How to Build a Generator Quiet Box (DIY) | Ultimate Stealth Enclosure

By | February 5, 2023
How to Build a Generator Quiet Box (DIY) | Ultimate Stealth Enclosure

In this video I'll cover everything you Need to know to build your own DIY Generator quiet box I'll take you step by step including a List of all the parts that I use in this Video in the description section below I'll also show you some of the mistakes That I made some of the issues that I Ran into with heat and how I resolved Them So let's start off with a discussion About sound as you can see here we've Got about 42 decibels when it's quite my Backyard at this point I'm now talking Out loud about 12 feet away and now We're running the generator with the Box Open at about 80 decibels and then you Can see here with the generator box Fully closed we're running at about 60 Decibels [Music] Regarding the box I just picked up a Shed at a local hardware store that you Can put typical garden tools in you can Get these at Home Depot or Lowe's then I Went down to Tractor Supply and picked Up some horse stall mats the one I Wanted was it available so I had to get Two smaller ones and as you can see one Of them by themselves fits pretty well There was a space that I still had so Taking a quick measurement I was able to Determine how much I need to cut off on The mat to fit into this space and it

Fits like a glove as you can see there's A little space in the back but we'll Address that momentarily now as far as Making Cuts goes what I want to do is Measure out on both sides the items that I'm going to be putting on the side the First item is a air intake just a basic Attic vent that I was able to pick up at Home Depot I started off by making a few Small holes with my drill and then I was Able to get my reciprocating saw in to Make the bigger Cuts just make sure you Stay inside of the line that you outline Whenever you're measuring out your Object that you'll be putting in in this Particular case event next I added some Fire block foam and then once it's Settled and then I slowly pushed in my Vent next I drilled some holes so we Could put in our bolts I used some Galvanized metal here because it will be Exposed to the elements I also picked up a few washers and a few Small bolts went ahead and went on the Other side and as you can see I just Attached the bolts and the washers and I Was able to securely tighten this down Next I picked up some dynaflex sealant As we're going to be exposed to the Weather obviously and I just want to Make sure we don't get rain or water Inside of our box Now as far as the next time that we're Going to cut on the other side I've got

A blast gate and this will be used to Run out our power cord and also our hose To our gas propane tank and I just want To keep everything outside especially The propane tank so I went ahead and Again cut a hole with my drill so that I Can get my reciprocating saw in here as You can see again I just took the Approach of cutting on the inside of the Red line trying to avoid going on the Outside Now the issue that I ran into very Quickly is once I put this in I notice On the outside I've got a big caping Hole where water and other things can Get in so what I did is I picked up some Galvanized sheet metal In measuring off about three inches I Was able to again cut this make sure That you wear gloves during this process Because this can be razor thin on the Sides I went ahead and slid it into the Hole to get an idea of how much I'm Going to be working with and then I Began to cut small incisions about inch Inch and a half every three or four Inches going around and what I want to Do is kind of spread the metal out to Again create a barrier so that I don't Get rain and other stuff inside of the Box So now that I've made the small Incisions I just went ahead and began to Bend each one of these tabs back and as

You can see in just a second what we're Trying to do is just splay it out in a Way that I can then screw it on to the Sides so that it will be firmly attached So now that I made the cuts I was able To line this up and put it inside one of The things I did notice is that the Metal is pretty rounded on the edges so I went ahead and put it in my clamp to Tighten down and really Get those edges nice and closed off so I Don't have the round edging around each One of the tabs Now I went ahead and slid it back into The hole inside the blast gate or rather Between the blast gate and the wall and Then I just screwed it down with some Simple screws now on the other side the Blast gate I went ahead and wanted to Mount this so it's securely up against The wall and I just found these small Tabs at Home Depot and just making some Very small holes I was able to do some Pre-drilling and then drop in the Different screws all the way around it Doesn't look perfect but it's good Enough for our purposes of keeping it Securely in place So now it slides up and down perfectly Allowing us to run our hose to our Propane tank and our cord that we're Going to run out to our electrical Outlet Next I went ahead and made the

Measurements for our fan that we're Going to be sticking in If I made one mistake in this process it Was at the fan that I got was a little Small if I were to do this again and I Might go back later and just add in a Larger fan I just got an attic fan from Home Depot these are designed to handle The heat Now I went ahead again and put the fire Block foam in here and as you can see The exhaust fan it goes on the outside Originally when I was playing around With it I accidentally put it on the Inside but it mounts perfectly on the Outside and again this will draw the hot Air through our box to pull that air out From the intake on the other side I Purposely put this fan at the top of the Box as the heat rises I wanted to Capture that hot air and I put the Intake on the left side I put that at The bottom so once I mounted this up I Again went ahead and put the Silicon Around the edges of all of the things That we cut holes in on the side as you Can see I'm doing this on the exhaust Where the exhaust pipe comes out which We'll talk about momentarily The next thing that we have to really Factor in is our insulation because a Generator running inside of this box can Get pretty hot sometimes up to over a Couple of hundred degrees so we want to

