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How to stop vents from whistling

Pete:

This morning I was able to notice that the whistling radiator vent is venting before the Gortons on the main completely closes.
Steve from Denver, CO

Comments

  • Steve Garson_2
    Steve Garson_2 Member Posts: 712
    H

    Steve from Denver, CO
  • Steve Garson_2
    Steve Garson_2 Member Posts: 712
    How to stop vents from whistling

    Steam System: WM SGO-4 serving 450 EDR with steam and 25 feet of baseboard via heat-exchanger.

    On steam cycles, the radiator vents whistle.

    Have done the following so far:
    1. Checked that vents work by blowing through them
    2. Confirmed that main vents (Five Gorton #1) are clean.
    3. Checked that all pipes are insulated, including cutting a hole in the ceiling to check those.
    4. Installed Vaporstat to reduce pressure to max of 6 oz.
    5. Yesterday: had heating company reduce firing rate from the 1.1 gph nozzle to a 1.0 gph nozzle.

    Still have whistling, just a bit quieter. WM tells me that the boiler should not be fired at less than 80% of the spec or else there will be sooting.

    I am at a loss on how to fix this. The old steamer generated steam real slow, so this wasn't an issue.

    What do I try now? Do I use vents with the next larger orafice? One radiator in particular is the loudest.

    Is this just something that I should learn to live with?

    Steve from Denver, CO
  • Steve Garson_2
    Steve Garson_2 Member Posts: 712
    How to stop vents from whistling

    Should I just learn to live with?
    Steve from Denver, CO
  • Steve Garson_2
    Steve Garson_2 Member Posts: 712


    I tried a variety of vents sizes:

    Big vents go "whoosh".

    Small vents whistle.

    Adjustable vent moves from a whistle, to silent, to whoosh; put as the pressure build more, the silent becomes whistle.

    I'm stumped.
    Steve from Denver, CO
  • Pete_18
    Pete_18 Member Posts: 197
    Curiosity

    Out of curiosity, what brands of radiator vents have you tried? I assume you've tried Gortons on the radiators themselves and it makes no difference?

    Are you sure that your 5 Gorton 1s are sufficient for your main(s)? If you post the width and distances, I'm sure Steamhead or someone will make sure you have sufficient venting capacity.

    Are your main vents at the end of your mains or at the end of your returns? If they're at the end of the returns, I believe you'll need to make sure you have figured all of that extra space in to the amount of air you need to vent.
  • Long Beach Ed
    Long Beach Ed Member Posts: 1,780
    Yea Steve...

    It's all in the venting. Either the mains don't have enough venting or the radiators don't.

    The steam could be picking up water somewhere, as in a runout entering the main from the side or from a badly pitched pipe. That, too can cause noisy vents.

    Or the radiators could be too big or of poor design.

    But I'll bet you need more venting. Use the Gortons. They are quietest. Forget anything from Home Depot.

    Long Beach Ed
  • Steve Garson_2
    Steve Garson_2 Member Posts: 712


    Here are the venting details:

    Two mains with 30-feet of 2-inch pipe each.

    One of the mains is vented with two Gorton #1 connected at the end of the dry return, where it turns down to the boiler. So there is an extra 30-feet of 1-inch pipe for the dry return.

    The second main has two Gorton #1 connected to a tapped hole in the main five feet from the end, since that part is buried in the ceiling. This main also has a vent located 17 feet from the end of the main, where the dry return drops down to become the wet return. This is also 1-inch pipe. Originally, this was the location of the only vent. I added this vent in the hope of resolving the vent noise, even though I know it makes the system out of balance.

    The radiator with the most venting sound is connected to the end of the main with the two vents five feet before the take-off, with an additional eight feet of feed pipe.

    Is this the info you need to determine if I need more venting?
    Steve from Denver, CO
  • Steve Garson_2
    Steve Garson_2 Member Posts: 712


    So if my calculations are right:

    30 foot main: 282 cubic inches
    17 foot dry return: 51 cubic inches

    30 foot main: 282 cubic inches
    30 foot dry return: 90 cubic inches

    But we don't really want to to vent beyond the end of the main, right?

    Steve from Denver, CO
  • Bob W._3
    Bob W._3 Member Posts: 561


    30 ft. of 2' main would be about 1131 cu. in. or about .65 cu. ft. According to Gill and Pajek's charts two Gorton No. 1's should do it. If you add the dry return I would go with a No. 2; can't hurt.

