Outdoor thermometer placement
 

I can't seem to get this right. : Can't put it on the
roof with the other sensors as the deliberate exposure that
the roof affords those others interferes with the accuracy
of the temperature reported.

And, mounting it on the back porch ("up" out of the way)
shades it from direct sunlight but "keeps it warm" in the
colder weather due to heat trapped by the roof of the porch
(the same roof that *shades* it from the Sun).

So, it seems like the trick is to find shade without an
"overhead covering"? (contradiction in terms??)

I'll try the porch -- but much closer to the ground (farther
from the heat-trapping ceiling)?

Outdoor thermometer placement
 

On Sunday, December 27, 2015 at 9:24:09 AM UTC-5, Don Y wrote:
I can't seem to get this right. : Can't put it on the
roof with the other sensors as the deliberate exposure that
the roof affords those others interferes with the accuracy
of the temperature reported.

And, mounting it on the back porch ("up" out of the way)
shades it from direct sunlight but "keeps it warm" in the
colder weather due to heat trapped by the roof of the porch
(the same roof that *shades* it from the Sun).

So, it seems like the trick is to find shade without an
"overhead covering"? (contradiction in terms??)

I'll try the porch -- but much closer to the ground (farther
from the heat-trapping ceiling)?

North side of the house? Works for me.

Outdoor thermometer placement
 

I have two. One outside an east-side window
and one outside a west-side window. Except for
brief period around lunchtime there's always one
in the shade. I should acknowledge, though, that
I'm not a stickler. This morning it was low 40s.
41? 43? I don't really care. I just want an idea of
what to expect when I go out.

Outdoor thermometer placement
 

On 12/27/2015 7:39 AM, Mayayana wrote:
I have two. One outside an east-side window
and one outside a west-side window. Except for
brief period around lunchtime there's always one
in the shade. I should acknowledge, though, that
I'm not a stickler. This morning it was low 40s.
41? 43? I don't really care. I just want an idea of
what to expect when I go out.

I'm not interested in personal comfort as much
as having "real data" for the HVAC system and
to know whether the citrus trees are in jeopardy.

E.g., Mandarins get upset at 32 (not 30 or 34)
but Navels will tolerate 28 (but not 26). The
mechanisms used to protect them usually only afford
a couple (3 or 4?) degrees of added protection -- but,
only when you *know* they need to be used.

I also can't understand why it always gets *colder*
as the Sun is rising!

Outdoor thermometer placement
 

On Sun, 27 Dec 2015 07:49:30 -0700
Don Y wrote:

I also can't understand why it always gets *colder*
as the Sun is rising!

Then stop playing weather person.

Outdoor thermometer placement
 

On 12/27/2015 9:24 AM, Don Y wrote:
I can't seem to get this right. : Can't put it on the
roof with the other sensors as the deliberate exposure that
the roof affords those others interferes with the accuracy
of the temperature reported.

And, mounting it on the back porch ("up" out of the way)
shades it from direct sunlight but "keeps it warm" in the
colder weather due to heat trapped by the roof of the porch
(the same roof that *shades* it from the Sun).

So, it seems like the trick is to find shade without an
"overhead covering"? (contradiction in terms??)

I'll try the porch -- but much closer to the ground (farther
from the heat-trapping ceiling)?

How about under the porch? In my case the deck off the kitchen is 8'
above the ground and the sensor is mounted below it, in the shade.
Proper position is 4" to 6" above ground and with good airflow.

To follow NWS standards it should be placed at a distance 4X the height
of the nearest structure, but that is impossible for most of us.

Outdoor thermometer placement
 

On 12/27/2015 9:49 AM, Don Y wrote:

I also can't understand why it always gets *colder*
as the Sun is rising!


All objects gain heat from outside sources and radiate it away at the
same time. When more radiant heat is lost than gained, the object cools.
When more heat is gained than lost, it warms. If they are balanced, the
temperature remains constant. Okay… that’s pretty basic. Between sunset
and sunrise, the Earth’s surface gathers no solar energy but continues
to radiate away its stored heat. During the night, the surface also
loses radiant heat faster than it steals heat from other sources, and
thus its temperature, and that of the air in contact with it, drops
steadily. At dawn, when the first light beams across the landscape, the
incoming solar radiation is very weak. It does not yet have enough
strength to counter all the heat escaping from the surface. As a result,
the surface continues to lose heat for some time following sunrise, and
the air temperature continues to fall. At some point, the solar rays
shine strongly enough to counter the heat loss. The gain-loss balance is
shifted, and the air finally begins to warm up. As a rule of thumb: the
coldest temperature is about an hour after sunrise.

Reference
https://www.physicsforums.com/thread...unrise.756343/

Outdoor thermometer placement
 

On 12/27/2015 8:11 AM, Ed Pawlowski wrote:
On 12/27/2015 9:49 AM, Don Y wrote:

I also can't understand why it always gets *colder*
as the Sun is rising!


All objects gain heat from outside sources and radiate it away at the same
time. When more radiant heat is lost than gained, the object cools. When more
heat is gained than lost, it warms. If they are balanced, the temperature
remains constant. Okay… that’s pretty basic. Between sunset and sunrise, the
Earth’s surface gathers no solar energy but continues to radiate away its
stored heat. During the night, the surface also loses radiant heat faster than
it steals heat from other sources, and thus its temperature, and that of the
air in contact with it, drops steadily. At dawn, when the first light beams
across the landscape, the incoming solar radiation is very weak. It does not
yet have enough strength to counter all the heat escaping from the surface. As
a result, the surface continues to lose heat for some time following sunrise,
and the air temperature continues to fall. At some point, the solar rays shine
strongly enough to counter the heat loss. The gain-loss balance is shifted, and
the air finally begins to warm up. As a rule of thumb: the coldest temperature
is about an hour after sunrise.

Reference
https://www.physicsforums.com/thread...unrise.756343/

But that doesn't explain why it gets *colder*.

I.e., temperature falls through the evening and STABILIZES in the wee
hours of the morning. And *stays* that way -- for HOURS! Until just as
the sun rises. *Then*, it starts downward!

Outdoor thermometer placement
 

On 12/27/2015 8:03 AM, Ed Pawlowski wrote:
On 12/27/2015 9:24 AM, Don Y wrote:
I can't seem to get this right. : Can't put it on the
roof with the other sensors as the deliberate exposure that
the roof affords those others interferes with the accuracy
of the temperature reported.

