# Generator installed indoors



## amptech (Sep 21, 2007)

I have a homeowner customer who wants a Generac 20kw NG fueled air-cooled generator installed inside his attached garage. I instinctively said no, it wasn't allowed. He insists on the install. I called the building inspector and the fire marshal and they both refuse to say whether it is allowed or not. I call Generac and they say absolutely not, it is not listed or approved for installation inside a building or structure. This customer says I either install it in the garage or he will hire someone who will. Has anyone else had a request like this?


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## B4T (Feb 10, 2009)

Nope.. no can do..:no::no:

The generator must be installed outside and (5) feet from any window.. door.. vent.. or opening into the house.. 

There are no exceptions..


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## Wireman191 (Aug 28, 2011)

Let someone else get sued! Your business is not worth this one customer.:no:


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## Big John (May 23, 2010)

What I know about this I could write on a matchbook, but it seems very strange to me that we can put all manner of wood, oil, and gas fueled appliances in a home but can't legally install a generator indoors? 

I understand it may have to be a specially fitted generator, and certainly someone competent would have to exhaust it, but if the guy's money is green I would definitely look for a legal solution.

-John


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## wildleg (Apr 12, 2009)

I recently serviced an indoor installation. the local state highway has an indoor cat (its getting old, and insanely loud lol). but it's in an indoor commercial building with fire suppression etc. if his garage was 2 hr rated, had a FA, I could see it, but I don't know the building codes for it. Sounds like you need to have a sit down with your ahj.


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## Magnettica (Jan 23, 2007)

A shed over the genny would be nice. Then maybe build some 3' paver walls around it. Maybe a put it on a concrete slab wouldn't hurt either. It'd make a cool hangout area for all your electrical buddies.


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## B4T (Feb 10, 2009)

Big John said:


> What I know about this I could write on a matchbook, but it seems very strange to me that we can put all manner of wood, oil, and gas fueled appliances in a home but can't legally install a generator indoors?
> 
> I understand it may have to be a specially fitted generator, and certainly someone competent would have to exhaust it, but if the guy's money is green I would definitely look for a legal solution.
> 
> -John


There are no exhaust systems that are approved for indoor use when it comes to your standard free standing generator..

There are also a bunch of NFPA standards you have to satisfy so you are not liable if someone dies..

Last year a guy died here when the CO gas went in through the dryer vent that was loose on back of the dryer.. 

People find wacky ways of dying all the time..


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## Bulldog1 (Oct 21, 2011)

B4T said:


> Nope.. no can do..:no::no:
> 
> The generator must be installed outside and (5) feet from any window.. door.. vent.. or opening into the house..
> 
> There are no exceptions..



Kohler says 8 feet from any intake, window or door. Vents are not mentioned or I don't remember reading vents. You would never aim the exhaust toward the structure anyway.


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## B4T (Feb 10, 2009)

Generac lists NFPA 37, 54, 58, and 70 standards to follow..

You can get them in the library..


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## B4T (Feb 10, 2009)

Bulldog1 said:


> Kohler says 8 feet from any intake, window or door. Vents are not mentioned or I don't remember reading vents. You would never aim the exhaust toward the structure anyway.


Houses built with a crawl space have fresh air vents for that space.. that is what they are talking about..

Some boiler rooms also have fresh air intake vents you have to watch for..


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## Bulldog1 (Oct 21, 2011)

B4T said:


> Houses built with a crawl space have fresh air vents for that space.. that is what they are talking about..
> 
> Some boiler rooms also have fresh air intake vents you have to watch for..


I was told a vent is not an intake by the inspectors here. A gas log air intake is an example of an intake. But I agree it is no different from a window or door.


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## amptech (Sep 21, 2007)

From what I understand from the tech support person at Generac, their air-cooled stationary models don't have a single exhaust outlet. There are 3 exhaust points that help create a drafting effect around the engine to help facilitate cooling circulation. This would make it impossible to directly vent the exhaust. Models that are listed/approved for indoor installation are liquid cooled with single point exhaust and would still require a fire protection system such as sprinklers or Ansul in the immediate area.


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## amptech (Sep 21, 2007)

Bulldog1 said:


> I was told a vent is not an intake by the inspectors here. A gas log air intake is an example of an intake. But I agree it is no different from a window or door.


The installation manual lists a foundation vent among those openings requiring clearance.


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## Bulldog1 (Oct 21, 2011)

amptech said:


> The installation manual lists a foundation vent among those openings requiring clearance.


