Outdoor thermometer placement

Page 2 of 3  
On 12/28/2015 9:59 PM, Snuffy "Hub Cap" McKinney wrote:

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!
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sun, 27 Dec 2015 14:33:56 -0700, Don Y

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!!

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Wednesday, December 30, 2015 at 2:04:12 AM UTC-5, Micky wrote:

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.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Wed, 30 Dec 2015 07:32:46 -0800 (PST), DerbyDad03

True.

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

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.

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.

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.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Thursday, December 31, 2015 at 5:21:11 AM UTC-5, Micky wrote:

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.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Thu, 31 Dec 2015 04:59:30 -0800 (PST), DerbyDad03

No, I don't, but I'll grant that part is a matter of opinion.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

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.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sun, 27 Dec 2015 07:49:30 -0700, Don Y

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.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sun, 27 Dec 2015 07:49:30 -0700, Don Y

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

It's also darkest just before the dawn! So I hear.
http://www.phrases.org.uk/meanings/darkest-hour.html
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 12/27/2015 8:39 AM, 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.
--
Maggie

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
| 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. :)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sun, 27 Dec 2015 20:32:02 -0500, "Mayayana"

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Luddite!
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 12/27/2015 09:24 AM, Don Y wrote:

You could blow an afternoon building a solar shield
http://wxqa.com/shields.html
or you could skip the tinkering and just go to ObamaWeather at
http://w1.weather.gov/obhistory/KDTW.html
and punch in your local ICAO airport code.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 12/27/2015 7:54 AM, Leisure Suit Larry wrote:

Yeah, but in order to not ADD to the error, they tend to need to be *large*, well vented, etc.

Ever hear of the term "microclimate"? :> The airport weather ONLY applies to the airport, here. Different elevation, different air flow (not wind!) patterns, etc. Every TV station reports a different set of conditions, based on their *local* area (which part of town).
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)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

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.....
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 12/27/2015 9:24 AM, Don Y wrote:

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.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 12/27/2015 8:03 AM, Ed Pawlowski wrote:

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!).

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 12/27/2015 8:24 AM, Don Y wrote:

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/>
--


Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 12/27/2015 8:45 AM, dpb wrote:

<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!! :> ]
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.