And, mounting it on the back porch ("up" out of the way)
shades it from direct sunlight but "keeps it warm" in the
colder weather due to heat trapped by the roof of the porch
(the same roof that *shades* it from the Sun).

So, it seems like the trick is to find shade without an
"overhead covering"? (contradiction in terms??)

I'll try the porch -- but much closer to the ground (farther
from the heat-trapping ceiling)?

How about under the porch? In my case the deck off the kitchen is 8' above the
ground and the sensor is mounted below it, in the shade. Proper position is 4"
to 6" above ground and with good airflow.

We're "at grade" so no "below" possible.

Current installation is on the back porch, a couple of feet below the
"roof"/ceiling -- high enough to be out of the way yet not so high
that I can't easily reach it with my outstretched arm.

This consistently reads warmer than "actual" -- because the roof and
house trap too much air (despite the porch/patio protruding out from the
house -- unobstructed on 3 sides).

I know this by comparing to another "thermometer" located out in the
middle of the yard (*that* one is useless during daylight hours as
it reads MUCH hotter than normal when the sun cooks it!).

To follow NWS standards it should be placed at a distance 4X the height of the
nearest structure, but that is impossible for most of us.

Outdoor thermometer placement
 

On 12/27/2015 9:18 AM, Don Y wrote:
On 12/27/2015 8:11 AM, Ed Pawlowski wrote:
On 12/27/2015 9:49 AM, Don Y wrote:

I also can't understand why it always gets *colder*
as the Sun is rising!


All objects gain heat from outside sources and radiate it away at the
same
time. When more radiant heat is lost than gained, the object cools.
When more
heat is gained than lost, it warms. If they are balanced, the temperature
remains constant. Okay… that’s pretty basic. Between sunset and
sunrise, the
Earth’s surface gathers no solar energy but continues to radiate away its
stored heat. During the night, the surface also loses radiant heat
faster than
it steals heat from other sources, and thus its temperature, and that
of the
air in contact with it, drops steadily. At dawn, when the first light
beams
across the landscape, the incoming solar radiation is very weak. It
does not
yet have enough strength to counter all the heat escaping from the
surface. As
a result, the surface continues to lose heat for some time following
sunrise,
and the air temperature continues to fall. At some point, the solar
rays shine
strongly enough to counter the heat loss. The gain-loss balance is
shifted, and
the air finally begins to warm up. As a rule of thumb: the coldest
temperature
is about an hour after sunrise.

Reference
https://www.physicsforums.com/thread...unrise.756343/


But that doesn't explain why it gets *colder*.

I.e., temperature falls through the evening and STABILIZES in the wee
hours of the morning. And *stays* that way -- for HOURS! Until just as
the sun rises. *Then*, it starts downward!

Air mass also is _not_ stagnant; all of the other local and regional
effects are going on at the same time. If there's a consistent pattern
of such (and I seriously doubt it is _every_ day), there's some other
effects locally going on causing morning air currents or whatever....It
might even in a local location be owing to other non-meterological
causes such as perhaps there's a large industrial operation which starts
operation and a heat exchanger or somesuch at that time...

No way to say specifically w/o much more information.

--

Outdoor thermometer placement
 

On 12/27/2015 8:26 AM, dpb wrote:
On 12/27/2015 9:18 AM, Don Y wrote:
On 12/27/2015 8:11 AM, Ed Pawlowski wrote:
On 12/27/2015 9:49 AM, Don Y wrote:

I also can't understand why it always gets *colder*
as the Sun is rising!


All objects gain heat from outside sources and radiate it away at the
same
time. When more radiant heat is lost than gained, the object cools.
When more
heat is gained than lost, it warms. If they are balanced, the temperature
remains constant. Okay… that’s pretty basic. Between sunset and
sunrise, the
Earth’s surface gathers no solar energy but continues to radiate away its
stored heat. During the night, the surface also loses radiant heat
faster than
it steals heat from other sources, and thus its temperature, and that
of the
air in contact with it, drops steadily. At dawn, when the first light
beams
across the landscape, the incoming solar radiation is very weak. It
does not
yet have enough strength to counter all the heat escaping from the
surface. As
a result, the surface continues to lose heat for some time following
sunrise,
and the air temperature continues to fall. At some point, the solar
rays shine
strongly enough to counter the heat loss. The gain-loss balance is
shifted, and
the air finally begins to warm up. As a rule of thumb: the coldest
temperature
is about an hour after sunrise.

Reference
https://www.physicsforums.com/thread...unrise.756343/



But that doesn't explain why it gets *colder*.

I.e., temperature falls through the evening and STABILIZES in the wee
hours of the morning. And *stays* that way -- for HOURS! Until just as
the sun rises. *Then*, it starts downward!

Air mass also is _not_ stagnant; all of the other local and regional effects
are going on at the same time. If there's a consistent pattern of such (and I
seriously doubt it is _every_ day), there's some other effects locally going on
causing morning air currents or whatever....It might even in a local location
be owing to other non-meterological causes such as perhaps there's a large
industrial operation which starts operation and a heat exchanger or somesuch at
that time...

No way to say specifically w/o much more information.

Oh, I'm *convinced* it is a local phenomenon! We are located at the
confluence of two large washes, near the foothills of a (small) mountain
range. Our (winter) microclimate is driven by cold air cascading
down the mountain slopes and settling into the washes. Eventually,
there's "enough" that it overfills the washes and starts to
affect the properties adjoining (we're a bit uphill from the washes
but it's all a matter of degrees).

*But*, I can't see why *more* "cold air" would fall out of the
mountains as the rising Sun strikes them! Nor can I see anyplace
where "stored" cold air could be drawn in.

(We are in an entirely residential area with only "storefronts"
a mile or so away, "uphill" -- and farther from the washes -- from us.

Outdoor thermometer placement
 

On 12/27/2015 8:24 AM, Don Y wrote:
I can't seem to get this right. : Can't put it on the
roof with the other sensors as the deliberate exposure that
the roof affords those others interferes with the accuracy
of the temperature reported.

And, mounting it on the back porch ("up" out of the way)
shades it from direct sunlight but "keeps it warm" in the
colder weather due to heat trapped by the roof of the porch
(the same roof that *shades* it from the Sun).

