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Irrigation audit results

Discussion in 'Irrigation' started by DanaMac, Aug 27, 2012.

  1. DanaMac

    DanaMac LawnSite Fanatic
    Posts: 13,156

    So, since it is a little slow for us, I took my guys to Ewing for a day, and we did some auditing. When they built the building, and did the landscaping, the manager had some say in the irrigation design. There is one section that is 30'x30', and it has 3 zones that water it, for this exact purpose of auditing.
    Zone #1 has 4 rotors, all in the corners.
    Zone #2 has spray heads spaced at 10' apart, standard RB nozzles.
    Zone #3 has spray heads spaced at 15' apart, standard RB nozzles.
    They water this 30x30 section, and nothing else.

    I didn't worry about the rotors, as I wanted to compare some spray nozzles and MPs. We did 5 different audits. Once I enter the info into a spreadsheet, I'll post those as well. We used 48 catchments, and kept them all in the same places for all 5 audits. We calculated the audit two different ways - one was with all 48 cans, and a secondary audit with 40 cans, eliminating the 6 along the front edge of the direction of the wind, and 2 more along the next row. It wasn't bad, but it was maybe 5-8 mph at times. The measurements were fairly weak along that front row due to the wind.

    Grass was a little long, and affected the 10' nozzles due to a lower angle. A few heads were a little crooked, but not too bad

    Audit #1 - 10' spacing - standard RB nozzles - 35 psi at the heads - 5 minute run time
    Initial audit = 35.5% DU
    1.84" per square foot per hour (psfph)
    This one stayed at about 35.5% even removing the 8 heads

    Audit #2 - 10' spacing - Toro Precision nozzles - 42 psi - 5 minute run time
    Initial audit = 20% DU
    1.16" psfph
    Secondary audit = 26% DU
    1.25" psfph

    Audit #3 - 15' spacing - standard RB nozzles - 28 psi - 5 minutes run time
    48% DU
    1.59 psfph
    Secondary = 61.7% DU
    1.75" psfph

    Audit #4 - 15' spacing - Toro Precision nozzles - 32 psi - 5 minutes run time
    Initial audit = 49% DU
    0.97" psfph
    Secondary = 69% DU
    1.09" psfph

    Audit #4 - 15' spacing - Hunter MP 2000 - 40 psi - 10 minutes run time
    Initial audit = 69% DU
    0.61" psfph
    Secondary audit = 72.6% DU
    0.65" psfph
    **this is a little screwy because you wouldn't normally put MP 2000s 15' apart - but it's what we used**

    I know the MP spacing was not right for the 2000s, but they were overwhelmingly more consistent. We can read it in the spec sheets all we want, but until we see them work in the field, it doesn't mean much. The consistency of the catchments was mind blowing, compared to the standard nozzles. I should have tried the 1000s, or even the 3000s with the half circles plugged off.

    I did not do the calculations myself for all the audits, nor have I checked the math for all 5 audits. The three of us worked different ones. So when I enter into my spreadsheet, the numbers may be off somewhat. Just thought I would share our findings with you all.
     
  2. 1idejim

    1idejim LawnSite Fanatic
    Posts: 8,810

    That's cool. Maybe Audit & Ale will become a yearly doings!
    Posted via Mobile Device
     
  3. DanaMac

    DanaMac LawnSite Fanatic
    Posts: 13,156

    I just really like how they have this one section set up, so we can do multiple audits with mutiple products, all for the exact same 30x30 section. We could have spent all day there auditing the 5004 rotors and then changing to LA nozzles, we could have tried all three of the MPs, we could have done the RB and Toro rotators to compare as well.

    TomTom and I were there this spring for an audit class using the same area. But it was very windy that day, and numbers were all over the place. I asked at that time if I could come back with my employees and spend time here with multiple products. When I was there last week doing it, they mentioned I was the only one that has ever asked to do this on my own time, without their class. It felt good that we are trying to be better than the average company out there, and take the initiative to learn these things. Poor TomTom couldn't make it though, as he was in Alaska :( Must be rough.
     
  4. Duekster

    Duekster LawnSite Fanatic
    from DFW, TX
    Posts: 7,961

    I bet the MP's would do even better with proper spacing. Interesting note on the pressure of the Toro... I see the spacing is different too.

    I would like to see a 30 PSI vs 40 PSI comparison between the Toro and the MP.... both having proper spacing.

    I have spread sheet "somewhere" and the increased DU saves a ton of water.

    I still believe the MP's are more tolerant over a wider range of pressure. Nonetheless I like the at head pressure regulation.
     
  5. DanaMac

    DanaMac LawnSite Fanatic
    Posts: 13,156

    The last few years, we changed to only buying the undercut series from RB, for standard nozzles. This year, we haven't bought many standard nozzles, but we have bought a ton of Precisions and MPs. With the MPs, the customers also get a $4 rebate from Colorado Springs Utilities - minimum of 5, and maximum of 40. We've done quite a few renovation jobs changing over to MPs.
     
  6. Duekster

    Duekster LawnSite Fanatic
    from DFW, TX
    Posts: 7,961

    No rebates here but the savings is good. The lawns look happy, less brown spots and the water bill is lower. The MP is a great R&R upgrade.

    The Toro's I installed seemed ok but I doubt they will deal with the wind as well.
     
  7. muddywater

    muddywater LawnSite Bronze Member
    Posts: 1,813

    That is neat. Precipitation rate is close to spec on mps.

    How does that rebate work? $4 rebate per head?
     
  8. DanaMac

    DanaMac LawnSite Fanatic
    Posts: 13,156

    Yes, $4 per MP rotator. http://www.csu.org/residential/rebates/Pages/irrigation.aspx

    They cap the rebates at $200 per household. But there are rebates for rain sensors, check valved heads, and weather based controllers.
     
  9. muddywater

    muddywater LawnSite Bronze Member
    Posts: 1,813

  10. grassman177

    grassman177 LawnSite Fanatic
    Posts: 9,795

    Very cool,i doubt my ewing has any of that got audit purposes..would be cool.
    Posted via Mobile Device
     

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