Main Air Vents

HenryT · December 2009

I am planning to vent my mains and have 1 question before making the purchase on the vents.

I have a finished basement with main hidden above dropped ceilings. I have located the end of main and want to vent it with a bigger vent. However, due to height clearance area I may not be able to add a Gorton #2. I was looking a Pex Supply and saw a Hoffman 75.

Are these comparable to Gorton? I know the overwhelming choic would be Gorton due to its venting capacity, but am I sacrificing a lot with a Hoffman 75?

What if I use the menorah approach and attached 2-3 of these Hoffmans?

Any inputs would be much apprecaited and thanks in advance.

Wishing Dan and everyone of you wall addicts a very prosperous new year!

jpf321 · December 2009

about 1/2

Hoffman 75 has about 50% the venting power of the G#2. FYI, a G#1 has roughly 25%-30% of the G#2.

jpf

HenryT · December 2009

Thanks a lot

Thanks!

I think ill just do a menorah setting up with 2 hoffman and a 2 G#1.

Pex supply does not have exact sizing on hoffman. Does anyone know the height for it?

jpf321 · December 2009

hoffman size

Here is a link to the hoffman data sheet for the #75:

http://www.hoffmanspecialty.com/pdf/hs900/HS900-steamall.pdf

I do not know the height for the G#1 .. perhaps someone else can provide that data.

I think your post implies that you will install 2pcs of Hoffman #75 and 2pcs of G#1, is this correct?

jpf

HenryT · December 2009

Thanks again

Yes, i plan to put 4 vents becuase you can never overvent.

why do you see a downside in this set up?

David Nadle · December 2009

Technically, you can overvent

You can "overvent" if you add too many vents for the the capacity of a pipe. For example, two Gorton #2's on a 1/2" menorah overwhelm the venting capacity of the pipe itself. It's not going to hurt anything; it's just a waste of money.

Personally I think any combination of Hoffmans or Gortons will work just fine.

A Gorton #1 is a little over 3" tall.

jpf321 · December 2009

no downside...

i don't see a downside .. the wording of your post was a bit confusing "a 2 G#1" .. i just wanted to be sure you were meaning "2pcs of G#1".

mel rowe · December 2009

Main air vents

How much actual room do you have to install the vent?

HenryT · December 2009

hey Mel.

Hi Mel. i know i still owe you update on downfire. I have enlisted another pro off this forum and will let you know how the appt went.

back to the question: Well, the on the end of main tapping, i need to add elbows and nipples & tees to make the menorah, which will cut into my overall clearance. Even with that set up, i have about 3"-4". So settign up a menorah with multiple G # 1 or Hoffmans is probably the best solution for me in order for me to get the same venting as a G#2.

I have another question regarding main venting i am asking for a buddy.He just purchased a home with 1 pipe steam heating. His end of main runs from basement into the first floor strangely enough. on this pipe, there is a hoffman vent there (1/8 NPT) fitting. and it HISSES like NO TOMORROW when there is a call for heat. it is LOUD. i am planning on replacing this for him but the 1/8 tapping can be an issue,. Can i put a nipple that increases that tapping to 1/4 or 1/2 NPT and add a Gorton on that line.

I have no clue why the end of main is there. its sitting in the corner and runs about 5' into the first floor. Is this the Main or is it a riser meant for a removed radiator?

jpf321 · December 2009

venting capacity of 1/8th hole

you can install fittings to properly install a reasonable vent in that 1/8th tap .. but keep in mind that it will only support the same capacity of 1pc G#2 or less .. anything more that 1pc G#2 is wasted money because you can't vent any faster through that size opening .. this is equivalent to Mr. Nadle's comment about overventing ..

FYI .. 1/2" NPT has capacity to vent roughly 2pcs G#2 + 1pc G#1 anything more on 1/2" is wasted money.

HenryT · December 2009

JPF321

Thanks again.

I will buy bushing and coupling to "upsize" that hole. Do you think it will still hiss being that we are sort of make shifting a small hole to fit a big vent.

jpf321 · December 2009

in theory...

the hissing is a function of an overworked vent (to small an opening on vent) .. with a larger vent you should have less/no hiss...but then there's also this: http://www.heatinghelp.com/forum-thread/128591/Leaking-Gorton-2

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