Real Estate Forum

On Mon, 07 Jan 2008 11:24:44 -0500, HVAC Guy <HVAC@Guy.com> wrote:

>Bob Pietrangelo wrote:
> 
>
>Remember the following:
>
>1) this is a two-stage (or double-unit) furnace.  I will dig-up the
>model number and post it later.  This unit was sized and installed in
>1981 to heat only the upper floor of a small commercial office
>building.  The upper floor is about 3000 sq. ft.
>
>2) The second unit rarely, or never, comes on during the day, and I
>believe it only comes on when the thermostat calls for heat in the
>morning when the setpoint changes from 63f to 71f.
>
>3) I have turned down the burners on the first unit (the second unit
>has a manifold gas valve that is not adjustable).
>
>4) there is no barrier inside the furnace (from side-to-side) in the
>burner galley area, so the 2 intake vent lines (4" diam) can
>essentially feed both sets of burners (when they're both in use) or
>feed air to only the first set of burners (when only one side of the
>furnace is running).
>
>What this means is that you need to consider a situation where 4
>burners running at reduced gas pressure are drawing primary and
>secondary combustion air from two 4" flex lines (combined area = 25 sq
>in.) equivalent to a square duct 5" x 5".
> 
>
>Like I said, I will post the furnace model number and see if there's
>any info on the internet about it, like BTU output.
> 
>
>(I'm adding "?" to your quotes because you don't seem to be putting
>them in yourself)
>
>The furnace has only 1 motor (I think it's 3/4 hp) and it drives both
>blower fans.
>
>And like I said, the second furnace rarely comes on when I'm there to
>watch.  I would bet that it only comes on during the initial heat
>ramp-up in the morning.
> 
>
>Yes.
> 
>
>No idea.  I don't have a meter to measure this pressure, and I don't
>particularly care to do it anyways.
> 
>
>In the furnace room right beside this double furnace is a single
>furnace (whisper heat, electronic ignition, motorized damper gating
>the primary air intake).  This is for the lower level of the
>building.  It's flue is being fed into the 12" stack mentioned above.
>That furnace is not in use this heating season.
> 
>
>I don't know.
> 
>
>Prior to my modification, the furnace room was very cold in the winter
>because it had essentally an open vent directly to the outside.  By
>closing that vent, and ducting air from it directly to the furnace
>cabinet, the room is no longer cold.
>
>And in it's original state, the draft air would have been cold anyways
>because as I said the room was cold.  Not only that, but bottom of the
>furnace cabinet was raised about 1" above the floor, allowing the fan
>to pull some amount of cold air directly from the furnace room.
>Internally, the bottom of the furnace was not closed or sealed.
> 
>
>I don't see Mr. Storm's posts because he posts from Road Runner.  The
>news server I use automatically cancels posts from Road Runner because
>a lot of spam and flood posting have come from Road Runner over the
>past few months.  By all accounts, Road Runner is an irresponsible
>operator when it comes to usenet.
>
>I also don't see posts from:
>
>.p.jm@see_my_sig_for_address.com
>nicksans...@ece.villanova.edu
>
>because their posts are also being deleted by the news server I use
>(I'm not sure of the reason why in those cases).
> 
>
>The "scientific" answer is that I am seeking to limit the amount of
>cold-air infiltration into the building, and I'm achieving that by
>ducting primary combustion and draft air directly to the furnace
>cabinet thereby creating a closed combustion system similar to (I
>assume) the design technique used by high efficiency furnaces today.
>
>And by reducing the heat output of the burners, I am essentially
>modulating the furnace so that I am capturing a higher percentage of
>heat and increasing the furnace run-time duty-cycle (again I believe
>the same techniques are used in modern high efficiency furnaces).
> 
>
>The climate that I experience is similar to Chicago, Detroit,
>Cleveland, Buffalo or Toronto.

Keep babbling GayGuy. You altered it and you'll be on the hook for it
when it malfunctions. The best part is you've posted it on here as a
permanent record in the newsgroups for all the world to see.
Especially those evil lawyers. muhahahaha
Bubba

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