[VAC] Re: Balsa core flooring

[bob basques <bob.basques@xxxxxxxxxxxxxxxxxxx>]

Sounds like a pretty even split with the PRO's vs the CON's

> True that routing would allow more versatility in tubing placement, but
> one would have to watch how "versatile" tubing placement was if the
> finish layer required screw fasteners that would penetrate the foam...
> Then its handy to have the tubing in predictable places.

I've thought about that too, I hereby retract my previous statements along these
lines, although I would reserve the right to have multiple standard spacing

> Dissipation or spreader plates are good for the heating function, and
> rotten for the structural function. They need to be adhered to the foam
> and to the top skin because this assembly converts bending moment to
> shear between them.

I stopped today at my local Heating Contractor (to pick up parts for my new home
heating system) and asked some questions related to these radiant floor mail
posts.

He showed me a product that come pre assembled in 1/2" form with the dissipater
plate, aluminum, stapled (similar to the gussets in a roof truss) to the 1/2"
press board on either side of an opening that accepts 5/16" tubing. He mentioned
that this was typically used for retro-fitting a bath area. the spacing was
close, around 4", for the tubing. I would imagine that 5/16" tubing could be
bent fairly sharply.

> Radiant heating is most effective when it can radiate to the occupants.
> That's how its efficient. It can't radiate from under the cabinets, and
> you sure don't need to be adding heat under the refrigerator...

In a retro-fit (applying radiant floor over existing) I agree with you. I still
like the idea of some heat going into the cabinets, may be wasteful, but so be
it. If it make you any happier, you have convinced me not to put as much under
the cabinets as I would have before we traded posts   :-)

> I don't know about a heat source. Needs a pump too. I suppose a sureflow
> water pump will handle the temperature. There are versions that handle
> farm chemicals decently. Looking at the prices for electric tankless
> water heaters, I'm inclined to use a 2 or 6 gallon water heater tank for
> that application.

I think that with the small amount of water I would try out the smaller version,
2 gal., especially with the 5/16" tubing.

> 5100 btu (1500 watts) is nearly enough for my Caravel, but something
> larger would need more to be comfortable.

I may be able to get away with less BTU's than other with my Excella, I have the
double insulated glass versions of the windows. I wouldn't think I would need
more than 10,000 BTU's for the 30' trailer.

> The 1500 watt element standard
> in a 2 or 6 gallon electric water heater could be replaced by something
> larger. There needs to be an expansion chamber on the heating loop to
> allow for the changes of water volume when hot.

I found what looked like about a 1 quart version in a catalog at the
contractor's today

> Its not like it can push
> back into the municipal water line when it expands in the home
> situation.

I wonder if two or three air chambers might not work for the expansion just
throw a pressure pop off inline, and everything would be good to go. The whole
thing including the electric heating would only take up the space of a small
suitcase.

I don't believe that this package would weight much much over 45-50 lb., add in
the weight of the new structural floor, and I don't think that I would have a
problem with the extra weight. I could lose some weight by removing the current
forced air furnace.

bobb