So, it seems like the trick is to find shade without an
"overhead covering"? (contradiction in terms??)

I'll try the porch -- but much closer to the ground (farther
from the heat-trapping ceiling)?

You've got a special situation; if you're serious about grove protection
I'd suggest getting in touch w/ the UofFL citrus folk--

www.crec.ifas.ufl.edu/

--

Outdoor thermometer placement
 

"dpb" wrote in message
...
On 12/27/2015 9:18 AM, Don Y wrote:
On 12/27/2015 8:11 AM, Ed Pawlowski wrote:
On 12/27/2015 9:49 AM, Don Y wrote:

I also can't understand why it always gets *colder*
as the Sun is rising!


All objects gain heat from outside sources and radiate
it away at the
same
time. When more radiant heat is lost than gained, the
object cools.
When more
heat is gained than lost, it warms. If they are
balanced, the temperature
remains constant. Okay… that’s pretty basic. Between
sunset and
sunrise, the
Earth’s surface gathers no solar energy but continues to
radiate away its
stored heat. During the night, the surface also loses
radiant heat
faster than
it steals heat from other sources, and thus its
temperature, and that
of the
air in contact with it, drops steadily. At dawn, when
the first light
beams
across the landscape, the incoming solar radiation is
very weak. It
does not
yet have enough strength to counter all the heat
escaping from the
surface. As
a result, the surface continues to lose heat for some
time following
sunrise,
and the air temperature continues to fall. At some
point, the solar
rays shine
strongly enough to counter the heat loss. The gain-loss
balance is
shifted, and
the air finally begins to warm up. As a rule of thumb:
the coldest
temperature
is about an hour after sunrise.

Reference
https://www.physicsforums.com/thread...unrise.756343/


But that doesn't explain why it gets *colder*.

I.e., temperature falls through the evening and
STABILIZES in the wee
hours of the morning. And *stays* that way -- for HOURS!
Until just as
the sun rises. *Then*, it starts downward!

Air mass also is _not_ stagnant; all of the other local
and regional effects are going on at the same time. If
there's a consistent pattern of such (and I seriously
doubt it is _every_ day), there's some other effects
locally going on causing morning air currents or
whatever....It might even in a local location be owing to
other non-meterological causes such as perhaps there's a
large industrial operation which starts operation and a
heat exchanger or somesuch at that time...

No way to say specifically w/o much more information.


Try this: the earth cools at night causing the humidity to
drop and the moisture condenses as dew. When the
sun comes up it begins to evaporate the dew and when
water changes back to vapor it absorbs a lot of heat!

Outdoor thermometer placement
 

On 12/27/2015 8:24 AM, Don Y wrote:
I can't seem to get this right. : Can't put it on the
roof with the other sensors as the deliberate exposure that
the roof affords those others interferes with the accuracy
of the temperature reported.

And, mounting it on the back porch ("up" out of the way)
shades it from direct sunlight but "keeps it warm" in the
colder weather due to heat trapped by the roof of the porch
(the same roof that *shades* it from the Sun).

So, it seems like the trick is to find shade without an
"overhead covering"? (contradiction in terms??)

I'll try the porch -- but much closer to the ground (farther
from the heat-trapping ceiling)?

We have 2 of them. One on the front porch and one outside the back of
the house by a window. The temps are pretty close even though the shade
hits both of them during the day at some point. We also have a
thermometer on our vehicles in the driveway, too. It's usually only a
couple of degrees difference in temp from the porch to the driveway.

--
Maggie

Outdoor thermometer placement
 

On 12/27/2015 8:39 AM, Mayayana wrote:
I have two. One outside an east-side window
and one outside a west-side window. Except for
brief period around lunchtime there's always one
in the shade. I should acknowledge, though, that
I'm not a stickler. This morning it was low 40s.
41? 43? I don't really care. I just want an idea of
what to expect when I go out.



I'll often just touch the window to see how cold it feels to gauge how
many layers of sweater and coat I need before going outside.

--
Maggie

Outdoor thermometer placement
 

On 12/27/2015 8:49 AM, Don Y wrote:
On 12/27/2015 7:39 AM, Mayayana wrote:
I have two. One outside an east-side window
and one outside a west-side window. Except for
brief period around lunchtime there's always one
in the shade. I should acknowledge, though, that
I'm not a stickler. This morning it was low 40s.
41? 43? I don't really care. I just want an idea of
what to expect when I go out.

I'm not interested in personal comfort as much
as having "real data" for the HVAC system and
to know whether the citrus trees are in jeopardy.

E.g., Mandarins get upset at 32 (not 30 or 34)
but Navels will tolerate 28 (but not 26). The
mechanisms used to protect them usually only afford
a couple (3 or 4?) degrees of added protection -- but,
only when you *know* they need to be used.

I also can't understand why it always gets *colder*
as the Sun is rising!


You could put them on your trees that you want to keep track of temps
around them.

--
Maggie

Outdoor thermometer placement
 

On 12/27/2015 9:38 AM, Don Y wrote:
On 12/27/2015 8:26 AM, dpb wrote:
On 12/27/2015 9:18 AM, Don Y wrote:
On 12/27/2015 8:11 AM, Ed Pawlowski wrote:
On 12/27/2015 9:49 AM, Don Y wrote:

I also can't understand why it always gets *colder*
as the Sun is rising!


All objects gain heat from outside sources and radiate it away at the
same
time. When more radiant heat is lost than gained, the object cools.
When more
heat is gained than lost, it warms. If they are balanced, the
temperature
remains constant. Okay… that’s pretty basic. Between sunset and
sunrise, the
Earth’s surface gathers no solar energy but continues to radiate
away its
stored heat. During the night, the surface also loses radiant heat
faster than
it steals heat from other sources, and thus its temperature, and that
of the
air in contact with it, drops steadily. At dawn, when the first light
beams
across the landscape, the incoming solar radiation is very weak. It
does not
yet have enough strength to counter all the heat escaping from the
surface. As
a result, the surface continues to lose heat for some time following
sunrise,
and the air temperature continues to fall. At some point, the solar
rays shine
strongly enough to counter the heat loss. The gain-loss balance is
shifted, and
the air finally begins to warm up. As a rule of thumb: the coldest
temperature
is about an hour after sunrise.

