Generator room ventilation

[waterice]

Hello everyone,

I was looking for requirements on ventilating a generator room. Does it have to only be naturally ventilated?

I've looked at NFPA 110 (2008) but it seems ambiguous.

 

[chicopee]

Do an engine search. By just typing "indoor generator fresh air requirements" I got multiple hits.

 

[willard3]

You will need both combustion and cooling air which will be cataloged by generator manufacturers.

 

[waterice]

Well, for the cooling air, can it be coming from a cooling coil?

Because one of the concerns is that if we're using a cooling coil and if it failed at the same time that the generator was required, then you'd end up with inadequate cooling and so we're trying to see if there is any code requirement mandating only the use of OA dampers to condition the generator room.

 

[chicopee]

When you say cooling coil, are you referring to a radiator being part of the generator? As stated above, manufacturers' catalog will provide you all the info.

 

[waterice]

No, the radiator itself is mounted on the roof. But we'd still need to handle the heat load from the generator. I'll look up the manufacturer's specs and see what they have to say.

Thanks chicopee and willard3 for your advice.

 

[MintJulep]

NFPA 110 (2016) consistently uses the word "ventilation" when discussing cooling of the generator room.

The definitions section of NFPA 110 says for words that aren't specifically defined in the standard use the common dictionary definition.

The common dictionary definition for "ventilation" is "provide fresh air from outside".

So, yes it has to be only natural ventilation.

 

[waterice]

I was thinking on the same lines. Thanks MintJulep!

 

[aungkyawtun]

I am from marine sector and always use ISO8861

 

[cry22]

No - wrong interpretation of the word Ventilation.

ventilation does not mean natural ventilation in our trade, you should not go by what the dictionary says, but by how your industry defines the word ventilation, i.e. as defined by IMC, not by the webster.

IMC defines Ventilation as follows:
Ventilation is defined as the Natural or Mechanical process of supplying air.
Ventilation Air is defined as the portion of any supply air that comes from outside plus any recirculated air.

Use exhaust fan with Outdoor intake with filters, dampers, thermostat, the classic ventilation, account for combustion air. That's it.

 

[MintJulep]

Sorry cry22, but you're not right.

NFPA 110 explicitly tells you to look it up in the dictionary.

Where terms are not defined in this chapter or within another chapter they shall be defined using their ordinarily accepted meanings within the context in which they are used. Merriam-Webster's Collegiate Dictionary, 11th edition shall be the source for the ordinarily accepted meaning.

 

[cry22]

Mint,
Nope, allow me to disagree.

NFPA 110 is not one of the referenced standards in IMC. We design per code. The code is IMC, not NFPA 110.
NFPA is a guideline unless referenced by IMC.

and I agree with IMC for the Ventilation definition, not with NFPA 110.

AND, if you read your quoted text correctly, it says "ordinarily accepted meanings within the context they are used" - What NFPA is saying in the quoted text is that when NO specific definition is known, then you rely on the dictionary. But there is a Known definition as defined in IMC.

I love it, we talk like lawyers.

 

[317069]

Look at the generator manufacturer literature, they should refer to the installation requirement.

 

[cry22]

Here is a source for details and schedules for most of young engineers that I am sure will find helpful

http://www.cfm.va.gov/til/sdetail.asp

check the emergency gen set detail from the same site below, this one has a radiator indoor, just edit to suit the remote radiator application. The remote radiator application is actually much simpler.

http://www.cfm.va.gov/til/sDetail/Div23HVACSteam/SD230923-07.pdf

317069: gen set manufacturers do not issue installation details, they just issue air flow requirements.

 

[317069]

Cry 22
air flow of what?

 

[cry22]

317
air flow for radiator (when radiator part of gen set), combustion air flow, alternator cooling air flow.

 

[317069]

cr.
Young engineers are happy with grandpa gift.
also, didn't Caterpillar give you installation details such as clearances around generator, ambient temperature, room temperature and condition if it was for indoor application.

 

[dbill74]

Have to agree with Cry22 regarding the definitions and that IMC is the governing code.
IMC defines "Ventilation" as "The natural or mechanical process of supplying conditioned or unconditioned air to, or removing such air from, any space."
And "Ventilation Air" as "That portion of supply air that comes from the outside (outdoors), plus any recirculated air that has been treated to maintain the desired quality of air within a designated space."
Furthermore, IMC does not specifically define mechanical ventilation, but does define "Natural Ventilation" as "The movement of air into and out of a space through intentionally provided openings, such as windows and doors, or through nonpowered ventilators."
If Natural Ventilation is ventilation using nonpowered means, then Mechanical Ventilation would be the use of fans to force the ventilation air through the designated space.

Doing a word search through NFPA 110, I do not see anywhere specifying that the ventilation air to be either natural or mechanical. Thus I would interpret NFPA 110 to mean that the ventilation air can be either natural or mechanical in nature.

Going back to Sidd20's OP and his question

Does it have to only be naturally ventilated?

my answer would be no, it does not have to be only naturally ventilated.

 

[317069]

Why IMC is governing code?

 

[dbill74]

In the US, at least, each state determines a code to which they want buildings constructed to. For most states this is ICC's building codes including IMC. Select states such as Florida and New York have their own building code which are based on IMC. DOD and other US governmental agencies use IMC with select changes. I have yet to see any of these modified versions of IMC change definitions.