I do not remember seeing vent in the Kohler instructions. I could be wrong. I will look in the morning. They have diagrams with placement options in the manual.


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## RIVETER (Sep 26, 2009)

amptech said:


> I have a homeowner customer who wants a Generac 20kw NG fueled air-cooled generator installed inside his attached garage. I instinctively said no, it wasn't allowed. He insists on the install. I called the building inspector and the fire marshal and they both refuse to say whether it is allowed or not. I call Generac and they say absolutely not, it is not listed or approved for installation inside a building or structure. This customer says I either install it in the garage or he will hire someone who will. Has anyone else had a request like this?


Why do you think that you should not do it as the customer specs? He IS the customer.


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## Wireman191 (Aug 28, 2011)

RIVETER said:


> Why do you think that you should not do it as the customer specs? He IS the customer.


 :blink:


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## B4T (Feb 10, 2009)

RIVETER said:


> Why do you think that you should not do it as the customer specs? He IS the customer.


Are you nuts.. since when does a customer get away with installing a product illegally..:blink::blink:

The customer is off the hook..but the installer gets nailed to the wall..


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## B4T (Feb 10, 2009)

What happens if the customer sells his house a year later and the new family has no clue about generator safety..

The whole family dies.. who becomes liable..


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## mattsilkwood (Sep 21, 2008)

Maybe a residential thing. I've seen quite a few generators installed inside on industrial and institutional jobs.


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## amptech (Sep 21, 2007)

RIVETER said:


> Why do you think that you should not do it as the customer specs? He IS the customer.


Because I spoke with my insurance agent this AM about the situation and was told that if the installation did not comply with the manufacturers instructions or local/state codes they would not cover any damage claims related to the installation. Enough said. He can find someone else or have me install it outdoors.


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## Wireman191 (Aug 28, 2011)

mattsilkwood said:


> Maybe a residential thing. I've seen quite a few generators installed inside on industrial and institutional jobs.


 Yes, But they have automatic louvers, and fans to get rid of the bad air. Houses are going to be a wayyyyyy different animal.


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## B4T (Feb 10, 2009)

mattsilkwood said:


> Maybe a residential thing. I've seen quite a few generators installed inside on industrial and institutional jobs.


They are designed for that purpose and meet all the standards for indoor gas operated equipment..


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## RIVETER (Sep 26, 2009)

amptech said:


> Because I spoke with my insurance agent this AM about the situation and was told that if the installation did not comply with the manufacturers instructions or local/state codes they would not cover any damage claims related to the installation. Enough said. He can find someone else or have me install it outdoors.


Now, that's what I'm talkin' about. The customer is not always right.


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## macmikeman (Jan 23, 2007)

I've seen em in basement parking garages (floor being 4 or 5 ft below grade, not like a real basement found on the mainland), for high rise hotels here. But those had good ventilation screens that allowed plenty of the jet stream trade winds to circulate.


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## SparkyfromArky85 (Jun 26, 2011)

I am a Generac tech and when I was at the two week training they found a YouTube video of a previous student (tech) that installed one indoors and they were in our class talking about pulling his tech license. Not that he still wouldn't install them. But they are strict on that when it comes to safety.


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## Dennis Alwon (May 9, 2009)

I have only seen inside generators when they build a separate structure around the generator. Never seen one inside a dwelling unit.


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## A Little Short (Nov 11, 2010)

It's only been a month or so ago that at a biker rally not too far from me 4 people died from carbon monoxide from a generator. They were in their camper and the genny was outside, but too close to the vents and it entered the vents and killed them in their sleep. No way would I install one indoors, no matter how much I made on the installation.


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## Shockdoc (Mar 4, 2010)

I have dealt with many Onan and kohler installs inside garages and utility rooms. You will be in a whole other ballgame of generators, non enclosed, hardpipe exhaust to exterior, It is permissible .


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## amptech (Sep 21, 2007)

Shockdoc said:


> I have dealt with many Onan and kohler installs inside garages and utility rooms. You will be in a whole other ballgame of generators, non enclosed, hardpipe exhaust to exterior, It is permissible .


Not permissible with any air-cooled generator I have found currently on the market.


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## Shockdoc (Mar 4, 2010)

amptech said:


> Not permissible with any air-cooled generator I have found currently on the market.


These were all water cooled open units from a 4 cyl onan to a 6 cyl cat diesel. My ex boss used to install and run service contracts so every winter during the slow season was oil change and tune up grease monkey season.


