In alt.solar.thermal Derek Broughton wrote:
In Northern latitudes, what may be much worse for causing overheating is
large glass expanses in West windows. West windows get little to no heat
gain in Winter, but can't be shaded by overhangs in Summer.

I can picture the angles of incidence of the sun varying from winter to
summer. I have a covered walkway where I marked "north" by noting the
shadow of the support posts at solar noon on a winter day. The sun never
shines on that spot in the summertime.

How does one determine the desired eave overhang and angle? I would
imagine that different times of day could be selected for the shade needed.
Enough shade to shield the house between 10am and 3pm? On June 10th?
Those calculations I could make, with input from
http://www.gcstudio.com/suncalc.html

I have the same question about my Solar Sponge. It will be fixed to the
azimuth of one wall, but I can set it at any elevation that I like.
Presuming that it would be most useful before noon, I was going to use
suncalc over a 9am-noon period and locate the lowest average variation from
sun angle for some fixed panel angle. http://solarsponge.com

--
---
Clarence A Dold - Hidden Valley Lake, CA, USA GPS: 38.8,-122.5

wrote:

How does one determine the desired eave overhang and angle?

The max sun elevation at noon on 12 and 6/21 is 90-lat+/-23.5 degrees,
eg 26.5 and 73.5 for Phila's 40 N latitude. You might use simple geometry
to make an overhang that admits all winter sun on 12/21 and excludes all
summer sun at noon on 6/21, with some blank wall between the top of the
glass and the overhang. With more effort, you can make an overhang with
a triangular cross section that's reflective beneath and bounces more
winter sun into the window and still excludes all sun at noon on 12/21.

Nick

Mary Fisher wrote:


"Derek Broughton" wrote in message
...

It's not hard to make the
south facing windows work. You need overhangs, as pointed out, but the
angle of incidence, along with the right kind of glazing makes it
entirely possible to restrict heat gain.

The problem with that is that it cuts down light too. I prefer to shade
with curtains, which are movable.

They are - but the heat is already _inside_ by the time the light hits your
curtains, so you have potentially lost the battle already.
--
derek

"Derek Broughton" wrote in message
...
Mary Fisher wrote:


"Derek Broughton" wrote in message
...

It's not hard to make the
south facing windows work. You need overhangs, as pointed out, but the
angle of incidence, along with the right kind of glazing makes it
entirely possible to restrict heat gain.

The problem with that is that it cuts down light too. I prefer to shade
with curtains, which are movable.

They are - but the heat is already _inside_ by the time the light hits
your
curtains, so you have potentially lost the battle already.

No it isn't! If our south facing room is hot because the sun is shining in
and I draw a curtain it cools perceptively and immediately :-)

I've done it lots of times. The curtain has to be lightproof of course,
which can cut down the light but it only has to shade that sunlight which is
shining directly into the room.

Thus, when Spouse and I are having breakfast in the bay window of our south
facing dining room and the sun's rays are hot we close the curtain behind
him in the morning to prevent the south eastern rays coming in and the one
behind me in the afternoon to shield those from the south west. At lunch
time, for a very short period, we have to close both. The answer would be to
have a curtain which would just cover the immediate south facing pane but we
can't be bothered :-)

I was once fascinated because on a very hot day the bees in a hive in full
sun were flying in a cloud at the front of the hive. I leaned a large slab
of stone against the side of the hive where the sun's rays were striking and
the bees all went inside and behaved normally from then on. How they knew
that the hive had cooled was another matter but my observation was that the
effect was immediate.

Mary
--
derek

Robert Gammon wrote
digitalmaster wrote
wrote
Rod Speed wrote

What matters is the cost TO THE INDIVIDUAL.

The individual considering which way to go with hot water
gets no say on what the state chooses to do with nukes.

Nor do I have any input as to whether various rebates and
incentives are the right way for the community at large to go. I
can only look at the impact that the programs have on my situation.

You sure you're paying 30c for offpeak ?

http://www.pge.com/rates/tariffs/ResTOUCurrent.xls
The baseline rate is only $0.08. That rate is very stable, but also is not very much
energy per month, varying by the season and location.

And what matters is the OP's offpeak power rate, not yours or mine.

