Hybrid Car – More Fun with Less Gas

Re: Not home(turn off A/C), home( then turn on A/C) question? - Page 3

register ::  Login Password  :: Lost Password?
Posted by Rod Speed on July 25, 2004, 7:30 pm

Yeah, but then so do you |-)

Wrong. There's plenty of automatic doors right
thruout the first world, tho not usually used for that.

Not vital when you are primarily just using the shutters to give the
windows a high R value when you need that for the windows.

And its not hard to make them seal well if you need that.

Depends on whether you are talking about fully commercial
systems or stuff you make. It isnt really valid to use the price
of the commercial systems when you are making the rest of
the house yourself and not counting the labor costs etc.

Dont need luck, just a bit of capability.

Posted by Timm Simpkins on July 26, 2004, 1:18 am


Okay, I just looked at your numbers again.  You were talking about something
different.  In your calculations, and with the bed made of the materials you
were talking about, the bed would take 7 days to heat and therefore 7 days
to cool.

Actually it was your 160 hour bed.


Well, I haven't moved a bed for almost 20 years.  Now that I think about it,
the bed I was thinking of was an old roll away bed my family had when I was
a kid.  It had no metal in it at all.  I've just done some looking around at
mattress sites and they show cross sections of mattresses sometimes.  It
appears they can be made many different ways, from all cotton to air cores,
foam and cotton.  It appears the most common mattress is a steel spring core
with 3/4 to 2 inches of foam and cotton.  Then there are some made with
semirigid foam cores with similar covering.  Others are made with 100% foam
of different densities with fabric over the top.  All should beat your
figures considerably.

As far as numbers go, I tend to be on Nickola Tesla's side.  It's much
better to examine what happens in the real world than to rely on numbers.
How about sticking your bed outside for 2 days in 100+ degree heat and try
and sleep on it.  I guarantee you won't get it to cool down in 3 hours in 70
degree heat.  I've had my bed in that kind of heat and I can tell you it
didn't cool down in less than 2 days, much less than 2 hours.



I was wrong.  According to the ASHRA Handbook (American Society of Heating,
Refrigerating and Air-conditioning Engineers) the thermal mass Factor of
pine is 2.76.  So I was off by a little, but not by near as much as you are.




That's kind of funny since I can get a garage door opener to seal more than
well enough to do what I need, and I'm pretty sure those have been around
more than 30 years.  It would amaze me if you couldn't get a motor that can
crush a human being to properly close shutters.  That's actually too much
power anyway.  If I balance the shutters well, I could use relatively low
torque stepper motors to do the job and if necessary, which it won't be, I
could use sensors connected to a PIC microcontroller to determine how well
the door had closed and compensate.


If you insulate the mass, you don't get the benefit of the solar heat.  Snow
would be a good insulator in the winter, but that isn't quite beneficial to
passive solar heating.

It very well could be.  If I wanted to spend millions of dollars, I could
probably design a home that was much more efficient than the one I propose.
It comes down to cost vs. gain.

South facing windows with open shutters when the sun is out and closed
shutters when the sun is down.  The sun shines directly on the floor (Solar
Slab) and heats it.  That heat is transferred throughout the floor.

Only if they are not insulated at night.


I guess you haven't heard of convection.  When the air in the house gets
cold, it goes down, and the warm air rises.  Cold is attracted to heat and
heat attracted to cold, so the cold air will be attracted to the solar slab
where it will in turn be heated.

A floor doesn't need a fan though.  Another thing that you get if you make
your walls with that design is the problem of how to shield them from the
sun on warm days.  You don't want to store heat in the summer.

It's not necessary to keep the room exactly at any temperature.  The idea
isn't to totally eradicate the need for any temperature control, but to
substantially lessen that need.

Yes, if you don't have a furnace or air conditioner to make up for the

Almost every house has ductwork that is exposed to the air in the house, yet
nobody seems much worried that you can't easily clean that.  Like I said
earlier, there would be a 6 mil poly vapor barrier between the blocks and
the sand/gravel bed it lays on.  That 6 mil vapor barrier is a well accepted
way of keeping moisture out of the inside your exterior walls, where there
is plenty of air space.  That also means that the air space under there
wouldn't be any more humid than the air in the house.  That same air that
circulates througout your interior, uninsulated sheetrock and stud walls and
never seems to cause a problem.

This is not to say it wouldn't be a haven for mice and insects, but we've
all seen Jerry's mouse hole in the wall.  The archway might be a human
invention, but mice have lived in any space that will shelter them forever.
The same with insects.  They are a fact of life.  I don't hear of anyone
tearing their walls down to get rid of nests.  Likewise, I don't think that
a floor needs to be ripped up for the same reasons.

How would you get the heat to them in the winter and keep it away from them
in the summer?

That's why the shutters are so important.

maintenance house available today?

Warm air rises, but when that warm air rises, where does the cool air it
displaces go?  Convection again.

But if you have to worry about things getting too hot in the summer time, a
sunspace is generally an inhibition to cooling.

Yes, and yet there was no electricity to run fans.  How many slaves did it
take with palm leaves to circulate that air through the floors, or was it
moved with convection?

I don't doubt there are better materials that could be used to store the
heat, but water probably isn't the best to construct a floor from.

The slab does not use a fan.

If you're talking about exterior walls, how do you keep the house from
overheating in the summer?  If you're talking about interior walls, how do
you get the heat to them in the winter?  With a solar slab, that is taken
into account.







You have cited many things he states in his book without saying what is
wrong with those statements.  One of those citations says on page 17 he

As you can see, the reduction in solar benefit increases exponentially as
you rotate the home's orientation away from true south.

Technically that is true, but he goes on to state:

Within 20 degrees or so of true south, the cost of variation in the lost
solar benefit is minimal, which allows some latitude in placing the house on
a site that presents obstacles such as slopes and outcroppings.

If you look at his numbers there, at 22 1/2 degrees rotated east or west,
you only get 92% of the solar benefit.  This is within reasonable specs for
what he is trying to accomplish.  That gives a homeowner about 45 degrees to
work with.  If you are saying that he is wrong, then what is wrong about it.
You went through the whole book quoting things that I assume you think are
wrong, but there was only one thing you gave any argument about.

What was wrong about those other statements?

Posted by Max on July 25, 2004, 3:02 pm

If i use a candle to light it, will the heat buildup kill me before the
carbon monoxide?


was played by maxwell monningh  8-p

This Thread
Bookmark this thread:
  • Subject
  • Author
  • Date
please rate this thread