Firman Generator Outdoor Box Build, reduces noise by 20dB!

Firman Generator Outdoor Box build. Reduces Generator Noise by over 20dB!
Generator - www.costco.com/firman-7500w-r...
Suncast box - www.acehardware.com/departmen...
Rockwool - www.grainger.com/product/ROXU...
Exhaust Fan - www.amazon.com/dp/B089CZG8PG?...
Exhaust Tip - www.amazon.com/dp/B07HGK4MV4?...
Exhaust Adapter - www.amazon.com/dp/B07HBD8BRJ?...
Firman NG hose - firmanpowerequipment.com/prod...
Rubber Mat - www.tractorsupply.com/tsc/pro...
all was bought on sale or discount. happy to answer any questions.

[@scottwolff228]

Bleed the gas line a till you smell gas then try starting with Half choke. If you just hooked up the gas line it was full of air not Natural Gas

[@gsftom]

Quietest I have seen and pretty simple, too.good work!

[@Truckboy383]

Great idea sir!

[@ammogiant824]

Fyi I own the same unit. When starting on NG, start with the choke on and then start it and it will start than stall. Then take the choke off and then restart, and it will fire up.

[@bujin5455]

Well done!

[@e.vasquez9946]

Good job brother. Thanks for posting

[@practicallyfrugal]

You are welcome, did my fall start up this past weekend ran quiet like a champ

[@bobpage6]

Thanks for the info on the fan I have the same generator, cabinet and muffler extenti0n

[@practicallyfrugal]

I will say if you are in a warm climate you will either want to not have the baffle boxes or a higher flowing fan as it gets warm when it is 90 out

[@sailingyemaya9781]

Works good

[@felixyoutuber]

I have the same unit from Costco. After a couple months, I started to notice that it was faster to get hotter than before and I found out there is a hot draft of air right above the exhaust vent although I have a vent extension installed. Are you able to confirm this hot air or is my unit potentially broken?

[@DukeEvolution]

You have to use the choke even on natural gas. Play with it while starting and it should start right up.

[@practicallyfrugal]

I realized that after, thanks, have only ran it a handful of times as I have been working on the build, I do plan to change the oil after I have ran it for some time as recommended

[@ChuckMorton]

@@practicallyfrugal We ran ours on LP and interestingly it never started with the choke engaged per instructions. I wonder if I have a badly built carb or this is normal for LP. The shed seems like a good Idea as I have a couple of Batts of Rockwool leftover from getting my gas fireplace insert up to code.

[@toddjones2554]

How did you attach the exterior sound boxes

[@HeartCannotFawn]

thanks for sharing your build, great work! did you use rockwool mainly for sound deadening? or for other purpose? I see bolts and washers on the Rockwool on the inside but I don't see bolts coming through the walls of the shed on the outside, so I am very curious how the bolts in the rockwool is attached to the walls of the shed.

[@practicallyfrugal]

Rockwool is there as it deadens sound and does not burn easily it has a very high melting point so it can take the heat of the engine. I use bolts with a large washer screwed into the plastic just enough to keep the rockwool in place without going thru the plastic. As while the rockwool will stay in place with friction, it will move with vibration. I used the 4" version of the rockwool in our house between the first and second floor when we did a remodel to cut down on sound transfer between the first and second floors as we have a typical early 70's colonial.

[@theodorepalmer3167]

Overall, I think you built a good quiet generator enclosure. I have a few questions. What size is the generator? How is the electrical output routed? I definitely like the baffle boxes for air intake and exhaust. Nice touch. 👍

[@practicallyfrugal]

Generator is 7500-5500 watts running depending on the fuel used. I just route the gas and electrical cable between the lid and side, the rockwool makes a good deal around it

[@dimitrin101]

Where did you source the 1" rockwool comfortboard insulation? I cannot seem to find any locally.

[@practicallyfrugal]

Grainger at the time, but don't see it on their website. This site has it, seems a bit pricey though. www.acoustimac.com/roxul-rb6-2in?PMax/Insulation/2023&hsa_acc=4716037441&hsa_cam=17880814997&hsa_grp=&hsa_ad=&hsa_src=x&hsa_tgt=&hsa_kw=&hsa_mt=&hsa_net=adwords&hsa_ver=3&gclid=Cj0KCQjw8NilBhDOARIsAHzpbLB0Nac4i8ZQnns1L0VPlmFaYo-hwWlK7W_lJWVMthmAZyFycH8vrPIaAjizEALw_wcB

[@mobettaspice]

I’m surprised that battery didn’t die on the start ups.

