My take on a inverter generator sound deadening box

[Ryno22980]

After the summer camping season is over here in Wisconsin, I use my TT for a trip or two to some primative, public, camping sites to bowhunt in October.

As we know, boondocking in colder weather presents extra challanges. When I had my previous TT, I did the 2 6V golf cart batteries and that worked pretty well. However, depending on how cold it got, it certainly limited us as far as length of stay.

I personally hate the sound of generators. My step-dad had the 4500 watt open frame Champion that we occasionally would use to charge the batteries or run the microwave. Where we camp, the sites are so far apart that the sound wouldn't bother anyone but us. However, the horrible noise echoed off the trees so bad that I assume all wildlife within 7 miles was running the opposite direction.

I toyed with the idea of buying a small inverter generator for these situations. However, the cost of a Honda or Yamaha was really hard to justify when I technically only need a genset for 1 or 2 trips per year. I did some searching and came across garbonz's video on youtube with his Honda running inside that metal toolbox. http://www.forestriverforums.com/for...tor-46516.html

I decided to take a crack at building something similar and put one of the refurbished Champion 73538i from SuperGen Products inside. BTW, at $399, this is the best value available for a solid performing 2000 watt inverter generator.

Here is the video of my result:

https://youtube.com/watch?v=vnoFfqPTogY

The video was taken at 21 feet. I don't have a true decibel meter, but the soundmeter app on my phone was showing a 10 decibel drop with the generator inside the box. Regardless, I was very satified with the result. We could easily enjoy a quiet campfire with it running 20 feet away.

I will take an additional video showing a closer look at the construction inside and out of my project and post it as soon as I can. I started with really small ventilation openings and small computer fans, but it became obvious very quickly that more airflow was going to be needed. Trial and error and lots of temperature testing over several months was needed. I wound up using two 12V 800 cfm automotive radiator fans from eBay powered by an industrial power supply. The power supply is a 10 amp, 24V (fans wired in series) and the fans consume about 180 watts from the generator. The box is plywood and is lined with roof flashing tape and some foam for sound deadening.

To be extra safe, I added an adjustable temperature switch to the inside of the generator. The switch grounds out the ON/OFF switch on the generator if it reaches my set temp. During my final test, I killed power to the fans, closed the lid of the box, and the temp switch stopped the generator in under 10 seconds. This measure should save the generator before it can destroy itself if the fans or the power supply failed while running.

Thanks for reading, and any feedback is appreciated.

[arpipeliner]

Sitting in my trackhoe while guys talking behind me at their machines and the crew in front were hammering out a forty ft rock ledge. The hammer and buckets on rock are very loud. The deer ate the grape vine leaves for about 10 minutes before crossing.

Do understand that you and I both want it quite while hunting. No argument wanted. Just sharing my experience last week.


Sent from my iPhone using Forest River Forums

[Ryno22980]

That's funny. It seems like deer somehow know when it's not hunting season, not a care in the world. Then when you can actually hunt them, one little twig snapping sends them into the next county.

[intjohn]

Yeah, I'm with the previous 2 posts. I boondock on my land 8 months of the year surrounded by state & national forest property and I see deer from trailer all the time even when my generator is running. I have a cummins/onan and its very quiet for a generator so my advice is use a well built QUIet one but I would not .....not use one cause im worried bout scarin off the deer......

Thanx.........INTJohn

[Ryno22980]

I would estimate that I spent about $200 on materials to build the box. That means I paid $600 for my setup and it's certainly quieter than any of the $1000 units.

The box also solves a couple of other problems. If it rains, it's protected from getting wet. It has latches so I can lock the lid and chain the box to a tree for security.

[wnelsonfl]

I worked for a company that supplied the generator industry. Make sure you have ventilation. One inch of acoustic foam does wonders.

[SpringerPop]

Have you considered using a "sail switch" in the air stream created by the fans? It would be one more protective "safety" shutdown.

Of course, there would also have to be a starting over-ride for it, but it would react even quicker to a fan failure.

Since I have also built a "quiet box" for a generator (an open-frame Coleman 5500-watt unit), I am interested in the specific adjustable temp switch you used.

My box uses an old indoor 110-volt "box fan", and has further (very-needed) baffles to prevent noise escape through it.

Pop

[Ryno22980]

Originally Posted by wnelsonfl

I worked for a company that supplied the generator industry. Make sure you have ventilation. One inch of acoustic foam does wonders.

