So you run a generator to make some power at the field, and everyone’s upset. I guess that generator is just too loud, right? It seems like no matter what you do there’s still noise coming out of that thing. You can’t go on with it sounding like that!! Well, I’m here to help!
How does a generator work? What makes generators noisy How to quiet a generator down. First off, how does a generator work? A generator produces electricity by spinning coils inside a magnetic field. This is called Faraday’s law:
So, if we hook up a coil to an outside magnetic field and spin it (like via wind or water flow), electricity will be produced! The faster the coil spins, the more voltage will be induced. In the case of a generator, this voltage is used to power/charge whatever device you plug into it. What makes generators noisy?
Now that we know how they work, let’s talk about why they’re so loud… The noise from a generator comes from several sources:
1) Magnetic coils vibrate against each other and create sound
2) fan blades vibrating against air
3) Gear grinding together
4) Shaft bearings grinding against their housing
We’ll be talking about the first two. How to quiet down a generator. If you want to make your generator much quieter, here are a few tips: Don’t run it at full throttle when trying to figure out how loud it is Run it in an airtight building with minimal ventilation Remove the choke from the carburetor and close up all vents/grills Tighten loose bolts on external parts of the machine.
Home test for faulty valves Do not use oil-based lubricant Don’t put anything flammable near or in it (generators get hot) If you have a leaf blower, blow compressed air across the spinning blades If you cande magnets so fast they produce an electric current. This process creates lots of heat as well as noise – which is annoying if you’re trying to enjoy the field.
My favorite way to make a generator quiet is by putting it in an airtight container… this sounds crazy, but it works pretty well for me! And I can tell you that making generators quieter makes everyone happier. So if you want the field to be happy, try out one of these tips!
PLACE SOUND DEFLECTORS
Using the above information, here are some experiments you can conduct to find out what makes a generator quiet.
1. Fill an airtight container with sound deflectors and let it run at full throttle for an hour. Then without removing anything, compare its volume to that of an identical unit running in open space. Is there a difference? If so, how much? What are possible causes of this difference? What does this tell you about the relative benefits of each configuration?
2. Find or make two thin sheets of cardboard or aluminum foil (one will be used as a control). Cut holes in one which will line up loosely with fan blades on the generator’s spindle, but not too closely. Slip the control sheet between these blades and measure how much noise they produce. Repeat with your sound deflector. How do they compare?
3. Find a generator with a closed housing which has one or more small vents, such as those made by Coleman or Honda. Place duct tape over all of these vents so the face of the machine is airtight – you may need to remove some non-essential parts from around its exterior for this to work properly.
Then cut out holes in the tape corresponding with fans on either side of the spindle, allowing them to pass freely into and out of the box without interference from anything else (you may have to bend/remove connectors for this). Measure the volume of these fans with and without the tape. Do they produce different volumes? If so, is one quieter than the other?
4. Find a generator with a wide-open housing that has one or more small openings, not including vents (like those on smaller generators made by Briggs & Stratton or Yamaha), such as those shown below:
Imitate their design without actually cutting holes in anything! This may require some careful work with a hobby knife, but it’s usually possible to create a mask that will slip over the face of your generator and cover all openings while allowing you to attach/detach it easily. Then measure noise again – how does it change now?
5. Find a generator with a single small hole for air intake, like those made by Kohler and Honda (seen below). You won’t be able to cover this up without making your own housing; instead, measure its noise as it runs normally and then with the same amount of air being sucked in from another source – maybe you can find one that’s very similar in size!
6. Make two cuts into the wall of your generator’s housing where fan blades are located – about halfway toward their center – so that they allow some air to escape upon rotation. This will reduce how much pressure builds up inside but still trap all dust/dirt. Measure noise again without any duct tape or other sound deflector materials.
7. Find a generator without a solid housing, like the one in the photo below, and mount it in an open-faced box or onto something that will act as an enclosure (think “box within a box”). Add sound deflectors to its exterior if possible – maybe they can be slipped over it somehow? If you’re ambitious, make your housing out of wood! Measure noise again.
8. Here’s my favorite thing to do with generators: take them apart layer by layer until there’s nothing left but magnets encased in metal! Keep track of how many layers you remove… then compare noise measurements (if you’ve found all three types of magnets in one generator, this will allow you to compare the effects of each type). What do these numbers tell you about wherein magnetic field sound waves are formed?
9. In all of your tests, make note of any other conditions which may have affected your results – were you indoors or outdoors? Were there people around who might affect how loudly they were willing to run it? Did the wind blow from different directions during testing and/or when in enclosed vs open spaces? What else makes a difference that might be related to noise generation or sound deflection?
10. Refer back to the original question: if possible, find a generator with closed housing which has extra space for a fan behind its blades, so that it functions more like a turbocharger on a car. In other words, there’s no need for an enclosed box because the blades themselves serve as sound deflectors – see if you can figure out how to add duct tape or holes to the housing in such a way that they don’t interfere with this design!
