Topic: How high above a fence?

[Weatherwx85]

Hi,
I have my station fitted on an 8ft high fence on a J bracket, the wind vane is about 12inches above the top of the fence. I recently removed some plants from the fence and have since noticed my wind direction is now very erratic (was ok before). I presume this is becuse the plants have been removed it is no longer dampening the wind so it is more turbulent, what is the minimum clearance I should have between the top of the fence and the wind vane?

Example wind from today:

Thanks

[lightmaster]

Mine's 20ft high in a field with no obstacles higher than 5ft off the ground for >200ft, and it's still erratic today. Some days it fairly consistent though... Make of that what you will.

[Weatherwx85]

sample before plants removed

[Weatherwx85]

Mine's 20ft high in a field with no obstacles higher than 5ft off the ground for >200ft, and it's still erratic today. Some days it fairly consistent though... Make of that what you will.

Interesting, I am in the UK, comparing mine to others I do seem to be the odd one out, it could be a coincidence though I guess?

[galfert]

You didn't say what station model you have. The newer WH2900/WS-2902A sensor array has better dampening than to older WH24 type.

[Weatherwx85]

You didn't say what station model you have. The newer WH2900/WS-2902A sensor array has better dampening than to older WH24 type.

Hi,
It appears to be a UK version of the WS-2902A branded as a Ventus W830

[Bashy]

I have a Davis and i have seen eratic too at times, i am @ 10m height in a village, i think it depends on the speeds but i will say that being only 1 foot above the fence is not great, you will get a lot more erratic behaviour than you would say 8ft above it.

1st image mine from yesterday, gusts upwards of 30mph
2nd image was much lower wind speeds

[Weatherwx85]

Hi,
I measured the last pole and it was actually less than 6", I have purchased a new pole and bracket, it is now 2 feet about the fence so 10 feet total, I have attached a picture. Hopefully this helps, if nothing else I should get better wind speeds

[galfert]

That looks great. Nice job.

Question though. How far is it from the nearest building? And how tall is the building?

Ideally it should be separated from the building at 4 times the difference in height.
For example if the building is 18 feet high, then the difference in height is 8 feet. So the sensor array should be placed at 4 times 8 which is 32 feet away.

If you are limited by distance then you work backwards to figure out how high you should place the sensor array.
For example if the building is 18 feet tall and you are limited in distance at your desired location to say 24 feet, then the difference in hight should be 6 feet, which means the poll for the sensor array should then be 12 feet high.

[Weatherwx85]

Hi,
About 30 feet, building is a standard two storey house, so height is a compromise but going too much higher may annoy the neighbours it does seem better higher though so will see how it goes I have a little more height to play with if needed.

[galfert]

Hi,
About 30 feet, building is a standard two storey house, so height is a compromise but going too much higher may annoy the neighbours it does seem better higher though so will see how it goes I have a little more height to play with if needed.

Then your ideal pole height should be around 15 feet.

Neighbors will get used to it. Give them access to your weather data online and they'll be happy you are providing a great service.

For now keep it as is. Later on when everyone is used to seeing it there, raise it.    They won't know the difference and they will think it was always like that.

[Weatherwx85]

Hi,
About 30 feet, building is a standard two storey house, so height is a compromise but going too much higher may annoy the neighbours it does seem better higher though so will see how it goes I have a little more height to play with if needed.

Then your ideal pole height should be around 15 feet.

Neighbors will get used to it. Give them access to your weather data online and they'll be happy your are providing a great service.

For now keep it as is. Later on when everyone is used to seeing it there, raise it.    They won't know the difference and they will think it was always like that.

1 foot a month, will be done in 5 months

[Weatherwx85]

Much better today 

[Notsorusty]

I have a question regarding the better location for these all-in-one-units. Obviously you have to compromise because all of the sensors are in the same unit and you can be limited by the size and location of your property. I installed my WS-2902A about a year ago and am very pleased with its performance, other than the recent WU issues. It is placed on a pole attached to the peak of the garage about 5 feet above the roof (about 17 feet above the ground). The front of the garage is about 20 feet northeast of the 2-story house. There is a rather tall pine tree that is about 75 feet to the southeast (possibly 50 feet tall). Another tall pine tree located behind the garage in the neighbor's yard. We have a small tree-lined creek across the back of the lot (east side of the property). Location wise I think that this is the best spot on the property. I know that 33 feet is the optimal height for the anemometer but that seems too extreme for rain and temperature measurements not to mention maintenance. I could go with a higher pole but don't know if the end result would be worth it. Any thoughts?

[Weatherwx85]

I would say if you are happy with the results and it’s easily accessible leave it where it is. No point in moving it for the sake of doing so and then making it more awkward to service.

[galfert]

I have a question regarding the better location for these all-in-one-units. Obviously you have to compromise because all of the sensors are in the same unit and you can be limited by the size and location of your property. I installed my WS-2902A about a year ago and am very pleased with its performance, other than the recent WU issues. It is placed on a pole attached to the peak of the garage about 5 feet above the roof (about 17 feet above the ground). The front of the garage is about 20 feet northeast of the 2-story house. There is a rather tall pine tree that is about 75 feet to the southeast (possibly 50 feet tall). Another tall pine tree located behind the garage in the neighbor's yard. We have a small tree-lined creek across the back of the lot (east side of the property). Location wise I think that this is the best spot on the property. I know that 33 feet is the optimal height for the anemometer but that seems too extreme for rain and temperature measurements not to mention maintenance. I could go with a higher pole but don't know if the end result would be worth it. Any thoughts?

With an all in one the sweet spot in height is 13 to maybe 16 feet. It's all about the compromise of anemometer height and temperature/rain height. Shouldn't go higher because then you affect temperature and rain. But that said it's also about what is most important to you. As some find that wind is more important and some value rain as more important. There is no perfect answer as it's up to you what is most important. If there is no most important datum to you then stick to the 13 to 16 feet. But 17 feet is close enough. Because of the two story house at 20 feet away I'd say your station height is adequate. Sounds like it's as good as it can be.

[Notsorusty]

Thanks for the confirmation. I don't remember seeing the 13 to 16 foot recommendation when I was researching the placement for weather stations. Just far away from everything, 5 feet above roofs and way up in the sky. My readings are all very close to other nearby stations, including O'Hare Airport which is about 10 miles away.

[CW2274]

I don't remember seeing the 13 to 16 foot recommendation when I was researching the placement for weather stations.

Because for an "all-in-one" there is none. As 'galfert' states, that's the problem with them, you have to compromise with what's more/most important to you. His recommendation is as good as any. Up to you.