Topic: dramatically improve the davis 7714 solar shield

[G.Brown]

I'm still unsure if the bottom plate should also be painted black?

[ivano]

I'm still unsure if the bottom plate should also be painted black?

hello, have you seen the daily charts that I publish? open the link I posted, you will realize that the last plate must be painted black, https://u.pcloud.link/publink/show?code=kZ1LgbVZBf5t5G5lxqzfAfQl1uPiBX1PGNKk

[G.Brown]

the results dont compare with and without the bottom plate painted black - to clarify mean the bottom (outside) of the bottom plate - others ie Galfert has said the bottom of the bottom plate should be white. The bracket (on the bottom) of the spiral type enclosure is also white....still not resolved?

[ivano]

the results dont compare with and without the bottom plate painted black - to clarify mean the bottom (outside) of the bottom plate - others ie Galfert has said the bottom of the bottom plate should be white. The bracket (on the bottom) of the spiral type enclosure is also white....still not resolved?

guys but why does the bottom of the last plate have to be white? with what criterion is this said? has anyone tried the white dish then the black dish? here I did it, and the result was to make it black there will be a reason, it is not a whim

[mcrossley]

My guess would be it depends on what is below the shield. If it is a surface that radiates any degree of heat you want it white, over say grass it may be better black. Proximity probably comes into too. The "safest" general option is probably white?

[ivano]

My guess would be it depends on what is below the shield. If it is a surface that radiates any degree of heat you want it white, over say grass it may be better black. Proximity probably comes into too. The "safest" general option is probably white?

ciao, la tua ipotesi ha fatto centro, è proprio da questo che dipende la scelta effettuata nel colorare di nero l'ultimo piatto

[ivano]

The black davis 7714 is still being tested, it has now been two and a half months of testing, in all weather conditions it has proved its effectiveness
 [ You are not allowed to view attachments ]  

[ivano]

  [ You are not allowed to view attachments ]  Good evening everyone, this is the summary of the Davis 7714 test with the inside of the plates colored black, the test was carried out between the last week of August and the whole month of November, the screen which was taken as a reference for the test it is the third generation Meteoshield new pro by Barani,. [ You are not allowed to view attachments ]  the sensors used are the wh32/312 EP probe with sensirion SHT35, the sensors were aligned before the start of the test, in the post above you will find all the photos from the coloring of the dishes, and the comparison station, the test has ascertained that in this configuration the Davis 7714 has significantly improved in its performance, in all weather conditions, obviously these results are valid in my weather station, it would be interesting to have someone repeat the same test, anyone who wants to try I'll be happy to share my experience in all respects 

[vinceskahan]

Some words mentioning your conclusions might be helpful.

[i know i have to]

I tried this yesterday painting all of the inside darkest matt black but i didn't get the wow-effect yet on the temperature, the temperatures still increases "too much" of what is expected when the sun comes out. For being the 2nd worlds best passive radiation shield there must be something else you can improve it with.

[G.Brown]

 [ You are not allowed to view attachments ]  
you can see the bottom mounting bracket is white and I assume the bottom plate is also white - in contradiction to what has already been discussed?

[ivano]

hello, from what do you deduce that it still detects high temperature values? do you have it in comparison with? it is by no means the second best performing screen in the world, in normal conditions (white) it takes those 06/07 tenths from a meteoschield pro or a metspec, or a Comet, making it black inside, should reduce this distance, maybe if you have some photos of your work... to better understand

[i know i have to]

hello, from what do you deduce that it still detects high temperature values? do you have it in comparison with? it is by no means the second best performing screen in the world, in normal conditions (white) it takes those 06/07 tenths from a meteoschield pro or a metspec, or a Comet, making it black inside, should reduce this distance, maybe if you have some photos of your work... to better understand

Well the temperature increase always comes very shortly after the sun starts shining on the shield, especially notable when it's been cloudy for a long period before.As you can see on this picture the temperature increased from -0,4 to 1,8 within just a hour, 3 times faster than nearby stations including airport station.

For the whole march i have now compared my data to the airport and on average my stations reads -0,5c colder on cloudy days and 1,3c warmer on sunny days, i expect the reason for it to be colder on cloudy days comes from the compact structure of the davis 7714 which protects too much, while on sunny days the compactness makes it read higher values with too many inner parts warming up

There's nothing to question wether Davis 7714 is one of the best passive radiation shields out there, on this particular experiment it even had a t-max value 5c colder than a TFA radiation shield, even if that one is too cheap to almost count as a shield.

