[Strawbale] Sub Floor Radiant Heating

[Shody Ryon]

--- Ilan Ungar <adrihalut at gmail.com> wrote:

> OK, just to sum this up... So the reason one would
> turn down a wealth of
> heat during the entire heating season, any day, all
> day, all for FREE- 100%
> solar energy... is the initial cost of the system,
> or are there other
> reasons???

I am looking for some writing about this, here is some
related info and I will see if I can find the other
think that answers more directly,

I was wondering about thermal storage (TS) in this
way, because dry earth is a good thermal mass (TM)
medium which generally available to land owners, why
not make a large area a TS area, the larger the
better. 
Can earth be used to store cool and does the earth
need to be dry like for storing heat?
I am just an internet researcher in regards to these
questions and what I think is build the system that
you want to build.

I would like a system that is easy to operate, uses
renewable energy, preferable solar and has multiple
functions, heats and cools. Costs least in money
effort and complexity, accomplishes the goals with the
least input, built with free or low cost recycled
material, requires least effort, is healthy to the
inhabitance and the world. 

I have not full explored "air through pipes in the
ground" systems, but some people have had mold
problems in the pipes. I think this has mainly been
for cooling “earth tubes” but I do not know, because I
became interested in the thermal loft system using low
thermal mass in the house driven by thermal siphoning
and a solar assisted heat pump.

Water can be used instead of air through tubes. There
is a draw back to this but I can't think of it right
now. One I can think of is pipes break. Another is it
sounds simple, but there is going to be a lot of
systems; thermal collection, pumping, thermal transfer
from collection fluid to heating system, domestic hot
water, energy to pump water, possible slow response to
warm people from time it is turned on. These systems
are all required in a air heating system but is easier
to deal with and mistakes and breakdowns are more
forgiving, systems cost less. 

I think earth tubes may be the same as geothermal
which I associated with heat pumps. Geothermal heat
pumps take advantage of the fact that the temperature
underground, in a pond or ? is constant, high mass and
is in a range that refrigeration units can extract
concentrated heat or cold, where as AGS (see:
greenershelter.com) uses large amounts of charged dry
earth as thermal mass to eliminate the need for heat
pumps for heating.

I have heard that some geothermal heat pumps have been
changing the temperature of the ground requiring them
to either be used year round, to some degree, in order
to stabilize the temperature by adding the opposite
temperature back (stated crudely) or have 2 wells to
let the one recover temperature while the other one is
used, etc.

Laren states that his system is over 5 times as
efficient as an electric resistance heater. My first
thought is wouldn't use an electric resistance heater
long term unless I was run by a batteries charged with
PV panels, so I have nothing to compare it to. 

Here is a little about geothermal from Laren:

Q.... To save more, invest in a solar assisted ground
loop heat pump with hydronic underfloor heat.

A...In most cases having both Solar and ground source
for the same job, would be overkill, and the payback
would not be nearly as good as when just one of them
was used, because doing both requires a very high
initial investment.

Q...Go one better, just use solar, with a large enough
tank to hold enough heated water to cover cloudy days

A...There is yet another option. Instead of using an
expensive
ground loop as the source for the heat pump backup
heating,
use the Solar heat storage as its source. When the
storage is
too cool for using its heat directly, it is still much
warmer than
the ground, so the heat pump will be able to function
at an
even higher COP (Coefficient Of Performance) than a
ground
source system. Of course, the cost of running the heat
pump
to the Solar storage will be only a tiny fraction of
the cost of
a ground loop. Back in the 1970s and 80s there were a
few
overly complicated and very expensive Solar heat pump
systems built. But, heat pumps, in general, were not
very
efficient back then. Over the decades, since then,
heat pump
technology has progressed, and electric prices have
stayed
relatively flat compared to other heating fuels. So,
at this time,
the marriage of low temperature Solar collection, and
a heat
pump, is highly cost effective. It also removes the
need for
any fossil fuels, with their monthly base rates, and
leaky
flues, that continually pull warm air out of your
house.

I am presently starting to use small heat pumps
with my sunspace houses, and their heat storage lofts.
I have two such houses under construction, right now.
Basically how it works, is that when the heat storage
drops to a temperature that is too cool to either
effi-
-ciently, or comfortably blow enough air, or pump
enough water to warm the living space (which just
happens to be typical air conditioning temperatures),
the heat pump simply "air conditions" the heat
storage,
with its heat exhaust tube running to the living
space.
With a small 14,000 to 15,000BTU unit, costing less
than $400, it can get a COP of over five (five times
as much heat, per kWh, as electric resistance heating,
including the electricity to power fan heat
distribution).
That is ground source heat pump efficiency, at only
a tiny fraction of the initial cost. It also
effectively
just about doubles the Solar heat storage capacity,
while allowing the sunspace (or air type Solar panels)
to collect at much lower temperatures, therefore
more efficiently.

Q.... I use a regular heat pump and wood stove

A..You could take advantage of a simple heat storage
for
your wood heat, and a small, low-cost, heat pump/AC
located in the heat storage area, will offer the
option of
it heating the house for a much longer time, between
fires, or when you are not at home.

Q...I live in the frozen north, and would love to find
> an alternative way to heat my house, all electric.

A..Rather than usng hydronic Solar panels, you can
build
a simple low-mass, single glazed, sunspace. It need
not
be super insulated, because it is only warm when the
sun
is heating it. You can build it like a porch. Or, you
could
use simple vertical wall air type collectors. Either
way,
if you want a larger percentage of Solar heating, you
will
need a heat storage. I suggest using bottles of water,
which store a lot of heat for their weight, and act as
their
own heat exchangers. In the loft is about the best
place
for such a heat storage, because it does not take up
floor
area, and the sunspace heat will rise to it, without
the need
of an air mover, or dampers, or automatic controls.
When
the living space needs some heat, you just bring a
little of
the warm attic air down, with a small fan or water
pump.
When the loft air is not warm enough, you "air
condition"
the attic with a portable air conditioner. These
litttle units
have an exhaust hose to blow the heat to outdoors in
summer. In winter, when using it to heat the house and
"cool" the heat storage, it blows its hot air down
into the
living space. The result is that you get over five
times as
much heat from the electricity that it uses, as you
would
get from an electric resistance heater.

-Laren Corie-
Natural Solar Building Designs, Since 1975
www.LarenCorie.com

-LittleHouses-
http://groups.yahoo.com/group/LittleHouses

-Energy Self-Sufficiency Newsletter- Free at
www.rebelwolf.com

-WoodGas- Power from Wood.
http://groups.yahoo.com/group/WoodGas

-Refrigerator
Alternatives-http://groups.yahoo.com/group/RefrigeratorAlternatives
 yes, I did inter-change heatsink and thermal



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