Heatsource with low energy consumption.

[Moojundai]

Thanks for the great calculations, they look rather enlifting.

As the 15 degrees often are the worst case scenario, and they are only short
bursts.

Often the temperature swings between +5 and -5 degrees C. And as far as i
can se from your calculations then this could work with very small margins.

Insulation mats on the floor, and maybe covering the windows (2 windows
aprox 1½x1 metres) as well in months with frost.

The door into the room leeds to a similar insulated room, witch must be a
plus?

No need for growing the plants in frost time, but survival would be nice )

Would heating a mass of water (150 litres) be a good or a bad thing in this
scenario?

I'm preparing a website as I go by, to dokument my experiments, dont know if
it is of interest for anybody?

 

[Moojundai]

"daestrom" <daestrom@NO_SPAM_HEREtwcny.rr.com> skrev i en meddelelse

IF his -15C is the overnight low (warmer during day) *AND* he is able to
cover the windows at night with some type of thermal blanket, then it sounds
like the 200W should be fine.

Sounds nice!

I think he was looking for whether to use the 200W to circulate air through
a ground tube or some such to try to bring up some air from the ground.
Since he's just trying to stay above freezing, air warmed from a few large
pipes buried well below the frost-line might be more than enough. Just use
the 200W to run some circulating fans. Problem with that is the amount of
excavation he would need for a whole heating season's ground tubing is
probably more than the cost of using the most expensive commercial energy he
has available to him.

I don't think that would be easy to install (concrete floor), but the system
would probably work fine.
What depth does it need? 90cm?

 

[Moojundai]

What you are trying to heat is commonly known in English-speaking
countries as an outBUILDING, not an outHOUSE, otherwise known as a
privy.

???? My father (that owns the "outbuilding") is a brittish citizen, and he
has always called it an outhouse?

But never mind, we've been throu that )

I've seen these "solar thermal collectors" mentioned a few times. What are
they?

Fire is not an option. The buildings are from 1790 and partly wood
(outside), the insurance compagny would go balistic if they found out.
Besides the building is left unatended for periods of time.

How much energy does black velvet or black paint absorb when met by
sunlight?

 

[Moojundai]

Don't get discouraged! Unless you are in very cold climes, it's quite
do-able.

What is being ignored is heat absorbed during the day, and temperature
differential. The temperature in the outbuilding will not suddenly drop to
the outside temperature. It's more like a slow leak. On many days, it may
take until well after midnight until any heating is needed. Then, the
temperature rise needed will not be that great. It takes only a little bit
of heat to raise the temperature in such a small area by 5 Deg. In many
cases, that may be all you need. There will be extended cold spells with no
sun, for which you will have to plan. The foundation and ground will act as
a heat sink, so it's important to keep the floor warm and keep the pots on
the floor. Installing a false ceiling of foam insulation or plastic sheet
can greatly reduce wasted heat.

Sounds very optimistic.

 

[daestrom]

"daestrom" <daestrom@NO_SPAM_HEREtwcny.rr.com> skrev i en meddelelse



Sounds nice! energy

I don't think that would be easy to install (concrete floor), but the system
would probably work fine.
What depth does it need? 90cm?

Run from underground outside, bringing it above grade to come into side of
building at base of wall. Insulate the pipe where it is above ground
outside of course.

As to depth, it would depend on how deep the 'frost-line' is. Here in NY
USA, that's at least 4 ft (~1m). But if your winters are milder, you might
get away with less. But to use this method all winter long, you might need
quite a length of piping. I don't have precise calcs, but it could be +30m
of ~10cm diameter piping on the order of 1m deep.

But considering the numbers that 'Ecnerwal' ran, you might just as easily
use the 200W with resistance heating. If the temperature warms up more
during the day, you might also add some thermal storage to help 'ride out'
the cold dips in temperature at night. This would make it so the
temperature drops slower when it gets cold out. If you can slow it down
enough, the temperature won't reach freezing before morning. Nothing fancy,
just a couple of large water jugs (~10 L a piece). Of course, if you have a
prolonged cold spell and *they* freeze, you might have a real mess on your
hands (split open the jug).

Guess it depends on how much money, how badly you need to avoid freezing,
how bad you think those cold winter nights can get. What are you currently
doing?

daestrom

 

[[email protected]]

Well, I'm sure you know the difference. Please respect it.

In point of fact, it was just a typo...

I'd say it's a "thinko." Recall "that pestilent fellow, the critical reader,
who demands that the words used actually make sense"? Jim Augustyn's Return
of the Solar Cat book (I just bought 35 copies) has another E.B. White quote:

A cat sunning himself in the doorway of a barn
knows all about solar energy. Why can't man learn?

Nick _should_ have been able to figure that out...

Sure, and you as well, on second glance, but lots of alt.energy.homepower
readers still don't know the difference between power and energy! Why
perpetuate this confusion? It's more than a "wrong choice of words,"
since appropriate units give important clues in solving problems.

Nick

It's a snap to save energy in this country. As soon as more people
become involved in the basic math of heat transfer and get a gut-level,
as well as intellectual, grasp on how a house works, solution after
solution will appear.
Tom Smith, 1980

 

[Bob Adkins]

Sounds very optimistic.

Sounds like experience. Nature abhors very low and very high temps.

Bob