Reference
https://www.physicsforums.com/thread...unrise.756343/




But that doesn't explain why it gets *colder*.

I.e., temperature falls through the evening and STABILIZES in the wee
hours of the morning. And *stays* that way -- for HOURS! Until just as
the sun rises. *Then*, it starts downward!

Air mass also is _not_ stagnant; all of the other local and regional
effects
are going on at the same time. If there's a consistent pattern of
such (and I
seriously doubt it is _every_ day), there's some other effects locally
going on
causing morning air currents or whatever....It might even in a local
location
be owing to other non-meterological causes such as perhaps there's a
large
industrial operation which starts operation and a heat exchanger or
somesuch at
that time...

No way to say specifically w/o much more information.

Oh, I'm *convinced* it is a local phenomenon! We are located at the
confluence of two large washes, near the foothills of a (small) mountain
range. Our (winter) microclimate is driven by cold air cascading
down the mountain slopes and settling into the washes. Eventually,
there's "enough" that it overfills the washes and starts to
affect the properties adjoining (we're a bit uphill from the washes
but it's all a matter of degrees).

*But*, I can't see why *more* "cold air" would fall out of the
mountains as the rising Sun strikes them! Nor can I see anyplace
where "stored" cold air could be drawn in.

(We are in an entirely residential area with only "storefronts"
a mile or so away, "uphill" -- and farther from the washes -- from us.


Hot air rises and cold air falls?

--
Maggie

Outdoor thermometer placement
 

On Sun, 27 Dec 2015 10:39:23 -0600, Muggles wrote:

On 12/27/2015 9:38 AM, Don Y wrote:

I also can't understand why it always gets *colder*
as the Sun is rising!

Hot air rises and cold air falls?


That was my thought. There is a little river valley
just south of my house. I can feel the temperature change
if I ride my motorcycle into that little valley just a bit
after sundown. It's distinctly cooler in that little valley.
The sun would heat the upper air first as it comes up in
the morning forcing the cooler air down.


--
Using Opera's mail client: http://www.opera.com/mail/

Outdoor thermometer placement
 

On Sun, 27 Dec 2015 07:49:30 -0700, Don Y
wrote:

On 12/27/2015 7:39 AM, Mayayana wrote:
I have two. One outside an east-side window
and one outside a west-side window. Except for
brief period around lunchtime there's always one
in the shade. I should acknowledge, though, that
I'm not a stickler. This morning it was low 40s.
41? 43? I don't really care. I just want an idea of
what to expect when I go out.

I'm not interested in personal comfort as much
as having "real data" for the HVAC system and
to know whether the citrus trees are in jeopardy.

E.g., Mandarins get upset at 32 (not 30 or 34)
but Navels will tolerate 28 (but not 26). The
mechanisms used to protect them usually only afford
a couple (3 or 4?) degrees of added protection -- but,
only when you *know* they need to be used.


In that case you need the sensors at the trees.

Outdoor thermometer placement
 

"Don Y" wrote in message ...
On 12/27/2015 7:39 AM, Mayayana wrote:
I have two. One outside an east-side window
and one outside a west-side window. Except for
brief period around lunchtime there's always one
in the shade. I should acknowledge, though, that
I'm not a stickler. This morning it was low 40s.
41? 43? I don't really care. I just want an idea of
what to expect when I go out.

I'm not interested in personal comfort as much
as having "real data" for the HVAC system and
to know whether the citrus trees are in jeopardy.

Put one sensor on the inlet to the HVAC, and another one under a citrus tree. If you're worried about the sun affecting it, add something like an umbrella.

E.g., Mandarins get upset at 32 (not 30 or 34)
but Navels will tolerate 28 (but not 26). The
mechanisms used to protect them usually only afford
a couple (3 or 4?) degrees of added protection -- but,
only when you *know* they need to be used.

I also can't understand why it always gets *colder*
as the Sun is rising!

Outdoor thermometer placement
 

On 12/27/2015 11:16 AM, Dean Hoffman wrote:
On Sun, 27 Dec 2015 10:39:23 -0600, Muggles wrote:

On 12/27/2015 9:38 AM, Don Y wrote:

I also can't understand why it always gets *colder*
as the Sun is rising!

Hot air rises and cold air falls?


That was my thought. There is a little river valley
just south of my house. I can feel the temperature change
if I ride my motorcycle into that little valley just a bit
after sundown. It's distinctly cooler in that little valley.
The sun would heat the upper air first as it comes up in
the morning forcing the cooler air down.



Yeah. That's makes sense.

--
Maggie

Outdoor thermometer placement
 

"Don Y"
Reference
https://www.physicsforums.com/thread...unrise.756343/

But that doesn't explain why it gets *colder*.

I.e., temperature falls through the evening and STABILIZES
in the wee
hours of the morning. And *stays* that way -- for HOURS!
Until just as
the sun rises. *Then*, it starts downward!

As the morning dew evaporates it absorbs a lot of heat,
that's
why it is cooler. Simple as that ... no brainer...
phil k

Outdoor thermometer placement
 

Muggles wrote:
On 12/27/2015 8:49 AM, Don Y wrote:
On 12/27/2015 7:39 AM, Mayayana wrote:
I have two. One outside an east-side window
and one outside a west-side window. Except for
brief period around lunchtime there's always one
in the shade. I should acknowledge, though, that
I'm not a stickler. This morning it was low 40s.
41? 43? I don't really care. I just want an idea of
what to expect when I go out.

I'm not interested in personal comfort as much
as having "real data" for the HVAC system and
to know whether the citrus trees are in jeopardy.

E.g., Mandarins get upset at 32 (not 30 or 34)
but Navels will tolerate 28 (but not 26). The
mechanisms used to protect them usually only afford
a couple (3 or 4?) degrees of added protection -- but,
only when you *know* they need to be used.

I also can't understand why it always gets *colder*
as the Sun is rising!


You could put them on your trees that you want to keep track of temps
around them.

MY Davis weather station is on a ~10 feet pole in the front yard, one
thermometer inside the screened patio hanging from the ceiling. Indoor
has thermostat one.

Outdoor thermometer placement
 

On Sun, 27 Dec 2015 07:24:12 -0700, Don Y
wrote:

I can't seem to get this right. : Can't put it on the
roof with the other sensors as the deliberate exposure that
the roof affords those others interferes with the accuracy
of the temperature reported.

