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From: John De Armond
Newsgroups: sci.engr.heat-vent-ac
Subject: Re: Excessive water runoff
Date: Thu, 16 Jun 2005 15:09:42 -0400
Message-ID: <>

On Thu, 16 Jun 2005 01:49:08 GMT, "JJ" <> wrote:

>I live in Texas.  My unit stays on most of the day.  The problem I have
>is that there is so much water being drained outside.  Within a week
>I can have a small pond.  I have to relocated the drain pipe at least
>twice a month.  Is there something I could do to help this?  Is this

The unit is functioning properly but that is not particularly normal
in that apparently excessive moisture is entering your house.  To
solve the condensate problem you need to address this problem.
>The unit is a 4 ton, A-frame.  It is not mounted in the ceiling.
>The house has poor insulation.
>I change my filters at least once a month and clean my coils
>every year.
>Electric bill runs about 200 a month, but I'm not complaining.
>I just don't want a mosquito farm in my yard.

Poor insulation won't contribute to this problem per se but the lack
of a vapor barrier will.  some things to check:

Does your wall insulation have a vapor barrier.  Remove a wall outlet
cover and look inside for foil or plastic.

Does your floor have a vapor barrier and/or insulation?

If you have a crawl space, is it moist?  Do you have a vapor barrier
(plastic) over the dirt?

If you have a basement, is it moist/wet?

Are there major air paths from outside and/or the crawl space into
your house?  Unsealed holes, perhaps where a pipe or wiring had been
removed?  Sloppy construction leaving gaps in the decking or siding?

Is your house under negative pressure?  A leak in the supply ducts to
the attic or basement will cause outside air to be sucked into the
house through infiltration routes.  You can check this by cracking a
window with the unit running.  Apply smoke to the crack and see which
way it moves.  If there is significant incoming air then you need to
look for a duct leak.  Confirm that it's a duct leak and not normal
convection by turning the AC off and comparing.

To deal with the water if you can't run it to a drainage ditch or
curb, the usual solution is to dig a little cesspool.  A few feet
across, a few feet deep and filled with coarse gravel and optionally
capped with dirt.  This will retain and spread out the water until the
ground can absorb it.


You could collect it in a tank and pump it onto your roof through mist
nozzles to help reduce the heat load.  I installed such a system on my
flat tar roof, poorly insulated building using city water.  It made a
remarkable difference in the AC load and cost, even factoring in the
city water bill.


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