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Davis vantage vue radiation shield not white enough? It looks light grey even at pictures on their website

Discussion specific to Davis weather stations
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I know i have to
Posts: 7
Joined: Sat 16 Jul 2022 2:03 pm
Weather Station: Davis Vantage vue
Operating System: Windows 10 Home
Location: Örebro, Sweden

Davis vantage vue radiation shield not white enough? It looks light grey even at pictures on their website

Post by I know i have to »

I'm wondering if painting the davis vantage vue radiation shield a pure white with no tones of black, blue or yellow which usually is the case will reduce heat buildup within the shield and therefore improve and flatten out solar spikes? My station is located 1,5m above grass surface and no obstacles within 6m so i don't get how the 2nd best weather station for private users have these faults.

Since the colour gray also has an albedo of 0,5-0,7 depending on the shade it must make quite a big difference if i paint it white which has an albedo of 0,8-0,9 aka 25% less radiation absorbed which is around 125w less heat from the sun during the time when the sun angle shines on the whole shield.

Has anyone tried painting the shield white and did it have any effect? The problem is only during daytime 10-18 so before and after that time my station and the nearest airport goes hand in hand basically.

Example from today during partly cloudy conditionshttp://www.bilddump.se/bilder/202208081 ... 22.173.png
freddie
Posts: 2421
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Re: Davis vantage vue radiation shield not white enough? It looks light grey even at pictures on their website

Post by freddie »

To me, your temperature graph looks reasonable - it is a typical trace for a day when the cloud sometimes covers the sun. You stand to gain more accuracy by aspirating your temperature screen - by setting up a fan that will keep an airflow blowing across the sensors and not allowing air to stagnate and remain stationary near the sensors.
Freddie
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I know i have to
Posts: 7
Joined: Sat 16 Jul 2022 2:03 pm
Weather Station: Davis Vantage vue
Operating System: Windows 10 Home
Location: Örebro, Sweden

Re: Davis vantage vue radiation shield not white enough? It looks light grey even at pictures on their website

Post by I know i have to »

freddie wrote: Mon 08 Aug 2022 4:11 pm To me, your temperature graph looks reasonable - it is a typical trace for a day when the cloud sometimes covers the sun. You stand to gain more accuracy by aspirating your temperature screen - by setting up a fan that will keep an airflow blowing across the sensors and not allowing air to stagnate and remain stationary near the sensors.
I have already tried using a solar driven fan that blows from the side onto the shield during july but with a very slight reduce in average temperature by 0,5c, i think the heatup within the radiation shield is manly caused by the surface of the shield that is mainly grey and not white which absorbs more latent heat, it doesn't matter how much air blows onto the shield as long as it heats up too much.

When this one is released and can be bought in a store it will change everything
https://www.purdue.edu/newsroom/release ... ally..html
Mapantz
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Weather Station: Davis Vantage Pro2
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Re: Davis vantage vue radiation shield not white enough? It looks light grey even at pictures on their website

Post by Mapantz »

I know i have to wrote: Tue 09 Aug 2022 10:03 am
I have already tried using a solar driven fan that blows from the side onto the shield during july but with a very slight reduce in average temperature by 0,5c, i think the heatup within the radiation shield is manly caused by the surface of the shield that is mainly grey and not white which absorbs more latent heat, it doesn't matter how much air blows onto the shield as long as it heats up too much.

When this one is released and can be bought in a store it will change everything
https://www.purdue.edu/newsroom/release ... ally..html
A fan blowing on to the shield does nothing. The fan needs to be inside of the shield..

In all honesty, I have never seen anyone complain about the colour of the radiation shield before?! Mine isn't grey either, it is white, and it doesn't get remotely warm if I put my hand on it during warm/hot weather.

I think you're being a bit paranoid about it to be fair..
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I know i have to
Posts: 7
Joined: Sat 16 Jul 2022 2:03 pm
Weather Station: Davis Vantage vue
Operating System: Windows 10 Home
Location: Örebro, Sweden

Re: Davis vantage vue radiation shield not white enough? It looks light grey even at pictures on their website

Post by I know i have to »

Mapantz wrote: Tue 09 Aug 2022 11:11 am
I know i have to wrote: Tue 09 Aug 2022 10:03 am
I have already tried using a solar driven fan that blows from the side onto the shield during july but with a very slight reduce in average temperature by 0,5c, i think the heatup within the radiation shield is manly caused by the surface of the shield that is mainly grey and not white which absorbs more latent heat, it doesn't matter how much air blows onto the shield as long as it heats up too much.

When this one is released and can be bought in a store it will change everything
https://www.purdue.edu/newsroom/release ... ally..html
A fan blowing on to the shield does nothing. The fan needs to be inside of the shield..

In all honesty, I have never seen anyone complain about the colour of the radiation shield before?! Mine isn't grey either, it is white, and it doesn't get remotely warm if I put my hand on it during warm/hot weather.

I think you're being a bit paranoid about it to be fair..
So what's the purpose for the radiation shield to have great ventilation if the effect of ventilation can't be reached if it's not blowing inside the shield? Anyways i painted the radiation shield a pure white colour without tones at 14:00 today and i can already see a big change on the fluctuations compared to yesterday with the same weather conditions.

http://www.bilddump.se/bilder/202208091 ... 22.173.png
RayProudfoot
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Re: Davis vantage vue radiation shield not white enough? It looks light grey even at pictures on their website

Post by RayProudfoot »

@I know I have to. A photo of your station might help. I wash my shields once or twice a year as I live in a suburban area. I would never paint my shields and I’m pretty certain Davis wouldn’t recommend it.