[@dedhead9322]

out of curiosity, is that a window beneath your exhaust pipe? 04:43

[@practicallyfrugal]

yes, but is completely sealed/caulked shut, in fact that whole side of the basement along the sill plate has been air sealed, but yes I do understand the potential concerns with CO

[@toasterj3643]

i was thinking the same , they tell you to run your generator 15 ft from house but when people use a generator box most people put it up against house never understood that - good job on box

[@cayrick]

Undersized fan! Inside the box should be no more than 10-15F than ambient. Also neat looking job but exposed mineral wool can cause itchy skin.

[@bobpage6]

I am in New Orleans and it gets hot I may put a small input fan I have a picture but could not find a place to add it I would like to add a WIFI temperature monitor

[@johnwicked9301]

That exhaust fan is installed on the wrong side of the box my friend.

[@sciencesymphony9766]

Do you think that the cooling of the generator is really sufficient ? Some years ago, I did something similar with a generator, but he becomes much too hot after a while !!!

[@practicallyfrugal]

I think it is adequate for a cool day operation, not a warm summer, I think if doing again I would go a size up on the fan to move some more air

[@davidschipsi1316]

I would fashion a duct from outside the box right to the engine and one for the power alternator. This way it always has the coolest air possible. Without this even though there is some ventilation the generator is getting recirculating hot air that will get too hot to cool properly. The engine and alternator have there own fans to do this.

[@practicallyfrugal]

@@davidschipsi1316 I attempted to do that as the intake is on the left backside of the box feeding right behind the generator. I did my fall test run this past weekend and it was much cooler in the box as it was 50 degrees outside. On a 80+ day the top would need to be cracked a bit for more airflow. Upgrading the exhaust fan maybe an option as well. This was my first iteration, and tried to conceal the baffle boxes as much as possible. Other versions I saw either had great airflow, but no sound proofing or great sound proofing with poor airflow or poor asthetics.

[@toddjones2554]

What size screws did you use to attach the rockwool

[@practicallyfrugal]

Was either 1 1/4 or 1 1/2"

[@toddjones2554]

@@practicallyfrugal i love it. Gonna copy you and build mine

[@practicallyfrugal]

@@toddjones2554 the one thing I would change is the material of the baffle boxes or at least the quality of the paint. I had used thin board that ended up delaminating from water. I had used a spray paint on it and at a minimum probably should have used some oil base enamel paint. In the spring I plan to attempt a rebuild with sheetmetal that is lined with the rockwool as it will be less bulky than the wood boxes I built.

[@bobpage6]

Where did you get the fan and how much

[@practicallyfrugal]

Amazon was $42.99, now $47.50 with coupon. I added my own cord/plug from an old appliance iPower 7 Inch Shutter Exhaust Fan Aluminum,High Speed, 1680 RPM, 760 CFM, Silver a.co/d/inwF7iZ

[@ChuckMorton]

Nice! Do you happen to know the WC pressure at your house?

[@practicallyfrugal]

Referring to barometric pressure outside?

[@ChuckMorton]

@@practicallyfrugal the NG pressure (usually in inches of Water Column). Its usually about 6-9 inches

[@practicallyfrugal]

@@ChuckMorton I do not know NG gas pressure. Never had a need to measure it, I would need a meter to do so

[@ChuckMorton]

@@practicallyfrugal depending on the provided pressure and line constriction, the generator may not make full load.

[@practicallyfrugal]

@@ChuckMorton I will for a inexpensive pressure meter. Line to the house feeds a 70kBTU 95afue furnace, use it to have a 40 gallon gas water heater as well, but was swapped for a 50gallon Rheem hybrid heat pump water heater about 13 months ago

[@jamesmisner9582]

Careful of overheating!

[@practicallyfrugal]

It is possible if the top is not slightly cracked open but I have since taken these elaborate boxes off the back as the wood rotted, not as quiet but air flows freely, need to design something out of metal paint it and and the same sound deadening in a smoother flowing design

[@REALBanannaman]

How are your temperatures looking?

[@practicallyfrugal]

I have not had to run it yet, but with it being 30 degrees out, I think I will retest it

[@camperbum]

Mine has a choke, and almost starts right up...

[@practicallyfrugal]

Yah I realized that after, and you are right starts right up if using it.

[@diamondfirst9956]

Everything ok guys, he just forgot to turn the NG valve on

[@justhear1726]

Get a spare starter