I recently bought a small (1,000 watts rated output) power generator. Although it has a 4-stroke engine and its sound is much less louder than my brother-in-law's 3,000watt unit, I still want to lessen its noise level by putting it inside a quiet box. (BTW, a silent type genset of the same rating costs at least 2x more. Honda is 4x more expensive)
So I did a bit of research and found some useful information but also made me think twice because it is not as easy to make as it sounds (no pun intended).
So my first problem is choosing the sound-deadening material. I read something about materials for low and high frequency sound so it means I have to use at lest two types of sound deadening material.
For this, I prefer easy to find materials and google says MDF board can be used. Is this available in local hardwares (especially in the province, Laguna)? I might also use acoustic foam if needed and if readily available. Plywood is not advisable because it readily transmit sound.
I'll just search a design from the net with consideration for effective cooling of the unit, and proper air intake and exhaust,
@ fourtheboys96, thanks for sharing the idea of the quite box. i also have plans of getting a genset for the house as it's really needed here in PH. a quite box is really a good way to lessen the noise - my wife will surely love this as she hates the noise of our old genset in our previous PH home a long time ago. i have 2 cans (750 ml) of spray foam which will expire this May 2015 and i think i can use this material better for the quite box rather than a filler for the barbecue steel drum i'm also working on ... cheers
Boo!
@Boo, I've read about using spray foam as a sound proofing material. But I am leaning towards using MDF boards and some acoustic foam. But I have not found any suppliers yet especially here in Laguna.
@ fourtheboys96, MDF is a excellent board for the quite box as most speakers are made of this board. i don't have any MDF but i do have some extra 4.5mm SmartBoard cement fiberboard from our house construction. just thinking out loud about my plan ... (1) use metal stud/rail (6cm width) to make a box ; (2) use the smartboard to cover all the sides (inside and outside) of the box ; (3) drill a hole 1-2 on each side of the metal stud and spray the foam to fill the area (between the smartboard) ; (4) the top can also be made using the metal stud/rail and smartboard and also filled with spray foam - use hinges to connect it to the side of the box. the bottom can just be any piece of board as flooring to clamp the genset into it ; (5) for the exhaust, i was thinking of just using a 12v DC fan use for desktop PC - i know i have one somewhere na "kinahoy" ko from my desktop before i threw it :-). just cut an opening at the side for it to fit and then connect the wires to the +/- DC terminal of the genset (most of the genset i saw have this). this way, the fan will run when the genset is running ... the only thing to decide is how big the box should be (if possible, i want it to be just big enough to fit the genset) and to allow you to pull start the genset even if it's inside the quite box ... thinking of it now, it's actually quite simply to make, just a frame, cover it, and something in-between as sound proofing 🙂 ... again, thank you for sharing the idea of the quite box ... cheers
Boo!
We basically have the same idea except except for the materials to be used.
Good thing you mentioned the fan because I am trying to figure out the minimum rating of the fan (in cfm) that will prevent overheating of the genset. My small genset has no DC output (too bad!) so that leaves me no choice but to attach a small AC fan (again too bad because of additional load to the gen set).
Anyway, the design in my mind is to have a double walled-box using MDF board and line the inside with some sound proofing foam. I am expecting mine to be significantly bigger than my genset.
I also plan to have the intake and exhaust extended to the outside of the box to allow clean air to come in and emissions to go out effectively.
This seems to be a basic design http://www.campertrailers.org/soundproof_box.htm
Again, for me cooling is important because ambient temp here in the Philippines is high to begin with so enclosing an internal combustion engine needs goo air exchange inside to outside.
@ fourtheboys96 ... i saw the site, 3 exhaust fan for a small genset 🙂 he he he ... definitely not going to overheat ... consider this, by placing the exhaust fan where the motor exhaust is, you don't need to extend it outside ... you can also put another fan (intake), just reverse the direction, near the carburetor for fresh air to come into the quite box ... cheers
Boo!