As always. The local conditions for that person are all that
matters. Solar insolation, utility rates, Tax laws, appraisal
patterns, cost of labor, cost of materials, construction codes,
etc. It's hard enough to make comparisons across different
utilities in the same state, much less the 50 states here, or to a
different country.

Mine is completely integrated into the house design,
7 8'x8' patio doors on the north side of the house which
is 100' running East/West. I'm in the southern hemisphere.

I saw a house recently built that looks like all doors on the long side. I thought
that was for the view. I hadn't pondered the orientation. A look at Google Earth
makes me think all those doors are Southwest exposure, but that should be hot in the
summertime, without deciduous tree cover.

6' eaves all down the N side, calculated with the sun angles
to let all the sun in in winter and none in the summer.

That is sorely lacking at my house. Stubby eaves at a steep angle, so I can't even
add additional cover in a pleasing fashion.

I might have a closer look at that house with no trees. Maybe it has long shallow
eves.

In the summer the sun is more directly overhead so the extra glass
on the south side should not make the house hot.in the winter the
sun is lower on the horizon so it shines in through the glass more.

The rub to this argument is - more HOURS of daylight in the summer.
This fact coupled with higher outside temps, WILL MAKE A HOUSE WITH SOUTH FACING WINDOWS
WARMER IN THE SUMMERTIME THAN A HOUSE WITH NO SOUTH FACING WINDOWS!!!

In theory, yes, just because the windows are
poor insulation compared with a wall instead.

In practice its a minor effect when I have the doors open while the
outside temp is acceptible, for a very pleasant outside/inside effect,
and turn the swamp cooler on when the outside temp is higher than
is pleasant. A swamp cooler costs **** all to run so the theoretical
worse insulation with the glass is purely academic and I save because
I can have outside air blow right thru the house when the outside temp is
acceptible. The house isnt that thick in a N/S direction, mostly only about 20'

Mary Fisher wrote
Derek Broughton wrote

It's not hard to make the south facing windows work. You need overhangs, as pointed
out, but the angle of incidence, along with the right kind of glazing makes
it entirely possible to restrict heat gain.

The problem with that is that it cuts down light too.

No it doesnt when you calculate the eaves properly.

I prefer to shade with curtains, which are movable.

Those are inside, so the heat still gets in.

And you have to fart around adjusting them daily too.

Mary Fisher wrote:

... If our south facing room is hot because the sun is shining in
and I draw a curtain it cools perceptively and immediately :-)

That could work well with a light-colored curtain that reflects shortwave
sun back out of the window, which blocks radiation longer than 3 microns,
but an outdoor shade can work better. If a dark-colored curtain converts
shortwave sun to longwave heat (eg 10 microns at 80 F), the window won't
pass it back to the outdoors. The heat will stay trapped inside the house.
This is the original "greenhouse effect."

Nick

wrote
Derek Broughton wrote

In Northern latitudes, what may be much worse for causing
overheating is large glass expanses in West windows. West
windows get little to no heat gain in Winter, but can't be
shaded by overhangs in Summer.

I can picture the angles of incidence of the sun varying from winter
to summer. I have a covered walkway where I marked "north" by
noting the shadow of the support posts at solar noon on a winter
day. The sun never shines on that spot in the summertime.

How does one determine the desired eave overhang and angle?

I just used a properly sun angle calculator.

That was in the late 60s, bound to be plenty online now.

I would imagine that different times of day could be selected for the shade
needed. Enough shade to shield the house between 10am and 3pm?

All you really need to do is ensure that the sun doesnt enter the
doors in summer, and set the eaves overhang to ensure that.

On June 10th? Those calculations I could make,
with input from http://www.gcstudio.com/suncalc.html

I have the same question about my Solar Sponge. It will be fixed
to the azimuth of one wall, but I can set it at any elevation that I like.
Presuming that it would be most useful before noon, I was going
to use suncalc over a 9am-noon period and locate the lowest
average variation from sun angle for some fixed panel angle.
http://solarsponge.com

Its a lot simpler with windows/patio doors where you
just need to ensure that the sun doesnt enter in summer.

