From: John De Armond
Newsgroups: alt.hvac,alt.energy,alt.energy.homepower,alt.home.repair,
	alt.energy.renewable
Subject: Re: Asking for Recommendations for New  HVAC in a Row Home
Date: Tue, 03 Apr 2007 05:23:55 -0400
Message-ID: <rs64139p9nkrtpq4jsj67n60atjmlim54b@4ax.com>

On Mon, 2 Apr 2007 21:22:23 -0500, <kjpro @ usenet.com> wrote:

>
>"Mike" <1234@yahoo.com> wrote in message
>news:%xiQh.3469$i93.2052@trnddc05...
>
>> several posters recommended a system that includes a high efficiency heat
>> pump, well the contracotrs here are not sold on heat pumps I din't know if
>> they don't have experience w/ the new HPs.

I agree with the contractors here.  Baltimore is not a favorable
climate for heat pumping.  Especially given the electric rate there.

>
>
>> both units are 80% because they claim they can't vent properly an higher
>> efficiency units.

Totally disagree.  All that's needed is a flue booster fan.  Maybe
$50-100 extra.  The high efficiency units invariably contain induced
draft fans so the flue is forced and doesn't rely on convection.  Only
on really long flue runs would a booster be needed.

Assuming there's no irrational code against it (who knows in that
area), wall exit flues can be used.  This device looks like a little
white mushroom on the side of your wall that both exhausts the flue
gas and intakes fresh air.  I used them for a multiple high efficiency
gas boiler changeout in PA in an apartment building I owned in the
early 80s.  Loved 'em.  I have pictures if you need 'em to refute any
flak you might get from the contractor.


>
>
>By the two above comments...
>
>You better KEEP LOOKING!!!!!!!!!
>

One last comment.  I'm sure glad I live down here.  That's about twice
the going rate here.  I doubt either contractor is gouging - that just
reflects the extra cost of the overbearing amount of government y'all
tolerate.  BTDT, glad to be back South again.

John

From: John De Armond
Newsgroups: alt.hvac,alt.energy,alt.energy.homepower,alt.home.repair,
	alt.energy.renewable
Subject: Re: Asking for Recommendations for New  HVAC in a Row Home
Date: Tue, 03 Apr 2007 21:55:21 -0400
Message-ID: <g11613t4iu7kc6ca7v4s7csfbh3i9cgatk@4ax.com>

On Tue, 03 Apr 2007 23:38:23 GMT, "Mike" <1234@yahoo.com> wrote:

>

>> Totally disagree.  All that's needed is a flue booster fan.  Maybe
>> $50-100 extra.  The high efficiency units invariably contain induced
>> draft fans so the flue is forced and doesn't rely on convection.  Only
>> on really long flue runs would a booster be needed.
>
>They claim the problem is venting because they mostly vent consendation (?)
>and they way my house is built it'll have to vent into the alleyt a throuh
>fare or
>my cement deck which is a walkway.

Neither is a problem.  The highest efficiency furnaces are condensing
furnaces.  That is, the flue gas is cooled to the point that the
moisture generated by combustion is condensed out.  The furnace has a
little drain tube that feeds this condensate typically to the same
condensate pump that the AC uses.  The flue gas is cool enough that
PVC is used for the exhaust run.  What comes out outside is a slightly
warm, humid low velocity stream of air, almost always odorless.  There
is certainly no burn or fire hazard.  Basically, it can be exhausted
pretty much anywhere except directly into an air intake that feeds
habitable spaces because of the ever-so-slight risk of CO.

Need to find another contractor, I'm afraid.

John

From: John De Armond
Newsgroups: alt.hvac,alt.energy,alt.energy.homepower,alt.home.repair,
	alt.energy.renewable
Subject: Re: Asking for Recommendations for New  HVAC in a Row Home
Date: Tue, 03 Apr 2007 23:23:35 -0400
Message-ID: <l266131uiasa73uh025g8chuiuugk00r6o@4ax.com>

On Wed, 04 Apr 2007 02:27:39 GMT, "Mike" <1234@yahoo.com> wrote:

>
>"Neon John" <no@never.com> wrote in message

>>
>> Neither is a problem.  The highest efficiency furnaces are condensing
>> furnaces.  That is, the flue gas is cooled to the point that the
>> moisture generated by combustion is condensed out.  The furnace has a
>> little drain tube that feeds this condensate typically to the same
>> condensate pump that the AC uses.  The flue gas is cool enough that
>> PVC is used for the exhaust run.  What comes out outside is a slightly
>> warm, humid low velocity stream of air, almost always odorless.  There
>> is certainly no burn or fire hazard.  Basically, it can be exhausted
>> pretty much anywhere except directly into an air intake that feeds
>> habitable spaces because of the ever-so-slight risk of CO.
>>
>> Need to find another contractor, I'm afraid.
>>
>they said building codes don't permit vent over walkways and alleys because
>it freezes and creates a safety hazard.  they also told me its cool to the
>touch and vents using pvc.
>

That's what the counterflow exhaust vent is for.  This vent consists
of two concentric pipes.  The inner one carries the flue gas and the
outer one carries fresh air for combustion.  The cool incoming air
cools the flue gas down to the ambient outside temperature, condensing
out the moisture which, if the flue is installed with the proper
slope, flows back inward to a low point drain.  The exiting flue gas
is at or near the outside ambient temperature and dew point so there
is nothing to condense and freeze.  The outside part of the vent is
plastic that is thermally non-conductive and of low specific heat
which means that it quickly warms to whatever the exhaust temperature
is, precluding condensing and freezing.

An additional benefit of this type of vent is that since no combustion
air is taken from the living spaces, no additional drafts are caused.
No more cold feet when the furnace kicks on.

I don't know Baltimore's code but I'd be very surprised to find that
the use of counterflow exhaust vents is banned.  More usual is the
contractor claiming something is against the code to get out of doing
something he doesn't want to do.  Hard for a customer to argue with
"the code" (that he probably knows only slightly better than the
customer.)

I STILL suggest talking to other contractors.  Methinks you're being
BSed.

John