[JCA433]

hello, from what do you deduce that it still detects high temperature values? do you have it in comparison with? it is by no means the second best performing screen in the world, in normal conditions (white) it takes those 06/07 tenths from a meteoschield pro or a metspec, or a Comet, making it black inside, should reduce this distance, maybe if you have some photos of your work... to better understand

Well the temperature increase always comes very shortly after the sun starts shining on the shield, especially notable when it's been cloudy for a long period before.As you can see on this picture the temperature increased from -0,4 to 1,8 within just a hour, 3 times faster than nearby stations including airport station.

For the whole march i have now compared my data to the airport and on average my stations reads -0,5c colder on cloudy days and 1,3c warmer on sunny days, i expect the reason for it to be colder on cloudy days comes from the compact structure of the davis 7714 which protects too much, while on sunny days the compactness makes it read higher values with too many inner parts warming up

There's nothing to question wether Davis 7714 is one of the best passive radiation shields out there, on this particular experiment it even had a t-max value 5c colder than a TFA radiation shield, even if that one is too cheap to almost count as a shield.

You may have a problem with reflected sunlight  inside the shield.   My location is near tropics with a high sun angle even this time of year so I rarely if ever have this problems with the Davis 7714 shield.

[ivano]

Hello everyone, if you have done the interior painting well and you have placed the sensor from below, you will have these performances, [ You are not allowed to view attachments ]   [ You are not allowed to view attachments ]  
and rest assured that this is the only way to test the performance of one screen against another, not with those nearby etc etc etc .

[i know i have to]

Hello everyone, if you have done the interior painting well and you have placed the sensor from below, you will have these performances, [ You are not allowed to view attachments ]   [ You are not allowed to view attachments ]  
and rest assured that this is the only way to test the performance of one screen against another, not with those nearby etc etc etc .

Why are you ignoring all of the text i just wrote to you, are you f**king retarded or something? Such a typical narcisstic move of you. I just f**king wasted 2 hours of my life painting the inside of the shield black because of your shitty advice without any results, i could have installed a solar driven fan inside of it instead.

[ivano]

Hello everyone, if you have done the interior painting well and you have placed the sensor from below, you will have these performances, [ You are not allowed to view attachments ]   [ You are not allowed to view attachments ]  
and rest assured that this is the only way to test the performance of one screen against another, not with those nearby etc etc etc .

Why are you ignoring all of the text i just wrote to you, are you f**king retarded or something? Such a typical narcisstic move of you. I just f**king wasted 2 hours of my life painting the inside of the shield black because of your shitty advice without any results, i could have installed a solar driven fan inside of it instead.

Congratulations for your lexicon, really .... (reported anyway).. unfortunately I have seen your messages, I have seen the photo, a fraud of stations set up without any logic, just to put something on the post, one at the bottom, one north , one attached to the pole , one up , are you comparing davis performance against what ? with who? I saw that you have a ventilated vp2, put the davis 7714 black screen at the same height, the same SOUTH orientation, it is clear if the wind is absent or very weak, the vp2 pro wins easily, but in normal conditions with a little wind 10 km/h the black davis is superior, if you have photos of when you colored the davis black and the position of the sensor inside, let me see them.

[mauro63]

Hello everyone, if you have done the interior painting well and you have placed the sensor from below, you will have these performances, [ You are not allowed to view attachments ]   [ You are not allowed to view attachments ]  
and rest assured that this is the only way to test the performance of one screen against another, not with those nearby etc etc etc .

Why are you ignoring all of the text i just wrote to you, are you f**king retarded or something? Such a typical narcisstic move of you. I just f**king wasted 2 hours of my life painting the inside of the shield black because of your shitty advice without any results, i could have installed a solar driven fan inside of it instead.

In our Italian forum, a message like yours would have immediately resulted in a definitive ban by the Staff, but evidently everything is allowed here, even calling a user mentally retarded.

My compliments, not so much to the user, obviously suffering from serious problems, but to the management of the forum

M.

[JCA433]

My Davis 7714 performance with insides painted black are similar to IVANO.  I can confirm it works!