Derek Broughton wrote:
Robert Gammon wrote:


digitalmaster wrote:

wrote in message



In the summer the sun is more directly overhead so the extra glass on the
south side should not make the house hot.in the winter the sun is lower
on the horizon so it shines in through the glass more.


The rub to this argument is - more HOURS of daylight in the summer.
This fact coupled with higher outside temps, WILL MAKE A HOUSE WITH
SOUTH FACING WINDOWS WARMER IN THE SUMMERTIME THAN A HOUSE WITH NO SOUTH
FACING WINDOWS!!!


Please don't yell. It's completely unnecessary. It's not hard to make the
south facing windows work. You need overhangs, as pointed out, but the
angle of incidence, along with the right kind of glazing makes it entirely
possible to restrict heat gain. In Northern latitudes, what may be much
worse for causing overheating is large glass expanses in West windows.
West windows get little to no heat gain in Winter, but can't be shaded by
overhangs in Summer. I've got lots of south window, but it never gets hot
in the living room until the sun starts to set.

My garage sits facing almost due west. metal door, the garage temp
shoots thru the top in summer

wrote in message
...
Mary Fisher wrote:

... If our south facing room is hot because the sun is shining in
and I draw a curtain it cools perceptively and immediately :-)

That could work well with a light-colored curtain that reflects shortwave
sun back out of the window, which blocks radiation longer than 3 microns,
but an outdoor shade can work better. If a dark-colored curtain converts
shortwave sun to longwave heat (eg 10 microns at 80 F), the window won't
pass it back to the outdoors. The heat will stay trapped inside the house.
This is the original "greenhouse effect."

Oh for goodness' sake!

I've said that the system I use works. When we bought the curtains we didn't
ask the salesman about the physical properties of the fabric!

We don't use any kind of curtains in our greenhouse by the way, that works
well too, it doesn't get too hot because of effective and automatic
ventilation.

We protect the interior of the car from the greenhouse effect by a plastic
sheet over the windscreen when the car is parked in our (south facing)
drive. That works too, perhaps you'll be pointing out that it can't.

I know our situation, you don't.

Mary Fisher wrote:

... If our south facing room is hot because the sun is shining in
and I draw a curtain it cools perceptively and immediately :-)

That could work well with a light-colored curtain that reflects shortwave
sun back out of the window, which blocks radiation longer than 3 microns,
but an outdoor shade can work better. If a dark-colored curtain converts
shortwave sun to longwave heat (eg 10 microns at 80 F), the window won't
pass it back to the outdoors. The heat will stay trapped inside the house.
This is the original "greenhouse effect."

Oh for goodness' sake!

I've said that the system I use works. When we bought the curtains we didn't
ask the salesman about the physical properties of the fabric!

It's mainly a matter of color. Sounds like it's light-colored.

Nick

"Mary Fisher" wrote in message
t...

wrote in message
...
Mary Fisher wrote:

... If our south facing room is hot because the sun is shining in
and I draw a curtain it cools perceptively and immediately :-)

That could work well with a light-colored curtain that reflects shortwave
sun back out of the window, which blocks radiation longer than 3 microns,
but an outdoor shade can work better. If a dark-colored curtain converts
shortwave sun to longwave heat (eg 10 microns at 80 F), the window won't
pass it back to the outdoors. The heat will stay trapped inside the
house.
This is the original "greenhouse effect."

Oh for goodness' sake!

LOL!

Mary Fisher wrote:

"Derek Broughton" wrote in message
...
Mary Fisher wrote:

"Derek Broughton" wrote in message
...

It's not hard to make the
south facing windows work. You need overhangs, as pointed out, but the
angle of incidence, along with the right kind of glazing makes it
entirely possible to restrict heat gain.

The problem with that is that it cuts down light too. I prefer to shade
with curtains, which are movable.

They are - but the heat is already _inside_ by the time the light hits
your curtains, so you have potentially lost the battle already.

No it isn't! If our south facing room is hot because the sun is shining in
and I draw a curtain it cools perceptively and immediately :-)

If it's "immediate", then the only thing you're registering is the fact that
sunlight is no longer hitting _you_. Which is absolutely true. When you
block sun from actually hitting your windows, obviously the only heat that
can enter is from the thermal gradient if it's warmer outside than in.

If you allow the light to come through the window, then stop it, _something_
inside has to warm up. Light coloured curtains will certainly reflect a
significant amount of the light back outside, but some _has_ to become
heat, inside the house. If it isn't apparently heating the room as a whole,
it's your curtains. When that happens, they'll radiate the heat and
probably half of it will end up back outside - but you still end up with
more heat inside the house than you would if the light hadn't penetrated
the window in the first place. This is why i said "potentially" - if your
home is well designed (or in rainy England :-) ), that may not be too much
heat.

I've done it lots of times. The curtain has to be lightproof of course,

Preferably aluminium or reflective mylar - though that might really annoy
your neighbours!

I was once fascinated because on a very hot day the bees in a hive in full
sun were flying in a cloud at the front of the hive. I leaned a large slab
of stone against the side of the hive where the sun's rays were striking
and the bees all went inside and behaved normally from then on. How they
knew that the hive had cooled was another matter but my observation was
that the effect was immediate.

They deliberately function as a fan to pull warm air out of the hive, and I
expect they simply stop doing that as soon as the air they're moving no
longer feels too warm, but that's not the same thing as using the curtain -
because the stone kept the sun from ever touching the hive. It's the
difference between putting shutters in front of your windows and curtains
behind them.
--
derek

"Derek Broughton" wrote in message
...


If it's "immediate", then the only thing you're registering is the fact
that
sunlight is no longer hitting _you_. Which is absolutely true.

That's right. The radiant heat doesn't heat us.

I was once fascinated because on a very hot day the bees in a hive in
full
sun were flying in a cloud at the front of the hive. I leaned a large
slab
of stone against the side of the hive where the sun's rays were striking
and the bees all went inside and behaved normally from then on. How they
knew that the hive had cooled was another matter but my observation was
that the effect was immediate.

They deliberately function as a fan to pull warm air out of the hive, and
I
expect they simply stop doing that as soon as the air they're moving no
longer feels too warm, but that's not the same thing as using the
curtain -
because the stone kept the sun from ever touching the hive. It's the
difference between putting shutters in front of your windows and curtains
behind them.

You don't know bees as I do.

Mary

Mary Fisher wrote:

You don't know bees as I do.

I may, but that's hardly relevant to the physics behind trapping heat inside
your house.
--
derek

"Mary Fisher" wrote in message
t...

wrote in message
...
Mary Fisher wrote:

... If our south facing room is hot because the sun is shining in
and I draw a curtain it cools perceptively and immediately :-)

That could work well with a light-colored curtain that reflects shortwave
sun back out of the window, which blocks radiation longer than 3 microns,
but an outdoor shade can work better. If a dark-colored curtain converts
shortwave sun to longwave heat (eg 10 microns at 80 F), the window won't
pass it back to the outdoors. The heat will stay trapped inside the
house.
This is the original "greenhouse effect."

Oh for goodness' sake!

I've said that the system I use works. When we bought the curtains we
didn't ask the salesman about the physical properties of the fabric!

We don't use any kind of curtains in our greenhouse by the way, that works
well too, it doesn't get too hot because of effective and automatic
ventilation.

We protect the interior of the car from the greenhouse effect by a plastic
sheet over the windscreen when the car is parked in our (south facing)
drive. That works too, perhaps you'll be pointing out that it can't.

I know our situation, you don't.
I think what they are trying to say is that outside shade is MORE
effective.True inside shades help,but there is still some heat gain.I do
the same with white Venetian blinds...but if you put your hand close to the
blind you will notice some heat from the sunlight hitting the blind/shade.

"Derek Broughton" wrote in message
...
Mary Fisher wrote:

You don't know bees as I do.

I may, but that's hardly relevant to the physics behind trapping heat
inside
your house.

But you said, "They deliberately function as a fan to pull warm air out of
the hive, and I expect they simply stop doing that as soon as the air
they're moving no
longer feels too warm, ... "

I'd said, "on a very hot day the bees in a hive in full sun were flying in a
cloud at the front of the hive." not that they were fanning at the entrance.

Mary
--
derek

Mary Fisher wrote:


"Derek Broughton" wrote in message
...
Mary Fisher wrote:

You don't know bees as I do.