Make sure that whatever we put in here Can handle this without melting or Having any heat issues on several videos I saw online people are using our Max This melts at 250 degrees and I read the Comments of one of the videos that was Most popular on this particular setup People posted that they actually had Theirs melt and almost catch on fire so This is why I use rock wool Comfort Board it's actually rated for 2150 Degrees there's videos online of people Putting torches to it and it's perfectly Fine so I spent a little extra money and I was able to find one out of local hose And I got some screws again washers I Think the screws are about two and a Half inches and I went ahead and drilled Those in now the rock wool is about an Inch inch and a half thick so you have To make sure that whatever the screw is It will both go through that and also Mount into the plastic Since rock wool is easy to work with you Can easily cut it draw the lines where You want to cut it with a knife and then Again using the different screws and Washers just mounted on some places were A little trickier as you can see here I Had to measure everything perfectly draw Down on paper where I was going to make The measurements and then I had to go Over to the rock wool Comfort board and Make those same measurements to cut

Exactly so I knew where to mount this So now that I've made the cuts I was Able to line it up on the wall and as You can see everything fit perfectly Snug and where I've made the Measurements I did the same on the other side just Finishing everything off And I also added it to the doors Now it does add weight to the doors so Whenever I open them I try to support Them the best I can Lastly I went ahead and mounted this on The inside of the top of the shed as you Can imagine as heat rises this area Specifically is going to be impacted so You want to make sure that you mount That up on the top of the inside Next what we'll do is we'll talk about The exhaust pipe what I did is I made a Mistake of buying this metal flange I Saw someone did it on a video and they Ran their metal exhaust hose through This from their Muffler as you can see Here we're going to run our exhaust out But the problem is that he transferred So quickly to that metal flange and Heated up the side now as you can see Here I'm wrapping this up with a Fiberglass material that's designed to Wrap around the exhaust systems of Motorcycles and other you know Vehicles It does an okay job of keeping the heat From being too much but be careful when

You're working with this material make Sure you wear gloves long sleeve shirts And a mask because of all the fiberglass Next I got the muffler Intel pipe sealer And I put this on a connector put the Glue here on the inside and this is Designed to connect the muffler to the Exhaust hose as you can see here I'm Sliding it onto our exhaust hose and We'll bolt it down in a minute but as You can see I'm sliding it into connect Effect with the muffler exhaust Now next I have these brackets I'm going To mount these on the wooden fence and It really helped to prevent transferring The heat from our exhaust hose over to The wooden fence there was a negligible Amount of heat I might go back later and Put some material behind it to prevent Any heat transfer especially on wood the Brackets helped hold the exhaust hose Off of that wood pretty well Again make sure you're careful when You're working with a fiberglass to wear Gloves and a mask I found myself itching for several days After working with this material As you can see when we're running this We get up to about 180 degrees or so on This exhaust hose coming out it wasn't Too bad now a second ago I mentioned That I had problems with that metal Flange transferring the heat so I went Back and I ended up pulling it out

Because it was just transferring way too Much heat I bought this three inch dryer Vent at Home Depot another video someone Had done it this way and I loved it I Ended up putting that in and I went down And bought some Springs At Home Depot And I shoved these in underneath that Exhaust hose coming off and it was it Did a perfect job of keeping that hose Centered where the heat didn't really Transfer over to that dryer vent using Our temperature gauge here I saw the Hose was running about 300 degrees 290 Right there when it comes out but on That dryer vent it was only around 90 Degrees barely transferred the heat now Next I put a small block up here on my Fence what I did was I hung a motorcycle Muffler up here I specifically chose This Muffler after looking online and The engine type and and everything just Kind of lined up well enough with this Muffler that we didn't get a lot of Pushback on the engine from the exhaust And again this was designed for about a 400 cc motorcycle and it was able to Help drop the noise significantly When I ran this it got up to about 140 Degrees give or take now one other issue Is on our air intake in the exhaust of Course noise is going to escape so what I did is I built boxes I did a lot of Measurements first and I really wrote Down all of the measurements in advance

And use that information to cut out with The a piece of old plywood that I had to Cut out the pieces to make these boxes Which I'll take you through the process After I cut them I just sanded them down Because plywood can get a little Splinter on the edges using wood glue I Was able to just glue everything Together at first to hold the frame in Place and as you can see in a minute I Then went ahead and nail it down once The glue had set also on the end because The ply was was so thin I just used a Staple gun next I drilled small holes on The side because I want to run bolts Through again to hold the insulation on The inside Just punching that bolt through put the Washer on and then I screwed on these Bolts I got a couple of hooks at Home Depot and I just measure on the side of The box the same height and just mounted These on I did this to hold up the Exhaust box here and again as you can See looking inside there's a small Opening at the bottom as the sound comes Out it has to take a nine degree turn And then another now you need to get out And of course this helps reduce the Sound as you can see the exhaust coming Out was about 150 degrees This is a process of setting this up it Takes me about four minutes pulling Everything out as you notice I pulled

The tank the propane tank out I do not Leave that inside while operating this Because if it overheats or whatever Reason catches on fire I don't want that Tank inside and again that's why I put The tank on the outside running the hose To the blast gate And that's it that's our generator shed If you have any questions feel free to Post it below as always stay safe out There