[saratogaWX]

Why are you ignoring all of the text i just wrote to you, are you f**king retarded or something? Such a typical narcisstic move of you. I just f**king wasted 2 hours of my life painting the inside of the shield black because of your shitty advice without any results, i could have installed a solar driven fan inside of it instead.

Your reply is abusive.  Refrain from posting ad hominem attacks or you will be removed from the forum.

BTW: I try to leave examples of bad behavior up to demonstrate what NOT to post.  I generally try to give only one warning, and eject the person on the second instance.  Hopefully, there won't be a second instance by them.

[Buick]

I recently painted the undersides of all of the plates of my 7714 except the bottom one matte black and it appears that the modification was an improvement with regard to its previous performance compared to my 24hr FARS. I won’t know with certainty to what degree, if any, there has been an improvement but my initial impression is positive which is really saying something because the 7714 always held its own against the FARS fairly well. I used low VOC, water-based spray paint and would recommend Montana Colors Polyurethane Water Based Matte Carbon Black https://www.montanacolors.com/en/productos/graffiti-water-based-300-aerosol-paint/, Pintyplus Evolution Acrylic Water Based Matte Jet Black https://www.pintyplus.com/usa/products/pintyplus-evolution-acrylic-water-based-spray-paint/ or Liquitex Acrylic Water Based Matte Carbon Black https://www.liquitex.com/us/product/liquitex-professional-spray-paint/?attribute_pa_ecommerce_size=12oz-400ml&attribute_pa_liquitex_colour_name=carbon-black.

[G.Brown]

I used some 30+ year old black board paint that was lying around - no problems.

[JCA433]

Some unexpected minor issues with the Davis 7714 shield painted black inside revealed after extensive testing in August, September, and October this year.


1.  There is a slight radiational cooling effect overnight relative to fan aspirated shield.  The low temperature is often 0.4F to 0.8F lower.  This a small error and not that significant.

2.  It sometimes misses the high temperature in some weather conditions especially windy mostly cloudy to party cloudy conditions due to lag.  This is also not a big error only about 0.2 to 0.5F.  It performs better in windy sunny fair conditions with average wind speeds 3 Knots or higher. 
 
3.  During intense sunlight and no wind conditions it will read temperatures as much as 2 to 2.5F above the FARS.  These conditions are most likely in the morning period between 9AM and 12PM.  The Davis 7714 shield with insides painted black is a very good passive shield and does not need much wind just a little, but it does require some wind.  It is very rarely more than 2F above and only observed a few times and only in very intense sunlight dead calm no wind conditions.  If there is just a little wind it will often be within 1F of the FARS

These observations were made with the SHT31 temperature and humidity sensor inside the Davis 7714 shield.

[JCA433]

For February, March, and April this year the Davis 7714 with insides black average maximum temperature was about 0.3F below the FARS and August, September, and so far October 0.3 to 0.4F above the FARS.  The average temperatures are nearly the same.

[CW7491]

Some unexpected minor issues with the Davis 7714 shield painted black inside revealed after extensive testing in August, September, and October this year.


1.  There is a slight radiational cooling effect overnight relative to fan aspirated shield.  The low temperature is often 0.4F to 0.8F lower.  This a small error and not that significant.

2.  It sometimes misses the high temperature in some weather conditions especially windy mostly cloudy to party cloudy conditions due to lag.  This is also not a big error only about 0.2 to 0.5F.  It performs better in windy sunny fair conditions with average wind speeds 3 Knots or higher. 
 
3.  During intense sunlight and no wind conditions it will read temperatures as much as 2 to 2.5F above the FARS.  These conditions are most likely in the morning period between 9AM and 12PM.  The Davis 7714 shield with insides painted black is a very good passive shield and does not need much wind just a little, but it does require some wind.  It is very rarely more than 2F above and only observed a few times and only in very intense sunlight dead calm no wind conditions.  If there is just a little wind it will often be within 1F of the FARS

These observations were made with the SHT31 temperature and humidity sensor inside the Davis 7714 shield.

I’ve witnessed the exact same results over a period of 2 years. The 7714 with black painted interior is an amazingly good, inexpensive passive shield. It’s weaknesses are lag, strong low sun angle and light wind, and clear calm nights with strong radiational cooling. I’ve had better results with it than the Barani Meteoshield Pro. My experience is spot on with your experience with strong, low sun angle and light wind. Once the sun is overhead the shield performs extremely well. At night with strong outgoing radiation, I observed it reading about 1°F low on average.