I wanted to add the acoustic foam, but wow, that stuff is really expensive. I also would have had to build the box even larger to accommodate that kind of wall thickness. There are definitely ways I could have done this better, but I was trying to keep it as cheap as I could and still get great results.

[Ryno22980]

Originally Posted by SpringerPop

Have you considered using a "sail switch" in the air stream created by the fans? It would be one more protective "safety" shutdown.

Of course, there would also have to be a starting over-ride for it, but it would react even quicker to a fan failure.

Since I have also built a "quiet box" for a generator (an open-frame Coleman 5500-watt unit), I am interested in the specific adjustable temp switch you used.

My box uses an old indoor 110-volt "box fan", and has further (very-needed) baffles to prevent noise escape through it.

Pop

A sail switch is a good idea too. However, I wanted to keep the safety measure I put in place internal to the generator so I can quickly and easily remove the generator from the box without much hassle. With this set up, all I have to do is connect a flexible exhaust pipe to a muffler extension I added to the generator and plug in an attachment plug to the generator receptacle once it's running and has output.

This will be easier to see when I post another video.

Here's a link to the temperature switch I used. I tried to wire it directly to the 12V output from the generator, but it didn't work cause the power gets cut off before the engine shuts completely off. This caused the generator to nearly die then keep reving back up once the 12V output stopped. I ended up using a 9V battery wired to the temp switch to supply the power and it turned out to be enough to run the switch. I just remove the access panel from the generator and remove the battery when I am not using the box. This is not an ideal set up, but it will serve my purpose fine for as little as I will actually use it.
1 Single Channel Thermal Relay Control Sensor Module Temperature Switch DC 12V | eBay

[Blackhat6mike]

Why not solar? For about a $1,500, you can have 400 watts of panels, 40 amp controller and two 115 amp hr batteries added to what you have now and a 2,500 watt inverter for 115 VAC.
If noise is a big issue and sun is not a problem where you camp, then solar is the way to go. I went down this same road with generators. Gas, noise, maintenance, securing unit, having to load/unload gen, etc. A friend showed me his setup on his hunting cabin and that sold me. Once done, it's done. IMHO

[Ryno22980]

Originally Posted by Blackhat6mike

Why not solar? For about a $1,500, you can have 400 watts of panels, 40 amp controller and two 115 amp hr batteries added to what you have now and a 2,500 watt inverter for 115 VAC.
If noise is a big issue and sun is not a problem where you camp, then solar is the way to go. I went down this same road with generators. Gas, noise, maintenance, securing unit, having to load/unload gen, etc. A friend showed me his setup on his hunting cabin and that sold me. Once done, it's done. IMHO

Where we camp, it's surrounded by tall woods. Not enough sunlight, especially in late fall in Wisconsin. I also like to reheat the previous meals leftovers in the microwave rather than cook all the time. Would take a pretty big and expensive inverter to run the microwave.

[Ryno22980]

Originally Posted by Blackhat6mike

Why not solar? For about a $1,500, you can have 400 watts of panels, 40 amp controller and two 115 amp hr batteries added to what you have now and a 2,500 watt inverter for 115 VAC.
If noise is a big issue and sun is not a problem where you camp, then solar is the way to go. I went down this same road with generators. Gas, noise, maintenance, securing unit, having to load/unload gen, etc. A friend showed me his setup on his hunting cabin and that sold me. Once done, it's done. IMHO

Sorry Mike, I read your post too fast and didn't realize you addressed the inverter in your post. I'm all for solar, but $1500 would be hard to justify for my usage. I use the TT during the summer with the family about 5-6 other times. Every other time other than fall hunting, I have shore power. If I boondocked all the time, then definitely worth it.

[Ryno22980]

Here's the promised video:

https://youtube.com/watch?v=78OWGVdDRXo

[Blackhat6mike]

Originally Posted by Ryno22980

Sorry Mike, I read your post too fast and didn't realize you addressed the inverter in your post. I'm all for solar, but $1500 would be hard to justify for my usage. I use the TT during the summer with the family about 5-6 other times. Every other time other than fall hunting, I have shore power. If I boondocked all the time, then definitely worth it.

Roger that, it's not for everybody. I figured in the gas, oil, time spent loading and unloading [I'm 70 years old], securing gen, handling the gas cans and it fit my bill. Go camping and have FUN!signhavefun: