On 12/28/2015 12:44 PM, dpb wrote:
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?

I use environmental monitoring to bias the HVAC control algorithms
(compensating for losses/gains from exterior events; intelligently
determining whether to use evaporative cooling vs. refrigeration;
*anticipating* required control actions to achieve desired results),
to determine irrigation needs (transpirational losses); as well
as deciding when/if any local controls can benefit the vegetation
(fruit being *my* concern but others might be more interested
in their orchid collections, etc.).

Wrt the fruit trees, I can control air flow through the individual
trees, some local heat sources and "misting" (coating the trees with
a fine layer of ice).

I can also know when "all is lost" and not attempt further action
("wood" will be damaged).

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.

How many folks do you know who can do that IN THEIR BACK YARD?

Which paragraph discusses impact of solar radiation on heat gain in a
residence? Or, "comfort factor" compensation for air infiltration?

Where does it tell me the economic tradeoff of using evaporative cooling
on a particular day vs. refrigeration? Or, the penalty of using refrigeration
*after* evaporative cooling?

Where does it tell me about the (affordable) COTS control system that I
can PURCHASE to do these things?

I'd *really* not like to have to "reinvent the wheel" so would greatly
appreciate those pointers! :

On 12/28/2015 1:24 PM, wrote:
On Mon, 28 Dec 2015 10:54:56 -0700, Don Y
....

[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

The point is that there is no single-point measurement location that
suffices; it depends on the type of event (advection vis a vis
radiation, eg) , whether there is and how heavy an inversion later
exists, and a zillion other details.

It's been studied extensively by all the research organizations in the
citrus-producing areas, both public and private if he'd just make use of
that body of knowledge instead of seemingly thinking he's the first to
have thought of it.

In general, a 6-ft measurement, another at tree-top height and about 40'
if higher than the canopy is generally what is typically done in
commercial groves. How much other detail they use for actual leaf and
bark temperatures and such is mostly dependent upon how valuable the
crop is.

For a hobbyist or noncommercial it likely isn't practical anyway owing
to the cost of the mitigating effects required to do anything effective,
anyway, other than if can cover a few small trees or do a minimal amount
of sprinkling or the like. It's hardly likely the fuel bill for heaters
will make it cost-effective for a homeowner with a few trees unless
they've just got resources to burn (so to speak).

The cost for monitoring these days is pretty much peanuts; it's the
downstream costs that are the killer for anybody except the commercial
grower.

--

On 12/28/2015 12:24 PM, wrote:
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

I don't think that would be a viable option for most folks.
It's one thing to have to make an effort to "put it in the right place";
another thing entirely to have to locate something that is that physically
large and visually unappealing! Likewise, I need to come up with
a smaller "rain detector"... one that isn't as visually obtrusive
(and, ideally, requires less maintenance).

[People don't want to make "careers" out of this sort of thing! When
was the last time you calibrated your household thermostat?]

I'm going to investigate radiation shields and see if I can come up
with an approach that is easily reproduced that affords greater
flexibility in siting. I can make a bunch of sensors, calibrate
them (to each other) and set them in different shields located in the
same general area. Take data, then relocate the group to other
locations and see how they perform compared to each other, etc.

I'll talk to someone at the university and see what they say
about setting up a "control" against which to measure them.
That way, just let a machine do all the data collection in a
more repeatable fashion instead of playing wack-a-mole with
different sensors, placements, etc.

On 12/28/2015 12:58 PM, dpb wrote:

It's been studied extensively by all the research organizations in the
citrus-producing areas, both public and private if he'd just make use of that
body of knowledge instead of seemingly thinking he's the first to have thought
of it.

Sheer arrogance and ignorance on your part! As I said elsewhe

How many folks do you know who can do that IN THEIR BACK YARD?

Which paragraph discusses impact of solar radiation on heat gain in a
residence? Or, "comfort factor" compensation for air infiltration?

Where does it tell me the economic tradeoff of using evaporative cooling
on a particular day vs. refrigeration? Or, the penalty of using
refrigeration *after* evaporative cooling?

Where does it tell me about the (affordable) COTS control system that I
can PURCHASE to do these things?

I'd *really* not like to have to "reinvent the wheel" so would greatly
appreciate those pointers! :

So, please tell me -- and the rest of those reading -- exactly *who* has
"thought of it" before?!

I guess *your* problem is failing to understand that not all problems
*have* been "thought of before". Or, having too narrow a concept of
what you can actually *do* with "data" once you have it! It's a
relatively common problem: people who can't see past their own
experience...

On 12/28/2015 2:09 PM, Don Y wrote:
On 12/28/2015 12:58 PM, dpb wrote:

It's been studied extensively by all the research organizations in the
citrus-producing areas, both public and private if he'd just make use
of that
body of knowledge instead of seemingly thinking he's the first to have
thought
of it.

Sheer arrogance and ignorance on your part! As I said elsewhe

No, simply stating fact...and, as said, have quite a bit of family
experience in the citrus/truck farming "bidness" from the '30s and on w/
mother's side of the family in the TX valley...

How many folks do you know who can do that IN THEIR BACK YARD?

Not many which is why I said it generally ain't agonna' be practical...

Which paragraph discusses impact of solar radiation on heat gain in a
residence? Or, "comfort factor" compensation for air infiltration?

Where does it tell me the economic tradeoff of using evaporative cooling
on a particular day vs. refrigeration? Or, the penalty of using
refrigeration *after* evaporative cooling?

Where does it tell me about the (affordable) COTS control system that I
can PURCHASE to do these things?

Well, that's a completely different kettle o' fish than citrus grove
freeze protection which is all I had addressed...

I'd *really* not like to have to "reinvent the wheel" so would greatly
appreciate those pointers! :

So, please tell me -- and the rest of those reading -- exactly *who* has
"thought of it" before?!

I guess *your* problem is failing to understand that not all problems
*have* been "thought of before". Or, having too narrow a concept of
what you can actually *do* with "data" once you have it! It's a
relatively common problem: people who can't see past their own
experience...


I spent some 40 yr of engineering consulting doing data collection and
usage so I've a pretty good idea of what can be done w/ data...from
online coal ash and elemental analyzers to pulverized coal flow w/
acoustic noise inference via nonlinear processing of the chaotic (as
opposed to stationary stochastic) flow patterns to more conventional
vibration and such including online heat-rate performance monitoring for
fossil plants (much more related to your HVAC question albeit on a much
larger scale and with temperatures and pressures a little higher!

In the specific areas you've mentioned here I don't know offhand who's
done what; granted, but that wasn't what I thought you were interested
in as noted above.

While it's a reasonable conjecture, I'd venture 90% of homeowners will
get far more "bang for the buck" simply by adding insulation or the
other routine energy-efficiency changes than what could gain by dynamic
control such as you posit above.

Similar to the questions who can do serious control of freeze
mitigation in their backyard, how many houses have both evaporative
_and_ refrigerating cooling systems?

I'd still guess there's quite a bit of useful work having been done and
for your purposes worrying about a degree or two of error in that
external temperature is also a case of misplaced concern since as you
mention it isn't that critical to a precise degree what an internal
temperature is if it's somewhere in the mid-range of the comfort zone
most folks will be happy enough...

https://www.ashrae.org/resources--publications/bookstore/thermal-comfort-tool?utm_source=promotion&utm_medium=landingpage&u tm_campaign=86179&utm_term=86179&utm_content=86179

As for the predictions you're talking about, application of the load
calculations manual would basically provide all the information required
to evaluate alternatives as far as input costs, etc., if applied to a
specific structure and installed systems as opposed to the sizing
calculation itself. But, all the basic heat loss/input computations are
outlined to do it...

I'm sure there are optimizing controls already for commercial buildings
altho not my area of direct expertise but again I doubt it'll be found
to be cost-beneficial to this degree for single-family residential
applications. Beyond the thermostat runback at night and converting
old, low-efficiency furnaces/boilers to higher-efficiency units and the
aforementioned closing up of other heat/cooling loss venues, the
remainder is, in my estimation, likely to be found to be in the noise
level of actual cost/benefit.

--

On 12/28/2015 2:13 PM, dpb wrote:

Which paragraph discusses impact of solar radiation on heat gain in a
residence? Or, "comfort factor" compensation for air infiltration?

Where does it tell me the economic tradeoff of using evaporative cooling
on a particular day vs. refrigeration? Or, the penalty of using
refrigeration *after* evaporative cooling?

Where does it tell me about the (affordable) COTS control system that I
can PURCHASE to do these things?

Well, that's a completely different kettle o' fish than citrus grove freeze
protection which is all I had addressed...

Knowing what to do and having something that will actually *do* it
are entirely different things! You can wire an on/off switch to your
furnace and keep the interior of your home at a comfortable temperature...
by flipping it on and off throughout the course of the day!

Not many people would opt for that form of control, though! So,
someone makes an AFFORDABLE device that does this FOR you and
suddenly it's commonplace!

I'd *really* not like to have to "reinvent the wheel" so would greatly
appreciate those pointers! :

So, please tell me -- and the rest of those reading -- exactly *who* has
"thought of it" before?!

I guess *your* problem is failing to understand that not all problems
*have* been "thought of before". Or, having too narrow a concept of
what you can actually *do* with "data" once you have it! It's a
relatively common problem: people who can't see past their own
experience...

I spent some 40 yr of engineering consulting doing data collection and usage so
I've a pretty good idea of what can be done w/ data...from online coal ash and
elemental analyzers to pulverized coal flow w/ acoustic noise inference via
nonlinear processing of the chaotic (as opposed to stationary stochastic) flow
patterns to more conventional vibration and such including online heat-rate
performance monitoring for fossil plants (much more related to your HVAC
question albeit on a much larger scale and with temperatures and pressures a
little higher!

And *no one* commercially addresses all of the areas that I've mentioned
with an integrated, affordable controller. Because the "citrus growers"
don't give a rat's ass about interior HVAC controls; and the HVAC control
developers don't give a rats ass about citrus protection, cactus protection,
orchid protection, etc. The folks who designed the controller for our
evaporative cooler cared nothing about the controls for the furnace
(i.e., added their own indoor temperature sensor despite the fact that
the air conditioner *and* furnace already have this!).

No one deals with anything outside their own little microcosm of
experience.

So, you'd end up with N different systems (assuming you could find
COTS systems to do these things!)

In the specific areas you've mentioned here I don't know offhand who's done
what; granted, but that wasn't what I thought you were interested in as noted
above.

I notice you didn't mention anything about HVAC despite my reference to it
early in the thread:
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.

While it's a reasonable conjecture, I'd venture 90% of homeowners will get far
more "bang for the buck" simply by adding insulation or the other routine
energy-efficiency changes than what could gain by dynamic control such as you
posit above.

Actually, you get a lot of benefit (energy saving and comfort) by
putting smarts into a home thermostat. SWMBO opts for an open window
despite the fact that the outdoor temperature is 30-ish at night.
Neither of us wants the house warm while sleeping. OTOH, if I'm up
late working, I don't want it *cold*. Both of us want it warm
*before* we wake up -- yet having it warm too soon before rising
would be wasteful of energy.

Adding insulation to a building after it's been built isn't always possible.
E.g., our walls are cement block. Adding insulation would require
adding a layer of styrofoam outside the block and reapplying the stucco
to that surface. Or, framing *in* the interior walls to create additional
space for fiberglass bats or blown in.

Adding ceiling in the ceiling is essentially impossible as the roof
is 9" above the ceiling -- and can't be "filled solid" or it won't
be able to breathe. So, unless I wanted to incur serious expenses
to remodel the house, *smart* control of the HVAC is a far easier
way to save money. *And*, can be applied to my neighbor's house
(and HIS neighbor's house, etc.) just as easily/econmically as here!

I.e., the solution SCALES well!

Likewise, a solution to addressing the citrus problems we encounter
in our little microclimate would benefit everyone in the neighborhood
with citrus trees or other "frost tender" plants. E.g., the Saguaros
also don't like the cold; and, with a 75 year investment in a plant
(if it has "arms", it's 75 years old or more), you don't want to
lose it just because of a weather event.

Similar to the questions who can do serious control of freeze mitigation in
their backyard, how many houses have both evaporative _and_ refrigerating
cooling systems?

Here? Probably 30%. There has been some talk of banning evapporative
coolers as water is precious but the cost of refrigeration makes that
as the EXCLUSIVE form of cooling impractical for folks with limited means.

(recall my comment seeing past their own experience?)

I'd still guess there's quite a bit of useful work having been done and for
your purposes worrying about a degree or two of error in that external
temperature is also a case of misplaced concern since as you mention it isn't
that critical to a precise degree what an internal temperature is if it's
somewhere in the mid-range of the comfort zone most folks will be happy enough...

https://www.ashrae.org/resources--publications/bookstore/thermal-comfort-tool?utm_source=promotion&utm_medium=landingpage&u tm_campaign=86179&utm_term=86179&utm_content=86179

It's not just "perception". Take the leftmost two digits of your income and
figure out your effective hourly wage. How happy would you be if your
employer compensated you based on that? On average, you'd be cheated out
of $500 for every 2000 hours (1 year) worked.

Hence precision is more important than accuracy.

OTOH, precision without accuracy doesn't help for things that have
actual physical limits: plants die at fixed temperatures regardless
of how *precise* the temperature measurement.

A precise but inaccurate temperature measurement will be reflected in
additional inaccuracy for any other measurements/calculations on which
it is relied.

As for the predictions you're talking about, application of the load
calculations manual would basically provide all the information required to
evaluate alternatives as far as input costs, etc., if applied to a specific
structure and installed systems as opposed to the sizing calculation itself.
But, all the basic heat loss/input computations are outlined to do it...

I'm sure there are optimizing controls already for commercial buildings altho
not my area of direct expertise but again I doubt it'll be found to be
cost-beneficial to this degree for single-family residential applications.

Exactly. The *controls* are too expensive. But, the algorithms and
instrumentation are not.

A simple test to see if it's rained recently makes a big difference
in the amount of water used by an otherwise dumb/naive irrigation
system! (why water if it rained yesterday? Or, if it is RAINING
TODAY??)

An irrigation controller that considers evaporative and transpirational
losses wouldn't foolishly water during the hot part of the day as
~40% of the water is lost!

These sorts of things are reasonably well known -- yet frequently
ignored by the folks charged with setting the "dumb" controllers.

Beyond the thermostat runback at night and converting old, low-efficiency
furnaces/boilers to higher-efficiency units and the aforementioned closing up
of other heat/cooling loss venues, the remainder is, in my estimation, likely
to be found to be in the noise level of actual cost/benefit.

What do you do when the house is empty but it's daytime? Keep it nice and
warm -- in case someone comes home from work, early? Do you connect the
HVAC to your telephone/internet and REQUIRE the homeowner to "phone home"
prior to arriving and "turn up the heat" so its warm (cool) when they
walk in the door? Should *they* look at the current weather conditions
and make the decision as to WHEN they should tweek the temperature
setpoint? Perhaps query the house to see what the actual indoor
temperature is, the outdoor temperature, wind speed, etc. and make
a "gut feel" calculation? Or, maybe just wait until they get home
and manually make the change at that time? Perhaps opting not to
let the house deviate too far from that desired temperature because they
don't want to have to wait a long time for it to return to their
"comfort zone"?

What if they have forced air vs. hot water heat at their new residence?
Should they relearn these "gut feel" calculations to reflect the
different control actions of their new HVAC plant? How soon before
retiring/arising should they adjust the AC/furnace/heatpump in the bedroom
area as opposed to the living areas? (multizone control)

Don't look at *your* experience(s) and extrapolate from that unless you're
aware of what other folks' experiences are!

"Don Y" wrote in message ...
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"]

I was interested in the temp difference at various roof vents once when installing an attic fan. Went to the dollar store and picked out 12 that were reading the same in the store and set them outside of the vents so I could read them from the ground. Then checked them with binoculars ever couple of hours. This was on a hot summer day and all were in the shade of the eaves. I didn't see more than a couple of degrees difference between the sunny & shady sides of the house.

On 12/28/2015 9:59 PM, Snuffy "Hub Cap" McKinney wrote:
"Don Y" wrote in message
...
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"]

I was interested in the temp difference at various roof vents once when
installing an attic fan. Went to the dollar store and picked out 12 that
were reading the same in the store and set them outside of the vents so I
could read them from the ground. Then checked them with binoculars ever
couple of hours. This was on a hot summer day and all were in the shade of
the eaves. I didn't see more than a couple of degrees difference between
the sunny & shady sides of the house.

Yet you notice I saw a 20 degree rise in the course of a couple of minutes
by moving mine from the "sheltered porch" to the "open yard" 12 feet away?
I could actually *watch* the indicator move every few seconds!

20 degrees is not a trivial error!

On Sun, 27 Dec 2015 14:33:56 -0700, Don Y
wrote:

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.

Not if you put a little awning over them.

IIUC white on the top and black on the bottom, but any color will do
most of it.

The only diff. between the shady side of the house and the sunny side
is the shade!!

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"]

On Wednesday, December 30, 2015 at 2:04:12 AM UTC-5, Micky wrote:
On Sun, 27 Dec 2015 14:33:56 -0700, Don Y
wrote:

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.

Not if you put a little awning over them.

IIUC white on the top and black on the bottom, but any color will do
most of it.

The only diff. between the shady side of the house and the sunny side
is the shade!!


Not true.

The sun can heat up the surrounding area and surfaces and well as cause
evaporation, completely changing the "local" climate.

A "little awning" over a sensor to protect it from the sun is not going
to completely compensate for the temperature difference caused by the sun's
influence on the surrounding area.

Try a protected sensor over a sun drenched blacktop driveway and a protected
sensor over a sun drenched lawn or even a sun drenched pond. Tell me if
they report the same temperature.

On Wed, 30 Dec 2015 07:32:46 -0800 (PST), DerbyDad03
wrote:

On Wednesday, December 30, 2015 at 2:04:12 AM UTC-5, Micky wrote:
On Sun, 27 Dec 2015 14:33:56 -0700, Don Y
wrote:

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.

Not if you put a little awning over them.

IIUC white on the top and black on the bottom, but any color will do
most of it.

The only diff. between the shady side of the house and the sunny side
is the shade!!


Not true.

True.

The sun can heat up the surrounding area and surfaces and well as cause
evaporation, completely changing the "local" climate.

But then if that is happening near the tree, that is the temperature
near the tree.

A "little awning" over a sensor to protect it from the sun is not going
to completely compensate for the temperature difference caused by the sun's
influence on the surrounding area.

The goal IS to measure the temperature of the surrounding area. All
the awning is for is to keep the direct sunlight from making the
thermometer too hot, as in Don's example of it reading 20 degrees
higher after he carried it in the bright sun for 20 feet.

Try a protected sensor over a sun drenched blacktop driveway and a protected

With the driveway you'd probably have to protect it from heat
radiating from the blacktop. I assume his trees are planted in the
middle of a grassy area, or an area with other vegatation.

sensor over a sun drenched lawn or even a sun drenched pond. Tell me if
they report the same temperature.

Of course not but it doesn't matter. The goal is to measure the
temperature by the trees, which is why you put the thermometer(s) by
the trees.

On Thursday, December 31, 2015 at 5:21:11 AM UTC-5, Micky wrote:
On Wed, 30 Dec 2015 07:32:46 -0800 (PST), DerbyDad03
wrote:

On Wednesday, December 30, 2015 at 2:04:12 AM UTC-5, Micky wrote:
On Sun, 27 Dec 2015 14:33:56 -0700, Don Y
wrote:

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.

Not if you put a little awning over them.

IIUC white on the top and black on the bottom, but any color will do
most of it.

The only diff. between the shady side of the house and the sunny side
is the shade!!


Not true.

True.

The sun can heat up the surrounding area and surfaces and well as cause
evaporation, completely changing the "local" climate.

But then if that is happening near the tree, that is the temperature
near the tree.

A "little awning" over a sensor to protect it from the sun is not going
to completely compensate for the temperature difference caused by the sun's
influence on the surrounding area.

The goal IS to measure the temperature of the surrounding area. All
the awning is for is to keep the direct sunlight from making the
thermometer too hot, as in Don's example of it reading 20 degrees
higher after he carried it in the bright sun for 20 feet.

Try a protected sensor over a sun drenched blacktop driveway and a protected

With the driveway you'd probably have to protect it from heat
radiating from the blacktop. I assume his trees are planted in the
middle of a grassy area, or an area with other vegatation.

sensor over a sun drenched lawn or even a sun drenched pond. Tell me if
they report the same temperature.

Of course not but it doesn't matter. The goal is to measure the
temperature by the trees, which is why you put the thermometer(s) by
the trees.

I was simply responding to your comment that the only difference between sun
and shade is the shade. Even you seem to agree that that is not correct, based
on your latest response.

On Thu, 31 Dec 2015 04:59:30 -0800 (PST), DerbyDad03
wrote:

On Thursday, December 31, 2015 at 5:21:11 AM UTC-5, Micky wrote:
On Wed, 30 Dec 2015 07:32:46 -0800 (PST), DerbyDad03
wrote:

On Wednesday, December 30, 2015 at 2:04:12 AM UTC-5, Micky wrote:
On Sun, 27 Dec 2015 14:33:56 -0700, Don Y
wrote:

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.

Not if you put a little awning over them.

IIUC white on the top and black on the bottom, but any color will do
most of it.

The only diff. between the shady side of the house and the sunny side
is the shade!!


Not true.

True.

The sun can heat up the surrounding area and surfaces and well as cause
evaporation, completely changing the "local" climate.

But then if that is happening near the tree, that is the temperature
near the tree.

A "little awning" over a sensor to protect it from the sun is not going
to completely compensate for the temperature difference caused by the sun's
influence on the surrounding area.

The goal IS to measure the temperature of the surrounding area. All
the awning is for is to keep the direct sunlight from making the
thermometer too hot, as in Don's example of it reading 20 degrees
higher after he carried it in the bright sun for 20 feet.

Try a protected sensor over a sun drenched blacktop driveway and a protected

With the driveway you'd probably have to protect it from heat
radiating from the blacktop. I assume his trees are planted in the
middle of a grassy area, or an area with other vegatation.

sensor over a sun drenched lawn or even a sun drenched pond. Tell me if
they report the same temperature.

Of course not but it doesn't matter. The goal is to measure the
temperature by the trees, which is why you put the thermometer(s) by
the trees.

I was simply responding to your comment that the only difference between sun
and shade is the shade. Even you seem to agree that that is not correct, based
on your latest response.

No, I don't, but I'll grant that part is a matter of opinion.

Anywhere on the north side of a building that has a wall that is reasonably insulated and that has air flow should be satisfactory. Don't make a 6-day project out of a five minute task!!!

Don Y writes:
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)?

Stevenson Screen.

i had the same problem, especially when i lived in Las Vegas


life is [so] hard, isn't it?


you might try Multiple outdoor sensor locations

marc