And, mounting it on the back porch ("up" out of the way)
shades it from direct sunlight but "keeps it warm" in the
colder weather due to heat trapped by the roof of the porch
(the same roof that *shades* it from the Sun).

So, it seems like the trick is to find shade without an
"overhead covering"? (contradiction in terms??)

I'll try the porch -- but much closer to the ground (farther
from the heat-trapping ceiling)?
Put it inside a 3 foot long 6 inch white plastic pipe, at least 3
feet off the ground and open at both ends. Mount the thermometer in
the center of the pipe. Of course this only works for remote reading
thermometers.

Outdoor thermometer placement
 

On Sun, 27 Dec 2015 07:49:30 -0700, Don Y
wrote:

On 12/27/2015 7:39 AM, Mayayana wrote:
I have two. One outside an east-side window
and one outside a west-side window. Except for
brief period around lunchtime there's always one
in the shade. I should acknowledge, though, that
I'm not a stickler. This morning it was low 40s.
41? 43? I don't really care. I just want an idea of
what to expect when I go out.

I'm not interested in personal comfort as much
as having "real data" for the HVAC system and
to know whether the citrus trees are in jeopardy.

E.g., Mandarins get upset at 32 (not 30 or 34)
but Navels will tolerate 28 (but not 26). The
mechanisms used to protect them usually only afford
a couple (3 or 4?) degrees of added protection -- but,
only when you *know* they need to be used.

I also can't understand why it always gets *colder*
as the Sun is rising!
"it is always darker just before dawn"
Any residual heat has run out and the heat of the sun has not yet
arrived - Generally the coldest time of the night is after 3am and
before 7am.

Outdoor thermometer placement
 

On 12/27/2015 12:57 PM, Phil Kangas wrote:

"Don Y"
Reference
https://www.physicsforums.com/thread...unrise.756343/


But that doesn't explain why it gets *colder*.

I.e., temperature falls through the evening and STABILIZES in the wee
hours of the morning. And *stays* that way -- for HOURS! Until just as
the sun rises. *Then*, it starts downward!

As the morning dew evaporates it absorbs a lot of heat, that's
why it is cooler. Simple as that ... no brainer...
phil k

That's possible if there is dew (frost) on the mountain; there's
nothing *here* at its base! That would also be more consistent
with the timing: we are often not yet in sunlight -- but the
south-facing slope of the mountains immediately to our north is!

It would also explain why the phenomenon is local to our immediate
area and not (as much) for folks several blocks further south (higher
elevation)

Outdoor thermometer placement
 

On 12/27/2015 10:49 AM, Vic Smith wrote:
On Sun, 27 Dec 2015 07:49:30 -0700, Don Y

I'm not interested in personal comfort as much
as having "real data" for the HVAC system and
to know whether the citrus trees are in jeopardy.

E.g., Mandarins get upset at 32 (not 30 or 34)
but Navels will tolerate 28 (but not 26). The
mechanisms used to protect them usually only afford
a couple (3 or 4?) degrees of added protection -- but,
only when you *know* they need to be used.

In that case you need the sensors at the trees.

Trees are within 10-20 feet of the house. So, there's
likely no difference in temperatures there vs here
IN THE ABSENCE OF MAN-MADE INFLUENCES.

Locating them at/in the trees would expose them to the
daytime sun.

For example, I was outside a few minutes ago checking the
fruit. I moved a thermometer (not a wired sensor) from
it's location on the porch out into the yard -- 12 feet
away. In the time it took for me to walk to three of
the trees and back, the registered temperature had
climbed from 51F to 72F. (I'm *sure* the air temperature
hadn't changed that much! : )

Nearby weather reporting sites range from ~47F to ~57F.
The closest to my location (unsure of its relative elevation)
reports 50F -- which is in line with my 51.

[My 51 is usually high due to its location in a "heat trap"]

Outdoor thermometer placement
 

On 12/27/2015 8:45 AM, dpb wrote:
On 12/27/2015 8:24 AM, Don Y wrote:
I can't seem to get this right. : Can't put it on the
roof with the other sensors as the deliberate exposure that
the roof affords those others interferes with the accuracy
of the temperature reported.

And, mounting it on the back porch ("up" out of the way)
shades it from direct sunlight but "keeps it warm" in the
colder weather due to heat trapped by the roof of the porch
(the same roof that *shades* it from the Sun).

So, it seems like the trick is to find shade without an
"overhead covering"? (contradiction in terms??)

I'll try the porch -- but much closer to the ground (farther
from the heat-trapping ceiling)?

You've got a special situation; if you're serious about grove protection I'd
suggest getting in touch w/ the UofFL citrus folk--

grin Not a "grove", just half a dozen trees.

There's only so much we can realistically do; can't deploy smudge pots
as there are too many structures nearby; can't deploy fans as the trees
aren't arranged in a "grove" (we'd need several small fans, instead).

We opt to cover the trees and use small heat sources to help encourage
convective air flow (has to work in case it's also raining).

I've covetously eyed the "blow up figures" that folks put out for
holiday decorations thinking that I might be able to repurpose the
fans used in them. They *should* be able to tolerate rain, right?

OTOH, they are covered by a large inflatable fabric sack so I'm
not sure how well they actually fare in a downpour! (do people
actually have them inflated when its raining??)

The more practical solution is to move to higher ground farther
from the wash.

Or, stop growing fruit that doesn't like the weather!! :

[I've repeatedly threatened SWMBO that when the next REALLY cold
spell comes through and whacks the trees, I'll use them in the
smoker!! : ]

Outdoor thermometer placement
 

On Sun, 27 Dec 2015 07:24:12 -0700, Don Y
wrote:

I can't seem to get this right. : Can't put it on the
roof with the other sensors as the deliberate exposure that
the roof affords those others interferes with the accuracy
of the temperature reported.

And, mounting it on the back porch ("up" out of the way)
shades it from direct sunlight but "keeps it warm" in the
colder weather due to heat trapped by the roof of the porch
(the same roof that *shades* it from the Sun).

So, it seems like the trick is to find shade without an
"overhead covering"? (contradiction in terms??)

I'll try the porch -- but much closer to the ground (farther
from the heat-trapping ceiling)?

