Frank wrote:
>
> An engineer says designing a system that needs no additional
> heat input can't be done...Amory says it's possible, and even if it
> fails it will get close.
> Both seem to agree that high R, high mass, and high efficiency windows ( R
> 11?) are major parts of solution.
>
> It does not matter where the heat comes from for a radiant heat
system...but > does seem to require a lot of mechanical devices like heat
exchangers, storage
> tanks, manifolds, zone controls etc. to work well.
The assumption here is that you should design a house to work automatically
with no effort from the occupant. Perhaps that is possible, but using
mechanical devices to accomplish that only requires someone, often not the
occupant, to build and repair with the system when needed and, most
importantly, does not get us any closer to living within the limits of our
environment (raw materials, pollution, fossil fuels, industrial society,
etc.). I have heard a lot of negative comments about night time insulating
window covers (in various shapes and styles) because "no one will actually
use them consistently enough to make a difference." I don't think that
is productive thinking. It would be easy to create an "R 11" window with
an insulating cover, but very difficult to create one that is only glass
and high tech coatings and gases. Most people will open and close a window
as needed; open and close curtains as needed (usually for privacy); put on
a sweater or turn up the thermostat; sit in the sun; etc. So why wouldn't
people close insulating covers on the windows at night, or cold days in
unused rooms? With this simple change in habits you wouldn't need to buy
such high tech windows at undoubtedly outrageous prices. In fact, with a
little flexibility you could probably completely avoid an unsustainable,
expensive, and hard to maintain high tech heating system.
> Like you I am not too big on parts buried in concrete...but I'm told it
can be
> designed so that no connections are buried. Further you need some method of
> distributing the solar gain and it seems that a radiant floor system allows
> you to do that .
We did not burry any connections; they are continuous loops with
connections in an accessible spot. I highly recommend this. But there is
no guarantee that the tubing itself will last for 50 years, or 10 for that
matter. As with any new product, it's always a guess. Water damage in the
event of a system failure and difficulty of access to repair it are the
main draw backs. Any system that uses water has the first risk. Trombe
walls and the old Roman (and Korean and Chinese) system of air ducts under
a massive floor seems rather safe to me. Heating water is more efficient
than heating air, but air is a lot more forgiving when things go wrong.
The masonry stoves that are often incorporated into the interior walls are
also worth thinking about, perhaps even integrated.
> Everyone likes concept of masonry stoves...but have you seen the
prices.GRR!
> and it seems to require a good deal of skill and expertise to build
properly.
> I saw one fellow that estimated a cost for a chimney to be $10,000.
Again, sounds like a good career move to me. : )
> Lord there are so many considerations to weigh. Just wish there were
> DEFINITIVE well proven DESIGNS!
I hear you. I guess it's not much of a priority to use less and use it well.
> I'd also like to make the house smaller, but am having a hard time
balancing
> comfort, design, feeling of spaciousness that we like. I hate the cramped
> feeling you get in many small homes, the sacrifices/inconveniences you must
> make every day for lack of well planned space.
Well planned space is the key, not total square footage. Designed well,
even a small room does not feel cramped. My biggest conclusion after
designing and building our house is to build as small and as simple as
possible. And keep in mind that some of those sacrifices/inconveniences
are worth the lower mortgage, energy efficiency, easy of maintenance, lower
impact on the environment, etc.
Eric:
