Vue roof install

[mickopla]

With the summer here in name only i might add in my location in Ireland we have had a few warm days. My Vue is installed on the back of my House as can be seen in the pic. Ideally how high should the station be away from the roof to stop it reading too high on a warm day. Currently its about 5 feet above. Any advice would be appreciated.

[xykotik]

Is it stored heat re-radiating from the clay-tile roof that concerns you?  Others with more experience may have better advice, but mine is about 6-feet above a composite-asphalt roof (appx 30-feet above a flowerbed on south-end of house) and my high/low numbers are good day and night (so far, since January installation).

[dalecoy]

... My Vue is installed on the back of my House as can be seen in the pic. Ideally how high should the station be away from the roof to stop it reading too high on a warm day. Currently its about 5 feet above. Any advice would be appreciated.

Well, first, why do you think it's reading too high?   And why do you believe it's due to distance from the roof, etc.?

If you are comparing against some other "official" station, try looking at the difference on a cloudy day, and the difference on a sunny day.  That will tell you something.  Also, consider where the "official" station is taking its data.  Chances are it's perhaps 4 ft. above a grassy surface.

You are measuring the ambient temperature at the location of the Vue.  Raising it a bit higher might (or might not) make the temperature lower, but it will still be the temperature above your roof - not the temperature in your garden.

Also, although you didn't ask - and it's hard to tell from the photo - but I strongly suspect that your roof has a big effect in making your wind direction and speed readings be "incorrect".  That is, you're measuring the direction and speed where the Vue is mounted, but that might be very different from what you would measure in "clear air".  Of course, the wind measurements where it's mounted may be "better" than if you mounted it in your garden. 

Of course, maybe you don't have a garden.  .....

[mickopla]

... My Vue is installed on the back of my House as can be seen in the pic. Ideally how high should the station be away from the roof to stop it reading too high on a warm day. Currently its about 5 feet above. Any advice would be appreciated.

Well, first, why do you think it's reading too high?   And why do you believe it's due to distance from the roof, etc.?

If you are comparing against some other "official" station, try looking at the difference on a cloudy day, and the difference on a sunny day.  That will tell you something.  Also, consider where the "official" station is taking its data.  Chances are it's perhaps 4 ft. above a grassy surface.

You are measuring the ambient temperature at the location of the Vue.  Raising it a bit higher might (or might not) make the temperature lower, but it will still be the temperature above your roof - not the temperature in your garden.

Also, although you didn't ask - and it's hard to tell from the photo - but I strongly suspect that your roof has a big effect in making your wind direction and speed readings be "incorrect".  That is, you're measuring the direction and speed where the Vue is mounted, but that might be very different from what you would measure in "clear air".  Of course, the wind measurements where it's mounted may be "better" than if you mounted it in your garden. 

Of course, maybe you don't have a garden.  .....

I'm taking my comparison readings from another sensor that i have located in my garden. That sensor is located 5 foot off the ground and shaded. I think some heat from the roof is raising temps by 1c in very sunny conditions.
With regards wind readings they are important to me and when i had the Vue located in the garden winds were miles from being accurate. I had to raise it higher and comparing my wind readings with other local stations they are fairly accurate direction and speed wise.
Unfortunately there is no perfect location for the Vue. No matter where its put something is going to be out. Its just about a compromise. Lesson learned for my next Station purchase in the future.

[dalecoy]

OK, so you clearly know what's going on, and understand the tradeoffs.

"I think some heat from the roof is raising temps by 1c in very sunny conditions"

Then I would recommend two things, if you can do them?

1.  Go up another 4 feet or so.  That will reduce the roof effect, and also (perhaps only slightly) improve your wind measurements.

2.  Since you say "in very sunny conditions" (which is what I suspected), I am guessing that you are getting quite a bit of sun reflection from the roof.  That will tend to heat the bottom of the Vue.  If you can put some sort of circular shield a few inches below the Vue, that would reduce the effect.  The shield doesn't have to be anything fancy. 

[mickopla]

OK, so you clearly know what's going on, and understand the tradeoffs.

"I think some heat from the roof is raising temps by 1c in very sunny conditions"

Then I would recommend two things, if you can do them?

1.  Go up another 4 feet or so.  That will reduce the roof effect, and also (perhaps only slightly) improve your wind measurements.

2.  Since you say "in very sunny conditions" (which is what I suspected), I am guessing that you are getting quite a bit of sun reflection from the roof.  That will tend to heat the bottom of the Vue.  If you can put some sort of circular shield a few inches below the Vue, that would reduce the effect.  The shield doesn't have to be anything fancy. 

Sounds like great advice. Would the circular shield need to be made of any particular material? Both suggestions make sense and should help with both temp and wind readings i think. Something to do tomorrow so 

[dalecoy]

No particular material, except that I would advise that it not be a dark color. 

[mickopla]

No particular material, except that I would advise that it not be a dark color. 

Would it need to cover the entire iss or just the temp sensor?

[chief-david]

My Davis 6163 is on the roof of my school   tar and rock roof.  surrounded by cement.

I do not feel like it reads higher than anyone else around

http://weather.rms.rdale.org/about.htm

[dalecoy]

No particular material, except that I would advise that it not be a dark color. 

Would it need to cover the entire iss or just the temp sensor?

The idea is to sortof protect the entire bottom surface of the Vue from radiation coming off of the roof surface.  That radiation might be partially reflected sunlight on a sunny day, and/or the radiation from warm tiles. 

Illustration: Take an umbrella outside on a sunny day.  Stand near a wall that is exposed to the sun.  (a) Just stand there - you will feel warm on both sides of your body.  (b) open the umbrella and hold it between you and the sun - you will feel warmth radiating from the wall.  (c) hold the umbrella between you and the wall - you will feel less warmth from the wall.

So, if it were my installation, I would try to make the "radiation shield" as large as practical.  Say a foot or so in diameter?  And put it a few inches below the VUE, to allow air circulation. 

[mickopla]

No particular material, except that I would advise that it not be a dark color. 

Would it need to cover the entire iss or just the temp sensor?

The idea is to sortof protect the entire bottom surface of the Vue from radiation coming off of the roof surface.  That radiation might be partially reflected sunlight on a sunny day, and/or the radiation from warm tiles. 

Illustration: Take an umbrella outside on a sunny day.  Stand near a wall that is exposed to the sun.  (a) Just stand there - you will feel warm on both sides of your body.  (b) open the umbrella and hold it between you and the sun - you will feel warmth radiating from the wall.  (c) hold the umbrella between you and the wall - you will feel less warmth from the wall.

So, if it were my installation, I would try to make the "radiation shield" as large as practical.  Say a foot or so in diameter?  And put it a few inches below the VUE, to allow air circulation. 

Makes great sense what your saying. I would have to keep the shield below the Wind Vane though so it would end up more than a few inches away. I'm thinking of using a Foot Diameter plastic plant saucer as the shield. Hopefully will get around to doing the job in the next few days. Will report back results then. Thanks Dale for the great ideas.

[mickopla]

My Davis 6163 is on the roof of my school   tar and rock roof.  surrounded by cement.

I do not feel like it reads higher than anyone else around

http://weather.rms.rdale.org/about.htm

Maybe there is a better screen on your Vantage Pro Plus then on the Vue.

[dalecoy]

I would have to keep the shield below the Wind Vane though so it would end up more than a few inches away. I'm thinking of using a Foot Diameter plastic plant saucer as the shield. Hopefully will get around to doing the job in the next few days. Will report back results then. Thanks Dale for the great ideas.

Yes, sorry I wasn't clear.  I meant a few inches below the entire Vue, meaning a few inches below the wind vane.  That should not interfere with the accuracy of wind direction readings, assuming that whatever you use is relatively flat and symmetrical - like a plant saucer.

[Ugly Duckling]

1.  Go up another 4 feet or so.  That will reduce the roof effect, and also (perhaps only slightly) improve your wind measurements.

How high above the peak of roof does the sensor need to be to have accurate temp and wind measurements?

Many Happy Weather Changes,

Marci Anna

[dalecoy]

1.  Go up another 4 feet or so.  That will reduce the roof effect, and also (perhaps only slightly) improve your wind measurements.

How high above the peak of roof does the sensor need to be to have accurate temp and wind measurements?

There is absolutely no way to answer that question.  Regarding wind - it depends on the roof shape, height, walls, terrain, surrounding area, adjacent features, etc.

Regarding temperature - it depends on the model (Vue of VP), radiation shield, is it equipped with a FARS, roof material, roof shape, etc.  And regarding temperature, the measurement above the roof will "never" be the same as the measurement in your garden.

My recommendations to mickopla were based on making measurements better with a Vue above a tile roof, given what I could guess from the photographs provided.  Regardless of that, the measurements aren't going to be "accurate" (if "accurate" means "identical to what they would be if the installation were standard).  But they will be accurate for the actual location.

[mcneese832000]

I have my vue on the edge of my white tin carport about 4.5 feet up and my numbers are very consistent with the NWS forecast center a few miles away.

[Ugly Duckling]

Maybe there is a better screen on your Vantage Pro Plus then on the Vue.

That Vue is so cool! I have one too sorta. At least I've been charged for one. It's sitting at UPS waiting to be delivered tomorrow. I can't wait to get it set up.

I'm excited!

Many Happy Weather Changes,

Marci Anna

[dalecoy]

Maybe there is a better screen on your Vantage Pro Plus then on the Vue.

That Vue is so cool! I have one too sorta. At least I've been charged for one. It's sitting at UPS waiting to be delivered tomorrow. I can't wait to get it set up.

I'm excited!

Many Happy Weather Changes,

Marci Anna

So, did you order a logger to go with it?

[Ugly Duckling]

Maybe there is a better screen on your Vantage Pro Plus then on the Vue.

That Vue is so cool! I have one too sorta. At least I've been charged for one. It's sitting at UPS waiting to be delivered tomorrow. I can't wait to get it set up.

I'm excited!

Many Happy Weather Changes,

Marci Anna

So, did you order a logger to go with it?

Yep

Many Happy Weather Changes,

Marci Anna

[dalecoy]

I guess we'll eventually find out which variety.

[xykotik]

Maybe there is a better screen on your Vantage Pro Plus then on the Vue.

That Vue is so cool! I have one too sorta. At least I've been charged for one. It's sitting at UPS waiting to be delivered tomorrow. I can't wait to get it set up.

I'm excited!

Many Happy Weather Changes,

Marci Anna

And you have downloaded (from davis) and memorized the setup guides for the Vue and the logger by now.  Right?  We fully expect a narrated video of you opening the box and installing the thing on YouTube by the end of the day.