I have a tree about 6ft. from a house window. I put a thermometer on the
tree. During rain, water ran down the tree trunk and would get inside
the thermometer. I finally drilled a hole in the bottom of the plastic
front of it to let the water drain out, but eventually it ruined the
thermometer. Now I have a new one, but I mounted it on a board, put a
piece of tin at the top of the board to hang over the thermometer and
divert the water away from it. Then I screwed the whole board to the
tree. I hope this works better.

Outdoor thermometer placement
 

On Sun, 27 Dec 2015 08:16:30 -0700, Don Y
wrote:

Temperatures on the south end of our street (three blocks from here)
are 2 or 3 degrees warmer (Spring comes to them 2 weeks sooner
than for us -- as measured by when *their* flowers first bloom
vs. ours)

In a small nearby town, there are 4 signs with the temperature. (2
banks, one gas station, and a community sign). NONE of them are ever the
same. They vary by as much as 6 deg. All of them are within one half
mile. I compared them to my cellphone weather, and the gas station is
always the most accurate (and it's also the newest sign). No thermometer
is 100% accurate.....

Outdoor thermometer placement
 

On Sun, 27 Dec 2015 07:49:30 -0700, Don Y
wrote:

On 12/27/2015 7:39 AM, Mayayana wrote:
I have two. One outside an east-side window
and one outside a west-side window. Except for
brief period around lunchtime there's always one
in the shade. I should acknowledge, though, that
I'm not a stickler. This morning it was low 40s.
41? 43? I don't really care. I just want an idea of
what to expect when I go out.

Right. If I want to know the exact temperature, I go outside.

I'm not interested in personal comfort as much
as having "real data" for the HVAC system and
to know whether the citrus trees are in jeopardy.

E.g., Mandarins get upset at 32 (not 30 or 34)
but Navels will tolerate 28 (but not 26). The
mechanisms used to protect them usually only afford
a couple (3 or 4?) degrees of added protection -- but,
only when you *know* they need to be used.

I also can't understand why it always gets *colder*
as the Sun is rising!

It's also darkest just before the dawn! So I hear.

http://www.phrases.org.uk/meanings/darkest-hour.html

Outdoor thermometer placement
 

| I'll often just touch the window to see how cold it feels to gauge how
| many layers of sweater and coat I need before going outside.
|

Hopefully you don't end up getting double
insulated glass. You could freeze to death. :)

Outdoor thermometer placement
 

On Sun, 27 Dec 2015 10:31:12 -0600, Muggles wrote:

On 12/27/2015 8:39 AM, Mayayana wrote:
I have two. One outside an east-side window
and one outside a west-side window. Except for
brief period around lunchtime there's always one
in the shade. I should acknowledge, though, that
I'm not a stickler. This morning it was low 40s.
41? 43? I don't really care. I just want an idea of
what to expect when I go out.



I'll often just touch the window to see how cold it feels to gauge how
many layers of sweater and coat I need before going outside.

Luddite!

Outdoor thermometer placement
 

On Sun, 27 Dec 2015 20:32:02 -0500, "Mayayana"
wrote:

| I'll often just touch the window to see how cold it feels to gauge how
| many layers of sweater and coat I need before going outside.
|

Hopefully you don't end up getting double
insulated glass. You could freeze to death. :)

Or worse yet - tripple glazed windows

Outdoor thermometer placement
 

On 12/27/2015 4:40 PM, Don Y wrote:
On 12/27/2015 8:45 AM, dpb wrote:
On 12/27/2015 8:24 AM, Don Y wrote:
I can't seem to get this right. : Can't put it on the
roof with the other sensors as the deliberate exposure that
the roof affords those others interferes with the accuracy
of the temperature reported.

And, mounting it on the back porch ("up" out of the way)
shades it from direct sunlight but "keeps it warm" in the
colder weather due to heat trapped by the roof of the porch
(the same roof that *shades* it from the Sun).

So, it seems like the trick is to find shade without an
"overhead covering"? (contradiction in terms??)

I'll try the porch -- but much closer to the ground (farther
from the heat-trapping ceiling)?

You've got a special situation; if you're serious about grove
protection I'd
suggest getting in touch w/ the UofFL citrus folk--

grin Not a "grove", just half a dozen trees.

There's only so much we can realistically do; can't deploy smudge pots
as there are too many structures nearby; can't deploy fans as the trees
aren't arranged in a "grove" (we'd need several small fans, instead).

We opt to cover the trees and use small heat sources to help encourage
convective air flow (has to work in case it's also raining).

I've covetously eyed the "blow up figures" that folks put out for
holiday decorations thinking that I might be able to repurpose the
fans used in them. They *should* be able to tolerate rain, right?

OTOH, they are covered by a large inflatable fabric sack so I'm
not sure how well they actually fare in a downpour! (do people
actually have them inflated when its raining??)

The more practical solution is to move to higher ground farther
from the wash.

Or, stop growing fruit that doesn't like the weather!! :

[I've repeatedly threatened SWMBO that when the next REALLY cold
spell comes through and whacks the trees, I'll use them in the
smoker!! : ]

I've not been to grandparents' old place in TX Valley in years to know
what they now use (of course, it's two-three generations removed from
grandparents now) but for temp measurement I'd think you'd get by pretty
nicely with just a covered box near where you really need the detail
info; as you point out if you're really after that local
micro-difference to protect individual tree(s) it may not be enough
unless you go for it in an all or nothing fashion whenever you do get an
indication (likely the most reasonable alternative). But, as another I
think noted, I've got a Davis Instruments weather station that seems to
be quite accurate simply with the sun shielding they come with "out of
the box" -- it sits out in the midday sun in SW KS at 100+ F w/o
measuring ridiculously high temps that occur from directly-exposed
thermometers.

The standard thermometer on the north side of the house at the top of
the porch also has always seemed pretty good -- it's 8' or so, roughly
from actual outside wall of the house so the heating effects don't seem
very influential as far as can tell...

--

Outdoor thermometer placement
 

On 12/28/2015 8:32 AM, dpb wrote:
On 12/27/2015 4:40 PM, Don Y wrote:
On 12/27/2015 8:45 AM, dpb wrote:
On 12/27/2015 8:24 AM, Don Y wrote:
I can't seem to get this right. : Can't put it on the
roof with the other sensors as the deliberate exposure that
the roof affords those others interferes with the accuracy
of the temperature reported.