Where do you live?
Cheers,
Ray, Cheshire.

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I know i have to
Posts: 7
Joined: Sat 16 Jul 2022 2:03 pm
Weather Station: Davis Vantage vue
Operating System: Windows 10 Home
Location: Örebro, Sweden

Re: Davis vantage vue radiation shield not white enough? It looks light grey even at pictures on their website

Post by I know i have to »

RayProudfoot wrote: Tue 09 Aug 2022 6:26 pm @I know I have to. A photo of your station might help. I wash my shields once or twice a year as I live in a suburban area. I would never paint my shields and I’m pretty certain Davis wouldn’t recommend it.

Where do you live?
https://www.bildtagg.se/uploads/2022/22 ... 01t0yz.jpg
It looks like this, the tree pole that the station is mounted on is also painted white so extra heat radiation from this pole is not expected, even the original stainless steel pole from davis would heat up the surroundings more than mine does.

I live in a area of Urban Climate Zone Index 7 which means it's mostly surrounded by bigger empty grasslands with smaller houses in between, typical residential area light. What's interesting is that i usually record 0,2-0,7c colder temperatures during late evening and nighttime so obviously the exposure is enough since the aiport station is surrounded by even less objects.
RayProudfoot
Posts: 3372
Joined: Wed 06 May 2009 6:29 pm
Weather Station: Davis VP2 with Daytime FARS
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Location: Cheadle Hulme, Cheshire, England
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Re: Davis vantage vue radiation shield not white enough? It looks light grey even at pictures on their website

Post by RayProudfoot »

I know i have to wrote: Fri 12 Aug 2022 11:33 am It looks like this, the tree pole that the station is mounted on is also painted white so extra heat radiation from this pole is not expected, even the original stainless steel pole from davis would heat up the surroundings more than mine does.

I live in a area of Urban Climate Zone Index 7 which means it's mostly surrounded by bigger empty grasslands with smaller houses in between, typical residential area light. What's interesting is that i usually record 0,2-0,7c colder temperatures during late evening and nighttime so obviously the exposure is enough since the aiport station is surrounded by even less objects.
Well I still don’t know where you live. Country and State/ County will be fine. UCZI 7 means nothing to me. I don’t need your road and house number. :D

That setup looks very close to things that can generate heat. Is it positioned over grass? A wide angle photo would help.
Cheers,
Ray, Cheshire.

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I know i have to
Posts: 7
Joined: Sat 16 Jul 2022 2:03 pm
Weather Station: Davis Vantage vue
Operating System: Windows 10 Home
Location: Örebro, Sweden

Re: Davis vantage vue radiation shield not white enough? It looks light grey even at pictures on their website

Post by I know i have to »

RayProudfoot wrote: Fri 12 Aug 2022 11:48 am
I know i have to wrote: Fri 12 Aug 2022 11:33 am It looks like this, the tree pole that the station is mounted on is also painted white so extra heat radiation from this pole is not expected, even the original stainless steel pole from davis would heat up the surroundings more than mine does.

I live in a area of Urban Climate Zone Index 7 which means it's mostly surrounded by bigger empty grasslands with smaller houses in between, typical residential area light. What's interesting is that i usually record 0,2-0,7c colder temperatures during late evening and nighttime so obviously the exposure is enough since the aiport station is surrounded by even less objects.
Well I still don’t know where you live. Country and State/ County will be fine. UCZI 7 means nothing to me. I don’t need your road and house number. :D

That setup looks very close to things that can generate heat. Is it positioned over grass? A wide angle photo would help.
Sweden, Örebro. I must say that the picture does not really represent the siting location properly, it's at least 2,5m from both fences and the fence to the left never recives sunlight at all and the fence behind it for only 2-3 hours/daily and it's morning sun were talking about. I can accept heat radiation from fences to reach about 1-1,5m out but this far from it doesn't really make sense.

It's positioned 1,5m above a regularly mowed grass area which never dries out/gets yellowish so no summer-time effect there either.
Quote from Davis vantage sensor suite guidelines "Avoid installations near fences or sides of buildnings that recives a lot of sun during the day" Which isn't true in my case either, 2-3 hours is not a lot and wouldn't have that distinctly effect we are talking about here. And as you can see it's very open above the station basically under the sky which helps ventilation.
RayProudfoot
Posts: 3372
Joined: Wed 06 May 2009 6:29 pm
Weather Station: Davis VP2 with Daytime FARS
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Re: Davis vantage vue radiation shield not white enough? It looks light grey even at pictures on their website

Post by RayProudfoot »

I know i have to wrote: Fri 12 Aug 2022 1:11 pm
Sweden, Örebro. I must say that the picture does not really represent the siting location properly, it's at least 2,5m from both fences and the fence to the left never recives sunlight at all and the fence behind it for only 2-3 hours/daily and it's morning sun were talking about. I can accept heat radiation from fences to reach about 1-1,5m out but this far from it doesn't really make sense.

It's positioned 1,5m above a regularly mowed grass area which never dries out/gets yellowish so no summer-time effect there either.
Quote from Davis vantage sensor suite guidelines "Avoid installations near fences or sides of buildnings that recives a lot of sun during the day" Which isn't true in my case either, 2-3 hours is not a lot and wouldn't have that distinctly effect we are talking about here. And as you can see it's very open above the station basically under the sky which helps ventilation.
If you intend to post here put your location in your Profile settings please.

I think you’ll have to accept the situation. I can’t imagine the Vantage Vue shields are of a lesser quality than the VP2’s. I have no real solution for you, sorry.
Cheers,
Ray, Cheshire.

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