I may, but that's hardly relevant to the physics behind trapping heat
inside your house.

But you said, "They deliberately function as a fan to pull warm air out of
the hive, and I expect they simply stop doing that as soon as the air
they're moving no
longer feels too warm, ... "

I'd said, "on a very hot day the bees in a hive in full sun were flying in
a cloud at the front of the hive." not that they were fanning at the
entrance.

I wasn't there :-). It sounded like that's what you were describing.
--
derek

"Derek Broughton" wrote in message
...
Mary Fisher wrote:


"Derek Broughton" wrote in message
...
Mary Fisher wrote:

You don't know bees as I do.

I may, but that's hardly relevant to the physics behind trapping heat
inside your house.

But you said, "They deliberately function as a fan to pull warm air out
of
the hive, and I expect they simply stop doing that as soon as the air
they're moving no
longer feels too warm, ... "

I'd said, "on a very hot day the bees in a hive in full sun were flying
in
a cloud at the front of the hive." not that they were fanning at the
entrance.

I wasn't there :-). It sounded like that's what you were describing.

I described what was happening, there was no ambiguity.
--
derek

In alt.solar.thermal wrote:
You might use simple geometry to make an overhang that admits all winter
sun on 12/21 and excludes all summer sun at noon on 6/21, with some blank

My stubby little overhang shades the wall completely at noon today. That
doesn't seem sufficient. It actually looks like that might have been the
design, as the shadow is at the base of the wall at 1pm PDT. That leaves a
lot of wall exposed to the afternoon sun.

Maybe I'd rather have an overhang for the 3pm sun.

http://www.eere.energy.gov/consumer/.../mytopic=10280
says window sill on June 21 noon for my Moderate climate.

The Australian sites have more overhang, indicating 30% of window height as
an overhang, but I think that is at a latitude of 27.

Maybe a pergola, with winter-solstice angle on the boards.

--
---
Clarence A Dold - Hidden Valley Lake, CA, USA GPS: 38.8,-122.5

In alt.solar.thermal Rod Speed wrote:
I would imagine that different times of day could be selected for the
shade needed. Enough shade to shield the house between 10am and 3pm?

All you really need to do is ensure that the sun doesnt enter the doors
in summer, and set the eaves overhang to ensure that.

Shade at noon? That seems to expose a lot of afternoon sun. Shade at 2pm?
What shade times do you have?

Maybe that cuts down on the winter solar heating. It doesn't seem to.
Winter Solstice is only 27 degrees for me.

I can't plant shade trees because of the layout of the house, but I could
get away with some pergola, which would look good across the deck, and only
nominally out of place across the front door, where my wife wants some more
overhang anyway.

--
---
Clarence A Dold - Hidden Valley Lake, CA, USA GPS: 38.8,-122.5

wrote
wrote

You might use simple geometry to make an overhang that admits all
winter sun on 12/21 and excludes all summer sun at noon on 6/21,
with some blank

My stubby little overhang shades the wall completely at noon today.
That doesn't seem sufficient. It actually looks like that might have
been the design, as the shadow is at the base of the wall at 1pm PDT.
That leaves a lot of wall exposed to the afternoon sun.

Maybe I'd rather have an overhang for the 3pm sun.

http://www.eere.energy.gov/consumer/.../mytopic=10280
says window sill on June 21 noon for my Moderate climate.

The Australian sites have more overhang, indicating 30% of window
height as an overhang, but I think that is at a latitude of 27.

Nope in the mid 30s latitude.

Maybe a pergola, with winter-solstice angle on the boards.

wrote
Rod Speed wrote

I would imagine that different times of day could be selected for the
shade needed. Enough shade to shield the house between 10am and 3pm?

All you really need to do is ensure that the sun doesnt enter the
doors in summer, and set the eaves overhang to ensure that.

Shade at noon?

Nope, at any time of day.

That seems to expose a lot of afternoon sun.
Shade at 2pm? What shade times do you have?

No sun at any time of the day in summer.

Maybe that cuts down on the winter solar heating.

No it doesnt.

It doesn't seem to. Winter Solstice is only 27 degrees for me.