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## joethemechanic (Sep 21, 2011)

There are a whole lot of these air cooled units installed in Philly police stations


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## Modern Castle Inc. (Nov 9, 2011)

Carbon Monoxide is an odorless, colorless gas that will kill you, ask him if he would leave his car running in the garage?

Check out this puppy...
http://www.gentran.net/eshop/genshed-shelter.asp


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## kbsparky (Sep 20, 2007)

Does he have a death wish? You might want to give him a few newspaper clippings of instances where folks died from such installations ....


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## nitro71 (Sep 17, 2009)

If the customer insists just do the electrical inside. He can get the generator, vent it and plug it in.


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## ilikepez (Mar 24, 2011)

http://www.nj.com/news/index.ssf/2011/11/elderly_holland_twp_couple_app.html

tldr; elderly couple killed by generator in enclosed garage...

edit: and that was five days ago. I wouldn't do it. Hell send him that link if you want.


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## RIVETER (Sep 26, 2009)

I know that...I was being the Devil's advocate.


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## BBQ (Nov 16, 2010)

amptech said:


> I have a homeowner customer who wants a Generac 20kw NG fueled air-cooled generator installed inside his attached garage. I instinctively said no, it wasn't allowed.


Without a doubt in my mind you can install generators inside homes and garages.




> He insists on the install.



Not a bad thing, $$$



> I called the building inspector and the fire marshal and they both refuse to say whether it is allowed or not.



I think that is wise on their part without seeing details about the job.



> I call Generac and they say absolutely not, it is not listed or approved for installation inside a building or structure.


Now that, .... if I confirmed that with the labeling on the unit, that would stop me from moving ahead. 

I would offer to find the customer a generator that could be installed inside but there is no way at all I would do it if the generator is not designed for it.



> This customer says I either install it in the garage or he will hire someone who will.


I would have to let this one go, I can't do the wrong thing just to get the jobs. 





> Has anyone else had a request like this?


When I was an apprentice we set one up in garage, the exhaust was routed out with factory supplied parts, muffler, thimble, (A thimble is used to pass the hot exhaust pipe through the side of the building)


In another very large home we installed a large generator in the basement, this was a water cooled unit and duct work was run to supply the radiator with outside air.

The exhaust left the basement low underground ran out about 100' under the yard and into some trees and into the side of a burred cement manhole section. From above all you saw was a round metal grate.


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## B4T (Feb 10, 2009)

BBQ said:


> Without a doubt in my mind you can install generators inside homes and garages.


None of the Generac generators I have seen come with a "tail pipe" that you can vent to the outdoors like a gas boiler.. they all have louvers on the side or pipes sticking up in the air like a Mack truck..

I am sure you have seen other brands designed for indoor use.. just not "Genercrap" as you like to say.. :laughing:


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## BBQ (Nov 16, 2010)

B4T said:


> just not "Genercrap" as you like to say.. :laughing:


I was good, a long post and I did not even go there. :laughing:


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## McClary’s Electrical (Feb 21, 2009)

BBQ said:


> Without a doubt in my mind you can install generators inside homes and garages.
> 
> Not a bad thing, $$$
> 
> ...


How can a generator indoors comply with nfpa 37 clearances?


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## B4T (Feb 10, 2009)

nitro71 said:


> If the customer insists just do the electrical inside. He can get the generator, vent it and plug it in.


That is a really bad idea.. you never want to get involved with any jobs where someone will eventually die from your work.. :no:


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## McClary’s Electrical (Feb 21, 2009)

Bulldog1 said:


> Kohler says 8 feet from any intake, window or door. Vents are not mentioned or I don't remember reading vents. You would never aim the exhaust toward the structure anyway.


A crawlspace vent would be an intake.


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## BBQ (Nov 16, 2010)

mcclary's electrical said:


> How can a generator indoors comply with nfpa 37 clearances?


Not knowing what it says I can't say but these are inspected jobs.


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## McClary’s Electrical (Feb 21, 2009)

BBQ said:


> Not knowing what it says I can't say but these are inspected jobs.


Well, an inspector can't enforce nfpa 37 unless it's referenced in the installation manual, so it would pass inspection, and would still be wrong and a liability.


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## Bulldog1 (Oct 21, 2011)

mcclary's electrical said:


> A crawlspace vent would be an intake.



You are correct. It was listed in the instructions but not the diagram. Most installs we do have conditioned crawl spaces and the vents are blocked off.