And, mounting it on the back porch ("up" out of the way)
shades it from direct sunlight but "keeps it warm" in the
colder weather due to heat trapped by the roof of the porch
(the same roof that *shades* it from the Sun).

So, it seems like the trick is to find shade without an
"overhead covering"? (contradiction in terms??)

I'll try the porch -- but much closer to the ground (farther
from the heat-trapping ceiling)?

You've got a special situation; if you're serious about grove
protection I'd
suggest getting in touch w/ the UofFL citrus folk--

grin Not a "grove", just half a dozen trees.

There's only so much we can realistically do; can't deploy smudge pots
as there are too many structures nearby; can't deploy fans as the trees
aren't arranged in a "grove" (we'd need several small fans, instead).

We opt to cover the trees and use small heat sources to help encourage
convective air flow (has to work in case it's also raining).

I've covetously eyed the "blow up figures" that folks put out for
holiday decorations thinking that I might be able to repurpose the
fans used in them. They *should* be able to tolerate rain, right?

OTOH, they are covered by a large inflatable fabric sack so I'm
not sure how well they actually fare in a downpour! (do people
actually have them inflated when its raining??)

The more practical solution is to move to higher ground farther
from the wash.

Or, stop growing fruit that doesn't like the weather!! :

[I've repeatedly threatened SWMBO that when the next REALLY cold
spell comes through and whacks the trees, I'll use them in the
smoker!! : ]

I've not been to grandparents' old place in TX Valley in years to know what
they now use (of course, it's two-three generations removed from grandparents
now) but for temp measurement I'd think you'd get by pretty nicely with just a
covered box near where you really need the detail info; as you point out if
you're really after that local micro-difference to protect individual tree(s)
it may not be enough unless you go for it in an all or nothing fashion whenever
you do get an indication (likely the most reasonable alternative). But, as
another I think noted, I've got a Davis Instruments weather station that seems
to be quite accurate simply with the sun shielding they come with "out of the
box" -- it sits out in the midday sun in SW KS at 100+ F w/o measuring
ridiculously high temps that occur from directly-exposed thermometers.

The standard thermometer on the north side of the house at the top of the porch
also has always seemed pretty good -- it's 8' or so, roughly from actual
outside wall of the house so the heating effects don't seem very influential as
far as can tell...

Radiate heat from the (masonry) house isn't the problem, IMO.
Rather, it is the heat trapped under the roofline that elevates
the temperature registered by the thermometer/sensor.

I would like to come up with a "solution" that others can
recreate (as I assume others will be interested in much of
the technology that I've developed -- and I'm not interested in
going into manufacturing! : )

COTS "weather stations", IME, are just "curiosities". They give
the user/owner a sense of what the weather is like -- without having
to be precise (note "precise" and "accurate" have different technical
meanings).

E.g., an indoor thermometer doesn't have to be accurate at all!
Do you *really* know if it is 68F in the house? 71? What's
the temperature at the other end of the hallway? In the kitchen?
etc.

All you want from the "thermostat" is to keep the temperature AT
a particular point -- and, some way of referring to that point
(we could call it "foogle" just as easily as "68") as well as
points ABOVE and BELOW ("elgar" is just below "foogle" and "gismatch"
is just above! : )

OTOH, if you know that a particular fruit is hardy to 32F (or 28F),
then you don't want to play guessing games wondering if 32 is
"elgar", "foogle" or "gismatch"!

You also want to know the *actual* relationship between these so
you can perform reliable mathematical operations on them: "How much
energy do I have to expend to create a local "foogle" microclimate
when the outdoor temperature is "elgar"? Or, "dingbrill"? At which
point will I no longer be able to influence the microclimate based on
these calculations??

[Someone with the sort of interest I'm concerned about will be
willing to sort out *proper* placement of a sensor instead of
just relying on what's convenient]

Outdoor thermometer placement
 

On 12/28/2015 11:54 AM, Don Y wrote:
....

OTOH, if you know that a particular fruit is hardy to 32F (or 28F),
then you don't want to play guessing games wondering if 32 is
"elgar", "foogle" or "gismatch"!

You also want to know the *actual* relationship between these so
you can perform reliable mathematical operations on them: "How much
energy do I have to expend to create a local "foogle" microclimate
when the outdoor temperature is "elgar"? Or, "dingbrill"? At which
point will I no longer be able to influence the microclimate based on
these calculations??

[Someone with the sort of interest I'm concerned about will be
willing to sort out *proper* placement of a sensor instead of
just relying on what's convenient]

Well, if you're really thinking you're going to get into it in that
depth, then there's a _ton_ of research already done and a large
fraction of it illustrates that simply knowing air temperature (no
matter how accurately) ain't _nearly_ enough to reliably predict damage.

--

Outdoor thermometer placement
 

On 12/28/2015 11:41 AM, dpb wrote:
On 12/28/2015 11:54 AM, Don Y wrote:
....

OTOH, if you know that a particular fruit is hardy to 32F (or 28F),
then you don't want to play guessing games wondering if 32 is
"elgar", "foogle" or "gismatch"!

You also want to know the *actual* relationship between these so
you can perform reliable mathematical operations on them: "How much
energy do I have to expend to create a local "foogle" microclimate
when the outdoor temperature is "elgar"? Or, "dingbrill"? At which
point will I no longer be able to influence the microclimate based on
these calculations??

[Someone with the sort of interest I'm concerned about will be
willing to sort out *proper* placement of a sensor instead of
just relying on what's convenient]

Well, if you're really thinking you're going to get into it in that depth, then
there's a _ton_ of research already done and a large fraction of it illustrates
that simply knowing air temperature (no matter how accurately) ain't _nearly_
enough to reliably predict damage.

Correct. That's why I also note wind speed/direction, barometric pressure,
solar radiation along with azimuth/elevation, dew point, etc. I'm not
looking for a "toy" that just throws numbers at a casual user/hobbyist
but, rather, a genuine control system! : The extent of control depending
on how much the user is willing to "invest" in instrumentation.

