that reasonable piping for my radiators? In particular, that long piping in the living room makes me feel unsettled. That’s a very long, nearly horizontal pipe. I think it’s pitched slightly, but would that be an issue? Is the piping in my bedroom reasonable?

The second question that I have is pressure. The instructions for my radiators say that the minimum pitch for the radiators is 1/16ʺ per foot. And I do have that much pitch. However, my co-op runs the boiler at 5 psig, and I haven’t yet been able to convince them to turn it down to something reasonable. Question 2: does running a boiler at a higher pressures require a more extreme pitch on the radiators to compensate?

Thank you for your advice.

mattmia2

This is 2 pipe steam? Where is the steam trap?

avidrissman

One pipe steam, sorry, forgot to specify.

mattmia2

Oh. it is 2 different radiators. could be piping binding on flooring like you had or framing anywhere in the wall, or water hammer where a pipe is holding condensate somewhere.

mattmia2

Your piping looks fine as long as it has pitch toward the riser. Would be better to have the valve in the vertical section or an angle valve on the horizontal one. Are the valves all the way open?

neilc

did you ever get elected to the board?

Jamie Hall

Nothing if not creative... but if it's a popping sort of sound, rather than a clang or a bang, I'd be betting o the pipe rubbing on the floor -- on both of them -- where it comes through. See if you can sift the radiators -- just a bit -- just enough to slip a piece of a plastic milk or OJ jug in between the pipe and the flooring and see if that helps.

avidrissman

@neilc Thank you for remembering! No, I didn’t get elected to the board. Will be trying again this year with the Local Law 97 fracas.

The popping happens in the wall with the riser near the ceiling and sounds like a cap gun, but loud: https://youtu.be/ENXB7Sq4FLg

The popping sounds like it’s coming from near where the radiators for the apartment above me split from the riser, but when we did an experiment in turning off their radiators, it didn’t change anything.

mattmia2 said:

Oh. it is 2 different radiators. could be piping binding on flooring like you had or framing anywhere in the wall, or water hammer where a pipe is holding condensate somewhere.

“binding on framing in the wall” is the worrying part; the contractor who I used for the remodel wasn’t the best, and they totally could have screwed this up.

mattmia2 said:

Are the valves all the way open?

Yes, the valves are open all the way.

Do pitch requirements change with the pressure? I’m going to be running for the board again, as they aren’t listening to my complaints about running at 5 psig. The new big thing in NYC buildings is worrying about Local Law 97, which is a fine for poor energy efficiency. If elected, getting the pressure down should help us with efficiency. Does anyone think that the popping is related to high pressure?

avidrissman

Also @Jamie Hall you’re the only person so far making distinctions about the sound. When you watch the embedded video above, what does it sound like to you?

mattmia2

avidrissman said:

The popping sounds like it’s coming from near where the radiators for the apartment above me split from the riser, but when we did an experiment in turning off their radiators, it didn’t change anything.

mattmia2 said:

Oh. it is 2 different radiators. could be piping binding on flooring like you had or framing anywhere in the wall, or water hammer where a pipe is holding condensate somewhere.

“binding on framing in the wall” is the worrying part; the contractor who I used for the remodel wasn’t the best, and they totally could have screwed this up.

As the piping all up the building heats it all expands and needs to go somewhere. piping heating lower in the building cold be causing the piping above you to move, just because you turned of those radiators doesn't mean that that piping isn't going to move as the system heats and cools. Water hammer is a lot less likely to happen in the closed off piping so that leads to it more likely being expansion noise.

avidrissman said:

Do pitch requirements change with the pressure? I’m going to be running for the board again, as they aren’t listening to my complaints about running at 5 psig. The new big thing in NYC buildings is worrying about Local Law 97, which is a fine for poor energy efficiency. If elected, getting the pressure down should help us with efficiency. Does anyone think that the popping is related to high pressure?

No. the pressure will cause the steam to be slightly hotter but the piping will still expand and contract the same. It could have some effect on water hammer. The condensate will return about the same regardless of pressure although running higher pressure could make bad near boiler piping that throws water up in to the system worse.