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  #51  
Old 06-19-2009, 11:57 AM
SoCalLandscapeMgmt SoCalLandscapeMgmt is offline
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Quote:
Originally Posted by Kiril View Post
@Dan

I'm curious how you were able to determine 0.001 accuracy when the unit only has a resolution of 0.01?
That was a typo on my part.... even the weather station on our Maxi-Com only has a resolution of .01. Too many zeros!
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  #52  
Old 06-19-2009, 12:03 PM
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FIMCO-MEISTER FIMCO-MEISTER is offline
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Quote:
Originally Posted by Kiril View Post
My take based on a quick review of the manual.

The additional features on this controller over the WMSL are definitely attractive and I would say a head and one shoulder above the WMSL. A few things I would point out.

1) I suspect historical averages are based on USDA plant hardiness zone and more likely than not should not be trusted.

2) It is most likely using a custom cooked version of the Penman-Monteith formula which should increase ET calculation accuracy over the WMSL.

3) Support for the landscape coefficient method is nothing short of impressive. Still not entirely there, but WAY better than WMSL. Perhaps support for manual entering KL would be a step in the right direction.

4) The interval (cyclic) option of 2-14 days is stoopid. Why they choose those values is beyond me.

Perhaps more comments to follow.


@Jim

The unit does not appear to operate any differently than the WMSL as it applies interval watering. It appears the controller just varies water times based on weather station and user input. This is no different than the WMSL, and in the same way, just as limited.

The only reasonable way that I see a controller of this class allowing for a true "skip day" feature is to have an option for manual setting allowable depletion values for each zone.

@Dan

I'm curious how you were able to determine 0.001 accuracy when the unit only has a resolution of 0.01?

-------------------

Despite my intense dislike for RB controller UI in just about all their controllers (other than this one) , all in all, if this controller had been on the market last year, I would not have recommended a single WMSL.
The only reasonable way that I see a controller of this class allowing for a true "skip day" feature is to have an option for manual setting allowable depletion values for each zone.


Nice thinking Kiril. Does any controller do this?

UI means user interface?
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  #53  
Old 06-19-2009, 12:07 PM
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Wet_Boots Wet_Boots is online now
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Here's a thought - I often program a controller with an eye towards when household water use begins. If I want the watering to cease by 6AM, and I have set a window from 1AM to 6AM, will the controller move up the starting time of the watering cycle? Maybe a 2-hour cycle will become 4 hours at the height of summer.
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  #54  
Old 06-19-2009, 12:08 PM
Kiril Kiril is offline
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Quote:
Originally Posted by Tony Clifton View Post
In my opinion how can you have an ET controller without an anemometer???
Completely agree here. The weather station should at a minimum support a optional anemometer and the controller zone location with respect to compass direction.
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  #55  
Old 06-19-2009, 12:17 PM
Kiril Kiril is offline
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Quote:
Originally Posted by JimLewis View Post
The thing is they can get E.T. dialed in pretty dang close just by using historical wind speeds (per month) for your zip code. Take a look at the SWAT testing they did on this unit. Most zones were off from what actual E.T. was by around 1.5%. The very highest zone in the test was off by a little over 6%. That's better than almost every E.T. product out there - and WAY WAY WAY closer than what we've all been getting with traditional time-based controllers. So when you're getting that close with your unit, is it really worth spending an extra $450.00 just to get a tad closer????
I know I have said this before, but I will say it again. Don't put a lot of faith in the SWAT testing. Beyond that, given most landscape plants do not even have a determined Kc, or ETc, stating ET percentage variance is more than a little misleading.

Quote:
Originally Posted by JimLewis View Post
I think the consensus was that they can get pretty dang close just using historical wind speeds rather than having to spend the money on something to measure exact current wind speeds.
I seriously doubt wind speeds used by this controller consider the influence of site vegetation and buildings on wind speed and direction, both of which can have an enormous effect on AE. A well chosen location for the weather station and an anemometer would go a long way towards maximizing AE.
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  #56  
Old 06-19-2009, 12:20 PM
Kiril Kiril is offline
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Quote:
Originally Posted by JimLewis View Post
At least with Rain Bird, they already made up their mind. They decided they wanted the full equation and that wind speed was an important part of that equation.
They are still not supporting the full Penman-Monteith formula. Assumptions and approximations are being made.
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  #57  
Old 06-19-2009, 12:24 PM
Kiril Kiril is offline
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Quote:
Originally Posted by FIMCO-MEISTER View Post
The only reasonable way that I see a controller of this class allowing for a true "skip day" feature is to have an option for manual setting allowable depletion values for each zone.


Does any controller do this?
Honestly, I don't know. I will assume any controller that supports soil sensing does.

Quote:
Originally Posted by FIMCO-MEISTER View Post
UI means user interface?
yes
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  #58  
Old 06-19-2009, 12:41 PM
SoCalLandscapeMgmt SoCalLandscapeMgmt is offline
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We can debate whether or not the supplied weather pod is sufficient or not all day long but like I said before.... the ET values that this controller calculates have been within .01" of a $10K full blown Campbell Scientific weather station that I have at my house. I don't know about you guys but it seems to me that as long as the thing is that accurate the point of whether or not it has an anemometer is irrevelant. You get out into the real world of landscape and how things usually get installed and .01" of ET doesn't make a bit of difference when you get right down to it. I know that on some of the other field tests the units were checked against Maxi-Com weather stations and they had the same results as I observed.
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  #59  
Old 06-19-2009, 12:48 PM
Kiril Kiril is offline
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Dan, before I would go to the length of saying it is 0.01 accurate compared to a full blown weather station, I think at least of full years worth of data points at a minimum interval of 1 hour would be necessary.

Second, there is more to wind speed/direction as it applies to maximizing irrigation efficiency than simply a single variable in an ET calculation (see post #55).
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  #60  
Old 06-19-2009, 12:52 PM
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FIMCO-MEISTER FIMCO-MEISTER is offline
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Keeping it affordable and usable is key as well. Remember Kiril your avg installer isn't going to have the depth of knowledge you do. Get it too complicated and expensive and it ain't gonna fly. There are controllers that do what you want on the market now.
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