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## BBQ (Nov 16, 2010)

mcclary's electrical said:


> so it would pass inspection, and would still be wrong and a liability.


And I would bet it is not 'wrong' there are literally thousands of indoor generator installations. We put one or two in each supermarket we wire. 

Most are natural gas but we have put some large diesels inside as well.


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## McClary’s Electrical (Feb 21, 2009)

BBQ said:


> And I would bet it is not 'wrong' there are literally thousands of indoor generator installations. We put one or two in each supermarket we wire.
> 
> Most are natural gas but we have put some large diesels inside as well.


In a masonry enclosure maybe. If not it's wrong.


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## B4T (Feb 10, 2009)

BBQ said:


> And I would bet it is not 'wrong' there are literally thousands of indoor generator installations. We put one or two in each supermarket we wire.
> 
> Most are natural gas but we have put some large diesels inside as well.


You have to separate residential from commercial units since it is apples and oranges.. :thumbsup:


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## BBQ (Nov 16, 2010)

mcclary's electrical said:


> In a masonry enclosure maybe. If not it's wrong.


I am sorry that is simply BS, you will have to show me this code.


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## Bulldog1 (Oct 21, 2011)

BBQ said:


> And I would bet it is not 'wrong' there are literally thousands of indoor generator installations. We put one or two in each supermarket we wire.
> 
> Most are natural gas but we have put some large diesels inside as well.


I would think if the manufacture says not for indoor use in the instructions you would be violating Article 110.


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## BBQ (Nov 16, 2010)

B4T said:


> You have to separate residential from commercial units since it is apples and oranges.. :thumbsup:


Read the thread before posting, we have installed a large unit in a single family homes basement as well. :thumbsup:


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## B4T (Feb 10, 2009)

mcclary's electrical said:


> In a masonry enclosure maybe. If not it's wrong.


An enclosure has nothing to do with it.. since you have to be in there servicing the unit..

Must be designed for "Indoor Use".. is a better fit..


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## BBQ (Nov 16, 2010)

Bulldog1 said:


> I would think if the manufacture says not for indoor use in the instructions you would be violating Article 110.


Does anyone read the damn thread before posting?:laughing:

I already made it very clear in post 32 I would not violate the listing and labeling.


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## Bulldog1 (Oct 21, 2011)

BBQ said:


> Does anyone read the damn thread before posting?:laughing:
> 
> I already made it very clear in post 32 I would not violate the listing and labeling.



I usually don't read the whole thread. My bad. :whistling2:


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## B4T (Feb 10, 2009)

BBQ said:


> Read the thread before posting, we have installed a large unit in a single family homes basement as well. :thumbsup:


But that is not a common installation like we are talking about here.. you sound like TOOL bringing a mansion into the debate.. :laughing:


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## BBQ (Nov 16, 2010)

Bulldog1 said:


> I usually don't read the whole thread. My bad. :whistling2:


It happens to all of us. :laughing:


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## jbfan (Jan 22, 2007)

Bulldog1 said:


> I usually don't read the whole thread. My bad. :whistling2:


What's this thread about anyway?:laughing:


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## BBQ (Nov 16, 2010)

B4T said:


> But that is not a common installation like we are talking about here.. you sound like TOOL bringing a mansion into the debate.. :laughing:


It was a big place, about 26,000 sq ft.

But to the code it is still just a single family dwelling built of wood and drywall. 

It was located in the same basement mechanical room with the oil fired boilers.


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## amptech (Sep 21, 2007)

BBQ said:


> It was a big place, about 26,000 sq ft.
> 
> But to the code it is still just a single family dwelling built of wood and drywall.
> 
> It was located in the same basement mechanical room with the oil fired boilers.


I am sure your installation was code-compliant. There are generators manufactured for indoor installation. The air-cooled model which was the generator in my OP is not intended for indoor installation.

The rest of my story is:
The customer got irate with me and called Generac. They proceeded to explain to him that an indoor installation of this generator was prohibited by several NFPA codes and would void the warranty with Generac. He called me back to tell me this like it would be news to me and that he was going to order the generator and transfer switch himself at Home Depot. He said it was $200.00 cheaper than the price I had quoted him to begin with. He wants me to install it outside on a concrete pad when it arrives. I didn't say I would or wouldn't. I am willing to bet he didn't order the SE rated transfer switch, which his circumstances require, or the battery kit. I think he will need to call someone else.


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## Big John (May 23, 2010)

BBQ said:


> ...It was located in the same basement mechanical room with the *oil fired boilers*.


