From: John De Armond
Newsgroups: rec.outdoors.rv-travel
Subject: Re: No Freeze Water Hose
Date: Thu, 29 Nov 2007 13:32:12 -0500
Message-ID: <jl0uk3da7961fmrq3gnh2iqvg622j5r8ss@4ax.com>

On Thu, 29 Nov 2007 12:30:32 GMT, "C_L_R_D" <cathylee260@nojunkhotmail.com> wrote:

>We have a water heater which floats around the top of the water and keeps it
>ice free, but my problem is the water line that comes from the cement floor
>in the barn freezes solid into the cement. Using a heat gun takes 10-20
>minutes twice a day. My hubby uses hot water poured over and in still takes
>awhile. He says he has tried heat tape (before marriage) but it still froze
>in the ground. I have heard stories of the heat tape catching fire under
>mobile homes, and I am scared it would burn the barn down.
>Do you all think heat tape is safe is there a right way or wrong way to use
>it?
>Have you heard any stories of heat tape catching fire?

There are two main kinds of heat tape.  Thermostatically controlled and
self-regulating.  The thermostatically controlled tape contains a wire heating
element and a thermostat that turns it on just above freezing and turns it off a
little warmer.  This is the cheap stuff that the big box stores sell.  It has a big
dongle on the cord where it hooks to the tape.

This kind of tape WILL catch fire if it is improperly insulated.  The tape puts out a
constant amount of heat per foot.  If that heat is prevented from escaping by
insulation, the tape will eventually melt and burn.  I had a short piece smoke but
not burn in my walk-in freezer's condensate line where I'd excessively insulated it.

The other type of tape is self-regulating.  It consists of typically a matrix of
carbon in plastic that is conductive.  As the matrix heats up, the plastic expands
and the carbon particles move apart, increasing the resistance and decreasing the
current.  In other words, the hotter the tape gets, the less heat it makes.  This
happens all along the tape so that if one section is insulated and another isn't,
they both run at about the same temperature.

This type will not overheat and will not catch on fire.  It is more expensive than
the simple heater tape but is well worth it.  This type of heater is what is used in
that No-Freeze hose.

>
>My solution was to put in a freeze proof yard hydrant but he said he would
>have to dig up the cement floor 4 ft, I wondered if one could dig the hole
>outside next to the barn where the water line comes in and install it under
>the floor that way, or even leave it outside... but I'd still have to carry
>16 buckets of water everyday...free workout I guess. :)

The freeze-proof-ness of that type of hydrant is defeated if a hose is attached.  The
way it works is that the valve is placed below the frost level.  A long rod runs from
the handle through the vertical pipe to the valve.  A small hole above the valve
drains the vertical pipe when the valve is closed.  It can't freeze because there is
no water in the pipe above ground.

An attached hose prevents the vertical pipe from draining.  This pipe and the hose
will freeze like any other.  A backflow preventer will usually let in enough air to
drain the vertical tube but it won't prevent the hose from freezing.

I haven't seen your installation, of course, but if enough insulation is used over
self-regulating heat tape then the pipe should not freeze in the slab, assuming the
pipe goes straight down to below the frost line.  If the pipe stays above the frost
line on the horizontal run then it's gonna freeze :-(  Not much you can do other than
to re-route it.

John