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jeffjordan
Advanced Member
Bazaar
Kansas
USA
29 Posts |
 Posted - Jun 30 2010 : 5:20:49 PM
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I have posted before about the noise problem in the basement of our house where the 1 HP Myers Jet Pump and pressure tank are located. The sound is very loud in the adjacent bedroom. I need to either (1) build a wall inside the bedroom wall for sound proofing or (2) build a sound proof box around the pump/pressure tank. Number 2 is EASIER by far, but I am concerned about heat. The box would be about 3’w x 4’l x 4’h to cover both the pump and tank, so quite a bit of air inside but no circulation. Cold water of course comes into the pump and tank so there is a cooling source…. Should I be concerned about sealing this off in a box? If it matters the pump is wired with a 220 circuit.
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Edited by - jeffjordan on Jun 30 2010 5:31:43 PM |
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lkoops
Senior Member
Michigan
193 Posts |
Posted - Jun 30 2010 : 11:09:06 PM
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| If your concerned abt. the heat put in a vent on the box your going to build. |
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speedbump
admin
Riverview
Florida
6268 Posts |
Posted - Jul 01 2010 : 08:29:43 AM
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Maybe a vent at the bottom to let cooler air in and one near the top to let the heat out. It will be self ventilating that way.
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jeffjordan
Advanced Member
Bazaar
Kansas
29 Posts |
Posted - Jul 01 2010 : 09:44:05 AM
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| I can vent it but the vent will also transmit sound out of the box. Was hoping to kill as much noise as I could. If it needs air (the water tank woudl not dissipate enough heat) then I suppose I could put louvered vents with a temp controlled fan to exhaust above say 100 degrees in the box for example. ??? |
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speedbump
admin
Riverview
Florida
6268 Posts |
Posted - Jul 01 2010 : 09:49:17 AM
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The motor itself has a fan to move cool air over the windings. If you let that air in the box heat up, the motor's fan is kind of useless. I don't know if you've ever laid your hand on a motor after it has ran for 5 minutes or more, but it's already hot enough that you don't want to leave your hand there long. So, capturing that heat in a box, may not be a very good idea.
And no, the tank won't make much difference other than adding moisture to the air.
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JustWellWater84
Senior Member
Florida
364 Posts |
Posted - Jul 01 2010 : 12:16:28 PM
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| I dont know if i read or remember your earlier posts. So the normal factory running sound is too loud for the bedroom? Or are the bearings going, making the motor louder than normal? If the pump is just on the other side of an indoor wall I could see how it might be a problem. |
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jeffjordan
Advanced Member
Bazaar
Kansas
29 Posts |
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speedbump
admin
Riverview
Florida
6268 Posts |
Posted - Jul 01 2010 : 1:09:58 PM
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I have installed a pile of jet pumps over the years both inside and out. It's rare to almost non existant that a good quality jet pump makes much noise unless it's cavitating (starving for water) or the motor has bad bearings. That is of coarse unless the pump came from Sears or somewhere else where they sell plastic pumps. They are loud out of the box. It just seems like there must be some sort of vibration being set up somehow and causing this noise. These things are very difficult to troubleshoot. I know, I've tried several times in the past and must admit wasn't too successful.
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jeffjordan
Advanced Member
Bazaar
Kansas
29 Posts |
Posted - Jul 01 2010 : 1:38:32 PM
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This one was sold to me by .........
Pumpsandtanks.com. :) It is a Myers pump so I assume good quality. I agree the sound may be as much vibration as anything but I have done all the isolating of the plumbing that I know how to do. It has a supply of probably 20-25 GPM from the well that is a mile away (another pump is at the well with a pressure tank there as well. The pump in the house is a booster pump because the pressure at the house over that distance is only about 15 pounds. It is looudest when it first starts to run and it almost sounds like you can hear the tank filling - the water rushing into the tank - when you are in the bedroom and it gets quieter as it runs and refills the tank. No one will sleep in the beedroom because if the pump comes on at 3AM it wakes you up. |
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speedbump
admin
Riverview
Florida
6268 Posts |
Posted - Jul 02 2010 : 09:08:42 AM
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A mile away. I didn't know that part until now. Or maybe you mentioned it in your last post. What size is the pipe that runs that mile?
This sounds like cavitation to me.
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jeffjordan
Advanced Member
Bazaar
Kansas
29 Posts |
Posted - Jul 02 2010 : 09:47:52 AM
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| It is a very old 1 3/4 inch line. Not economically replaceable with a larger line. If you think cavitation is the issue is that because the Myers pump is trying to draw water faster than the supply is providing it? If so do I need a smaller pump or can I add a storage tank in front of the pump? My concern with the later would be sizing it so that it NEVER runs dry while the pump is tryign to pump water out of it. There is not a lot of extra space in the mechanical room. I assume I would need to know how mnay GPM the Myers pump draws and make sure the tank then was at least as large in storage as the pressure tank on the other side of the pump. |
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speedbump
admin
Riverview
Florida
6268 Posts |
Posted - Jul 02 2010 : 10:04:37 AM
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Either you measured the outside diameter of the pipe or it's a different size, cause there is no 1-3/4" pipe. It's 1", then 1-1/4" then 1-1/2" then 2".