Outdoor thermometer placement
 

On Mon, 28 Dec 2015 10:54:56 -0700, Don Y
wrote:

On 12/28/2015 8:32 AM, dpb wrote:
On 12/27/2015 4:40 PM, Don Y wrote:
On 12/27/2015 8:45 AM, dpb wrote:
On 12/27/2015 8:24 AM, Don Y wrote:
I can't seem to get this right. : Can't put it on the
roof with the other sensors as the deliberate exposure that
the roof affords those others interferes with the accuracy
of the temperature reported.

And, mounting it on the back porch ("up" out of the way)
shades it from direct sunlight but "keeps it warm" in the
colder weather due to heat trapped by the roof of the porch
(the same roof that *shades* it from the Sun).

So, it seems like the trick is to find shade without an
"overhead covering"? (contradiction in terms??)

I'll try the porch -- but much closer to the ground (farther
from the heat-trapping ceiling)?

You've got a special situation; if you're serious about grove
protection I'd
suggest getting in touch w/ the UofFL citrus folk--

grin Not a "grove", just half a dozen trees.

There's only so much we can realistically do; can't deploy smudge pots
as there are too many structures nearby; can't deploy fans as the trees
aren't arranged in a "grove" (we'd need several small fans, instead).

We opt to cover the trees and use small heat sources to help encourage
convective air flow (has to work in case it's also raining).

I've covetously eyed the "blow up figures" that folks put out for
holiday decorations thinking that I might be able to repurpose the
fans used in them. They *should* be able to tolerate rain, right?

OTOH, they are covered by a large inflatable fabric sack so I'm
not sure how well they actually fare in a downpour! (do people
actually have them inflated when its raining??)

The more practical solution is to move to higher ground farther
from the wash.

Or, stop growing fruit that doesn't like the weather!! :

[I've repeatedly threatened SWMBO that when the next REALLY cold
spell comes through and whacks the trees, I'll use them in the
smoker!! : ]

I've not been to grandparents' old place in TX Valley in years to know what
they now use (of course, it's two-three generations removed from grandparents
now) but for temp measurement I'd think you'd get by pretty nicely with just a
covered box near where you really need the detail info; as you point out if
you're really after that local micro-difference to protect individual tree(s)
it may not be enough unless you go for it in an all or nothing fashion whenever
you do get an indication (likely the most reasonable alternative). But, as
another I think noted, I've got a Davis Instruments weather station that seems
to be quite accurate simply with the sun shielding they come with "out of the
box" -- it sits out in the midday sun in SW KS at 100+ F w/o measuring
ridiculously high temps that occur from directly-exposed thermometers.

The standard thermometer on the north side of the house at the top of the porch
also has always seemed pretty good -- it's 8' or so, roughly from actual
outside wall of the house so the heating effects don't seem very influential as
far as can tell...

Radiate heat from the (masonry) house isn't the problem, IMO.
Rather, it is the heat trapped under the roofline that elevates
the temperature registered by the thermometer/sensor.

I would like to come up with a "solution" that others can
recreate (as I assume others will be interested in much of
the technology that I've developed -- and I'm not interested in
going into manufacturing! : )

COTS "weather stations", IME, are just "curiosities". They give
the user/owner a sense of what the weather is like -- without having
to be precise (note "precise" and "accurate" have different technical
meanings).

E.g., an indoor thermometer doesn't have to be accurate at all!
Do you *really* know if it is 68F in the house? 71? What's
the temperature at the other end of the hallway? In the kitchen?
etc.

All you want from the "thermostat" is to keep the temperature AT
a particular point -- and, some way of referring to that point
(we could call it "foogle" just as easily as "68") as well as
points ABOVE and BELOW ("elgar" is just below "foogle" and "gismatch"
is just above! : )

OTOH, if you know that a particular fruit is hardy to 32F (or 28F),
then you don't want to play guessing games wondering if 32 is
"elgar", "foogle" or "gismatch"!

You also want to know the *actual* relationship between these so
you can perform reliable mathematical operations on them: "How much
energy do I have to expend to create a local "foogle" microclimate
when the outdoor temperature is "elgar"? Or, "dingbrill"? At which
point will I no longer be able to influence the microclimate based on
these calculations??

[Someone with the sort of interest I'm concerned about will be
willing to sort out *proper* placement of a sensor instead of
just relying on what's convenient]
Have you tried the chunk of 6 inch plastic pipe??
You get a chimey effect that moves the sir through the pipe when the
sun shines - negating any radiant heat absoption, you get full time
shade, and no heat entrapment. Put it on a pole out close to the
trees. It will be about the most accurate temperature record you can
get, across all variables. Mount the temp sensor in the middle of the
pipe. 2 or 3 feet long is adequate - longer won't hurt

Outdoor thermometer placement
 

On 12/28/2015 12:52 PM, Don Y wrote:
On 12/28/2015 11:41 AM, dpb wrote:
On 12/28/2015 11:54 AM, Don Y wrote:
....

OTOH, if you know that a particular fruit is hardy to 32F (or 28F),
then you don't want to play guessing games wondering if 32 is
"elgar", "foogle" or "gismatch"!

You also want to know the *actual* relationship between these so
you can perform reliable mathematical operations on them: "How much
energy do I have to expend to create a local "foogle" microclimate
when the outdoor temperature is "elgar"? Or, "dingbrill"? At which
point will I no longer be able to influence the microclimate based on
these calculations??

[Someone with the sort of interest I'm concerned about will be
willing to sort out *proper* placement of a sensor instead of
just relying on what's convenient]

Well, if you're really thinking you're going to get into it in that
depth, then
there's a _ton_ of research already done and a large fraction of it
illustrates
that simply knowing air temperature (no matter how accurately) ain't
_nearly_
enough to reliably predict damage.

Correct. That's why I also note wind speed/direction, barometric pressure,
solar radiation along with azimuth/elevation, dew point, etc. I'm not
looking for a "toy" that just throws numbers at a casual user/hobbyist
but, rather, a genuine control system! : The extent of control depending
on how much the user is willing to "invest" in instrumentation.

Much more expense will be involved in the mitigating devices than the
measurement, probably by orders of magnitude. What, specifically, do
you think you can physically control?

While done most specifically for CA, it has much general bearing --

biomet.ucdavis.edu/frostprotection/Principles%20of%20Frost%20Protection/PFPlong/PFPlong.pdf

As noted, all this will have been well developed in FL as well; you're
trying to reinvent the wheel it seems.

--