I can't plant shade trees because of the layout of the house,

Yeah, I deliberately ensured that the layout of the house would allow that.

but I could get away with some pergola, which would look
good across the deck, and only nominally out of place across the
front door, where my wife wants some more overhang anyway.

In alt.solar.thermal Rod Speed wrote:
wrote
Rod Speed wrote

I would imagine that different times of day could be selected for the
shade needed. Enough shade to shield the house between 10am and 3pm?

All you really need to do is ensure that the sun doesnt enter the
doors in summer, and set the eaves overhang to ensure that.

Shade at noon?

Nope, at any time of day.

That would be a long eave for me. Actually, not possible, as the sun is
visible down to the horizon in the afternoon. It's 6:30PDT, and the sun is
still shining on the house at 1.1 degrees, according to SunCalc.

That seems to expose a lot of afternoon sun.
Shade at 2pm? What shade times do you have?

No sun at any time of the day in summer.

Maybe that cuts down on the winter solar heating.

No it doesnt.

It doesn't seem to. Winter Solstice is only 27 degrees for me.

I can't plant shade trees because of the layout of the house,

Yeah, I deliberately ensured that the layout of the house would allow that.

but I could get away with some pergola, which would look
good across the deck, and only nominally out of place across the
front door, where my wife wants some more overhang anyway.



--
---
Clarence A Dold - Hidden Valley Lake, CA, USA GPS: 38.8,-122.5

In alt.solar.thermal Rod Speed wrote:
wrote
The Australian sites have more overhang, indicating 30% of window
height as an overhang, but I think that is at a latitude of 27.

Nope in the mid 30s latitude.

Australia stretchs from -12 to -38. Maybe you are in the mid-30's.

I was referring to the site
http://www.greenhouse.gov.au/yourhom...nical/fs19.htm
"For latitudes north of 27.50S the response varies with climate."

--
---
Clarence A Dold - Hidden Valley Lake, CA, USA GPS: 38.8,-122.5

wrote
Rod Speed wrote
wrote

The Australian sites have more overhang, indicating 30% of window
height as an overhang, but I think that is at a latitude of 27.

Nope in the mid 30s latitude.

Australia stretchs from -12 to -38. Maybe you are in the mid-30's.

Yes, but the bulk of the population actually lives in the mid 30s.

I was referring to the site
http://www.greenhouse.gov.au/yourhom...nical/fs19.htm
"For latitudes north of 27.50S the response varies with climate."

Thats a different issue to what was being discussed,
whether its feasible to have an eaves that ensures that
no sun enters the house in summer, but does fine in winter.

You dont really need much solar heating at 27S except in
the inland and there arent many people living there at all.

wrote
Rod Speed wrote
wrote
Rod Speed wrote

I would imagine that different times of day could
be selected for the shade needed. Enough shade
to shield the house between 10am and 3pm?

All you really need to do is ensure that the sun doesnt enter the
doors in summer, and set the eaves overhang to ensure that.

Shade at noon?

Nope, at any time of day.

That would be a long eave for me.

6' is fine here, with the glass going down to floor level.

Actually, not possible, as the sun is visible down to the horizon in the afternoon.

Its gone well past W by then here, so you still dont get any sun thru the N glass.

Most dont realise how far S the sun gets in summer, and
I didnt either until I calculated it when designing everything.

I in fact get some sun thru the S glass in summer, very late in the day, just
before sunset, but there is a dense run of trees running right along the S side
of the house with vegetation down to the ground that means there isnt any heat.

The trees were deliberately designed to produce that effect.

It's 6:30PDT, and the sun is still shining on the
house at 1.1 degrees, according to SunCalc.

See above.

That seems to expose a lot of afternoon sun.
Shade at 2pm? What shade times do you have?

No sun at any time of the day in summer.

Maybe that cuts down on the winter solar heating.

No it doesnt.

It doesn't seem to. Winter Solstice is only 27 degrees for me.

I can't plant shade trees because of the layout of the house,

Yeah, I deliberately ensured that the layout of the house would allow that.

but I could get away with some pergola, which would look
good across the deck, and only nominally out of place across the
front door, where my wife wants some more overhang anyway.