Lets assume you are trying to push 25 gpm (which the Myers pump can do) through that pipe and lets assume it's 1-1/2" pipe. Lets even assume it's plastic not galvanized which has far less friction loss. Pushing is much easier than pulling water, so the numbers are going to be very conservative. I look at my friction loss chart for plastic pipe and see that at 25 gallons per minute there is 4.44 feet of head loss per hundred feet of plastic pipe. Multiply this times 52.8 for the amount of hundreds of feet there are in a mile and we get 234.43 feet of head friction loss. This figure in head translates to 101.5 pounds of pressure loss over the distance of a mile. Now since we are actually trying to pull the water not push it, this figure is on the low side and since this pump is only capable of 60 lbs of pressure in the first place, you can get an idea of just how hard this pump is working trying to get water that just isn't there. Cavitation occurs when a pump pulls so hard on the liquid it's trying to get that it actually pulls the liquid apart and causes little voids which actually implode and make lots of noise. They also tear up the impeller, seal and pump housing slowly over time.
It's my opinion that the noise your hearing is caused by cavitation and the reason it gets quieter when it builds more pressure is that when a pump goes higher in pressure, it's volume drops off, so it's not pulling as hard.
If you had room for a tank, that would be the thing to do for an easy fix. Let the mile of pipe dribble into the tank to keep it full then pull from the tank with the Myers pump.
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jeffjordan
Advanced Member
Bazaar
Kansas
29 Posts |
Posted - Jul 02 2010 : 11:47:50 AM
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| It is PVC pipe and you are probably right at 1 1/2. It is not 2". During construction of the house and before ever installing a pump in the house, I tested the "flow" from the well and had about 20-25 GPM of flow from the end of the pipe in the basement (just FYI we were tying into an existing line, not starting new from the well). This flow obviously comes from the submersible pump and pressure tank at the well head. The pressure switch at the pressure tank at the well is I beleive set to 50-70. I think I understand what you are saying but wanted to make sure you understood what existed. |
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speedbump
admin
Riverview
Florida
6268 Posts |
Posted - Jul 02 2010 : 12:36:25 PM
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quote:
I tested the "flow" from the well and had about 20-25 GPM of flow from the end of the pipe in the basement (just FYI we were tying into an existing line, not starting new from the well). This flow obviously comes from the submersible pump and pressure tank at the well head.
I'm no engineer but according to everything I have for charts etc, what you are implying is physically impossible.
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jeffjordan
Advanced Member
Bazaar
Kansas
29 Posts |
Posted - Jul 02 2010 : 2:27:04 PM
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| I used googlemaps to "measure" the distance from the well to the house along the path the pipe takes and it is only 3900-4000 feet. |
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speedbump
admin
Riverview
Florida
6268 Posts |
Posted - Jul 02 2010 : 3:28:03 PM
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Then you can cut the friction loss which remember is pressure loss not suction loss from over 100 to around 90 psi.
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JustWellWater84
Senior Member
Florida
364 Posts |
Posted - Jul 02 2010 : 10:33:31 PM
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| i like the holding tank idea. let the well pump fill a holding tank at whatever positive pressure it has, then pump from the holding tank with a submersible... it wouldnt be very cheap but i cant imagine how you could get a more quiet system. |
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Texas Wellman
Senior Member
SE Texas
214 Posts |
Posted - Jul 03 2010 : 01:50:19 AM
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Might even try a throttle valve after the pump and see if it helps any with the noise.
BTW: Any pump that cavitates that bad won't last very long. Cavitation will destroy the impellers fast. |
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jeffjordan
Advanced Member
Bazaar
Kansas
29 Posts |
Posted - Jul 19 2010 : 6:10:47 PM
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| Is there a way to upload or send you an audio file (I know it plays in Itunes - recorded from IPhone) to hear the pump and tell me if you think it is in fact cavitating? |
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speedbump
admin
Riverview
Florida
6268 Posts |
Posted - Jul 20 2010 : 12:00:35 PM
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From what we know now, it's most certainly cavitation. If you had bought one of those plastic pumps from Sears, they sound that way out of the box without cavitation. But with your setup, it's most certainly cavitation.
I have sold and installed an awful lot of cast iron pumps over the years and they are all pretty quite until you starve their suction. Then the noise begins.
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Topic |
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Question about Isolating Jet Pump and Heat