    Calc: pi r squared time length; 3.1416 x 1 x 12 x 30; divide by 1728 to get cu. ft.
  • Steve Garson_2
    Steve Garson_2 Member Posts: 712


    So if the noisest radiator is on the line with three #1's, what now?
    Steve from Denver, CO
  • Bob W._3
    Bob W._3 Member Posts: 561


    My rad vents "breathe". Thats how I know they are working. Wouldn't care for a whistle though. Almost sounds like you are making too much steam for the installed radiation. I vaguely recall your earlier posts some time back - did you remove radiation?
  • Steve Garson_2
    Steve Garson_2 Member Posts: 712


    No, the boiler is sized for the load: 450EDR. I just dropped the firing rate. The noise isn't unbearable. It's just a bit annoying, since the heat was silent before the new boiler.

    The kids laugh because the "radiators are singing"
    Steve from Denver, CO
  • kevin coppinger_4
    kevin coppinger_4 Member Posts: 2,124
    what does....

    the near boiler piping look like? What pressure is the boiler running at? kpc

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  • brucewo1b
    brucewo1b Member Posts: 638
  • Bob W._3
    Bob W._3 Member Posts: 561


    You could try the double venting trick on the larger or noisier rads. Or maybe venting the risers and slowing the venting on the rads.
  • Steve Garson_2
    Steve Garson_2 Member Posts: 712


    The near boiler piping is to spec. I'll post a photo this evening.

    If I vent slower, the whistling is louder.
    Steve from Denver, CO
  • Pete_18
    Pete_18 Member Posts: 197
    hiss........

    When you're hearing all of the hissing out of this radiator, does it appear like your Gorton 1s on this main have already closed?
  • Steve Garson_2
    Steve Garson_2 Member Posts: 712


    Yes. It only occurs once the pressure in the system rises above 1 ounce.
    Steve from Denver, CO
  • Steamhead (in transit)
    Steamhead (in transit) Member Posts: 6,688
    Try skimming the boiler

    Your main vent sizes appear OK. I bet you have oil sitting on top of the boiler water, which the steam must break thru. When it does, its velocity is higher and it pushes the air out faster for a moment. This can make vents whistle.

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  • Steve Garson_2
    Steve Garson_2 Member Posts: 712


    I'll try that. How much water should I skim off?
    Steve from Denver, CO
  • Steve Garson_2
    Steve Garson_2 Member Posts: 712


    Pete:

    This morning I was able to notice that the whistling radiator vent is venting before the Gortons on the main completely closes.
    Steve from Denver, CO
  • Bob W._3
    Bob W._3 Member Posts: 561


    What I meant was that if you vent the risers and then vent slow you would only be venting the radiators and it shouldn't be so loud.

    I skimmed my boiler again this morning. Took 5 gallons off the top and drained another 3 gallons to get the water level back down to normal. That helped with the venting noises.
  • Steve Garson_2
    Steve Garson_2 Member Posts: 712
    Skimming did the trick

    Steamhead:

    Thanks again for the advice. Another skimming did the trick. How many more time should I expect to need to skim a new boiler that was installed in July?

    Steve
    Steve from Denver, CO
  • Steamhead (in transit)
    Steamhead (in transit) Member Posts: 6,688
    As many times as it takes

    to get all the oil out. It varies according to how dirty the system was when the boiler was replaced.

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  • Steve Garson_2
    Steve Garson_2 Member Posts: 712


    Thanks.
    Steve from Denver, CO
  • Steve Garson_2
    Steve Garson_2 Member Posts: 712


    Skimmed the boiler. I'm just not sure whether I did it enough.

    As a means to test it, I just installed a new air vent on a radiator: Maid-O-Mist #6. I started the boiler cycle and sat and listened.

    The vent was quiet at first. The moisture started to collect inside. A couple of small drops flew up a couple of inches. The is whistled.

    At the end of the cycle, the vent "whooshed" as air was sucked in. I then removed the vent to see how much water was inside. I would guesstimate that there were around ten big drops of water.

    Does this mean that I still need to skim my new boilers some more, or is this normal?

    Steve

    Steve from Denver, CO
  • Steamhead (in transit)
    Steamhead (in transit) Member Posts: 6,688
    Might not have gotten all the oil this time

    try again. Sometimes it takes several tries.

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