In alt.solar.thermal Rod Speed wrote:
wrote

Actually, not possible, as the sun is visible down to the horizon in
the afternoon.

Its gone well past W by then here, so you still dont get any sun thru the
N glass.

Most dont realise how far S the sun gets in summer, and
I didnt either until I calculated it when designing everything.

I've paid more attention to a lot about the sun motion since I started
looking at solar. I would incorporate some of it if I were building a
house, but there's not a lot to be done about the existing house.

I thought about azimuth as I looked out the window at the setting sun,
after making that posting. At the elevation of 1.1, it's also at azimuth
300. That's still shining some light on my house, facing at a 215 azimuth.
One of the pages suggests that extending the eaves isn't a practical
solution for houses more than 30 degrees off due south.

At 3:42 pm, the temp was 107F today. The sun was at 54 el, 255 az.
Presuming that I want to keep that light off the windows, I would need a 4
foot eave.

--
---
Clarence A Dold - Hidden Valley Lake, CA, USA GPS: 38.8,-122.5

wrote
Rod Speed wrote
wrote

Actually, not possible, as the sun is visible
down to the horizon in the afternoon.

Its gone well past W by then here, so
you still dont get any sun thru the N glass.

Most dont realise how far S the sun gets in summer, and
I didnt either until I calculated it when designing everything.

I've paid more attention to a lot about the sun motion since I started
looking at solar. I would incorporate some of it if I were building a house,

Yeah, thats what I meant in my original, by far the best time to do it.

but there's not a lot to be done about the existing house.

You can do addon solar air heaters, particularly
if you are there when the sun is shining much.

The economics and practicality of the more gung ho stuff like
attempting to store that solar gain in water etc is a lot more marginal.

I thought about azimuth as I looked out the window at the setting sun,
after making that posting. At the elevation of 1.1, it's also at
azimuth 300. That's still shining some light on my house, facing at
a 215 azimuth. One of the pages suggests that extending the eaves
isn't a practical solution for houses more than 30 degrees off due south.

Yeah, thats the main thing I did design wise, chose the block so
that the house could be long in the EW direction and due N etc.

I chose the block so that it faces into a park right down the S side
too, so the council mows it with a full tractor mower and it feels
like that is part of the house. The big line of dense trees completely
covers the ground in leaf litter, so no maintenance at all is required.

At 3:42 pm, the temp was 107F today.

We do usually get at least one burst of 10 days over 100F
most summers. It can be like walking into an oven some days.

Very dry tho, 5% is typical so swamp coolers cost peanuts to run.

I almost never have the cooler on after sundown,
open all the doors up and let the outside air in.

Only ever have the cooler on overnight maybe one night a year at most.

The sun was at 54 el, 255 az. Presuming that I want to
keep that light off the windows, I would need a 4 foot eave.

Yeah, and thats very viable light wise. My 6' eave at 9' off the
ground is fine, the main room with 3 8'x8' patio doors on the N
is very bright in winter, so bright you need to ensure that the
monitors and TVs etc have antiglare screens etc.

It was plenty light enough today which unusually had fog till
about 10am and then heavy overcast till about lunchtime.
We just had half an inch of rain yesterday, and the
room was plenty bright enough yesterday too.

"Mary Fisher" wrote in message
t...

"Derek Broughton" wrote in message
...


If it's "immediate", then the only thing you're registering is the fact
that
sunlight is no longer hitting _you_. Which is absolutely true.

That's right. The radiant heat doesn't heat us.

I was once fascinated because on a very hot day the bees in a hive in
full
sun were flying in a cloud at the front of the hive. I leaned a large
slab
of stone against the side of the hive where the sun's rays were striking
and the bees all went inside and behaved normally from then on. How they
knew that the hive had cooled was another matter but my observation was
that the effect was immediate.

They deliberately function as a fan to pull warm air out of the hive, and
I
expect they simply stop doing that as soon as the air they're moving no
longer feels too warm, but that's not the same thing as using the
curtain -
because the stone kept the sun from ever touching the hive. It's the
difference between putting shutters in front of your windows and curtains
behind them.

You don't know bees as I do.

What do you mean? Some of my best friends are bees.