----- Original Message -----
From: <EeeMCee@cs.com>
To: <vintage-race-digest@autox.team.net>
Sent: Thursday, January 06, 2000 12:09 AM
Subject: Re: Shop Floor heating
Michael,
Floor heating was done with both copper and steel piping in years past, the
oldest I've come across was a pig barn built in 1910. My father was in the
truck leasing business and built several shops in the late sixties and early
seventies with steel pipe in the floor. The mechanics always raved about
how nice it was to work on warm floors that dried quickly. The problem was
that both steel and copper react with salts in the concrete and eventually
the pipe fails.
Polyethylene pipe does not have the susceptibility to corrossion, but can't
stand much temperature. Pex is cross-linked polyethylene (PE-X) and was
developed by Wirsbo back in the late sixties. IT can stand rated
temperature and pressures to 200 degreesF and 80 psi. Cross-linking is the
only difference between coal and diamonds. It has to do with manipulating
the chemical structure of the polymer. Our long term testing indicates a
life span for pex in concrete of over a hundred years. We haven't found the
point at which it will fail, so we really believe it will last for the life
of the concrete slab.
Yes, these systems are slow to respond. Typically you would set your
thermostat and leave it at one temperature. The mass of the slab is like a
huge flywheel: once you get it to temperaure (or speed) it requires very
little energy to sustain the process. Usually these systems heat for 40%
less energy than with a forced-air system. Insulating under the slab,
something that probably was not done on your copper system, helps modern
systems, too. Incidentally, setting temperatures up and down on a daily
basis produces very little if any fuel savings in any tyoe of system. Think
of it in terms of running down the highway at a steady 55 (I know, I can't
drive 55) as opposed to accelerating to 75, then coasting down to 35, then
speeding up to 75, etc. Which produces the best fuel mileage?
The really nice part of these systems is the comfort they provide. I could
go on for several hours about the benefits and proper design of hydronic
radiant floor systems (after all, that's how I support my racing habit), but
it's so easy, effective, and inexpensive to do that I tell anyone, if you're
pouring a concrete slab you really should put the tubing in the floor when
you have the chance.
By the way, my first such job in 1981 was a commercial greenhouse in central
Pennsylvania that used the waste heat from a power plant (coal-fired, but
nuclear would work) run through tubing in the slab for heating. 115 degree
water would heat the 4-acre greenhouse down to an outdoor temperature of
about 5 degrees. Greenhouses are obviously the worst type of building to
heat, since the skin of the structure is two layers of 6-mil polyethylene
over an aluminum framework.
John Lehman
Ohio Regional Office
J.C. Mottinger Associates, Inc.
Manufacturers' Representatives
1008 Crook St., Grafton, OH 44044
Ph: (440) 926-2404 Fax (440 ) 926-1194
JELehman@ix.netcom.com www.Wirsbo.com
> In a message dated 01/05/2000 9:07:24 PM Pacific Standard Time, EeeMCee
> writes:
>
> << << Very often this only requires a water heater and pex tubing 12"
> on center imbedded in the concrete. Even better than lying on carpet
> scraps! >>
>
> John: you MUST live in the sunbelt! It probably would take a nuclear
reactor
> in the rest of the world!
> I had a house in California with this and it was nice but you had to
always
> keep the place warm otherwise it takes about a day to overcome the thermal
> inherit of the floor.
> What is Pex tubing? The builder of my house used copper which went and
> leaked in some years!
> Michael
> Dolphin Porsche F 1 >>
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