 Exactly my point. I fail to see what makes a generator special just because it has an engine.

A screwup installing a boiler, a wood burning stove, a gas furnace are all gonna be just as deadly as a screwup with a generator.

-John


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## B4T (Feb 10, 2009)

amptech said:


> He called me back to tell me this like it would be news to me and that he was going to order the generator and transfer switch himself at Home Depot. He said it was $200.00 cheaper than the price I had quoted him to begin with. He wants me to install it outside on a concrete pad when it arrives.


Is HD going to locate the generator on the pad or drop it at curbside..

A concrete pad is a waste of money.. I install mine on a rectangular platform made out of 4" X 6" landscape ties..

It keeps it off the grass so the landscapers don't maul it with their machines and it makes changing the oil that much easier..


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## BBQ (Nov 16, 2010)

B4T said:


> A concrete pad is a waste of money.. I install mine on a rectangular platform made out of 4" X 6" landscape ties.


It would surprise me if the instructions don't require a non-combustible base.


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## B4T (Feb 10, 2009)

BBQ said:


> It would surprise me if the instructions don't require a non-combustible base.


Good point.. but they only mention a pea gravel base..


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## Bulldog1 (Oct 21, 2011)

B4T said:


> Is HD going to locate the generator on the pad or drop it at curbside..
> 
> A concrete pad is a waste of money.. I install mine on a rectangular platform made out of 4" X 6" landscape ties..
> 
> It keeps it off the grass so the landscapers don't maul it with their machines and it makes changing the oil that much easier..



Kohlers new residential line comes with a composite pad made into it. You still need 6" around it and 4ft at the exhaust end that is non combustible. I use pea gravel normally.


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## B4T (Feb 10, 2009)

Bulldog1 said:


> Kohlers new residential line comes with a composite pad made into it. You still need 6" around it and 4ft at the exhaust end that is non combustible. I use pea gravel normally.


Generac has the same setup and the design of the (2) models are almost identical..


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## Bulldog1 (Oct 21, 2011)

B4T said:


> Generac has the same setup and the design of the (2) models are almost identical..



A generac is still a generac. :whistling2::laughing:


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## B4T (Feb 10, 2009)

Bulldog1 said:


> A generac is still a generac. :whistling2::laughing:


And almost $500.00 cheaper.. :thumbup::thumbup::thumbup:


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## Bulldog1 (Oct 21, 2011)

B4T said:


> And almost $500.00 cheaper.. :thumbup::thumbup::thumbup:



And cheap is what you get for $500.00 cheaper. :whistling2: :thumbup:


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## BBQ (Nov 16, 2010)

Bulldog1 said:


> And cheap is what you get for $500.00 cheaper. :whistling2: :thumbup:


But it is wired to the home with copper so it must be good ..........:whistling2::jester:


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## amptech (Sep 21, 2007)

Big John said:


> Exactly my point. I fail to see what makes a generator special just because it has an engine.
> 
> A screwup installing a boiler, a wood burning stove, a gas furnace are all gonna be just as deadly as a screwup with a generator.
> 
> -John


NFPA 37 is a completely separate standard for combustion engines and gas turbines. They are different than straight burners and boilers.


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## green light (Oct 12, 2011)

I recently installed a 500kw cat diesel at a hospital. The gen was purchased with its own enclosure. The enclosure was built of aluminun and about 20'x10' and about 10" thick and insulated. I picked the enclosure off the back of a semi with a crane and set it right over the gen. Exaust bolts right together and your good to go. Most big gens Ive done are enclosed in a block uilding. A contractor I do work for says he installed a Generac indoors a couple of years ago. I didnt do the work. He says that generac gave him permission to do so, but they required he remove the housing. Not sure how he dealt with the exhaust, but I will ask him. I know that the install passed inspection.


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## BBQ (Nov 16, 2010)

amptech said:


> NFPA 37 is a completely separate standard for combustion engines and gas turbines. They are different than straight burners and boilers.


Different codes, hardly different in danger. 

Both burn fuel and produce poisonous gases.


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## amptech (Sep 21, 2007)

BBQ said:


> Different codes, hardly different in danger.
> 
> Both burn fuel and produce poisonous gases.


I disagree. There are different dangers to consider with an internal combustion engine. Mechanical safeguards for a gas/oil fired furnace or boiler are a lot less complex than those for a combustion engine or turbine. That is precisely why there is a separate NFPA code for them, the dangers are different.


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