Rotary nozzles...really water saving?


#1

Hello everyone, as you all have heard, rotary nozzles claim to save water. I get the claims of less run off, better soaking, more efficiency, yadi yada.

However, because it doubles the watering duration (as automatically adjusted by the flex schedule) compared to conventional nozzles, I am not convinced that rotary nozzles actually save water that much when speaking in terms of absolute amount of gallons used.

What are y’all’s thoughts ?

Thanks

Love the forum discussions.


#2

Hmm…great question, definitely above my pay grade :wink:, hopefully someone else will know the answer, I bet @emil has an opinion on this.

:cheers:


#3

Or @plainsane :smile:


#4

They will save some water in a windy environment. I want to eventual switch over to them because the blades of grass have less moisture on them at the end of a cycle, but honestly rachio pretty much rendered those things obsolete with their smart cycle feature.


#5

Agreed.


#6

They do appear to help on windy days. Less water mist blowing over the driveway, so there is some savings in certain conditions.

The slower application rate helps with soaking and the ability to have larger zones due to lower GPM.

I switched from sprays because the zones were designed too large and there wasn’t enough pressure to evenly cover the area. Rotary nozzles fixed it without splitting a zone and all the digging to add a valve.

But your right, they flow 1/2 the rate and you run them twice as long, so same water amount is going through the system. There is no magic, unless you can cut back because of better application.

In my particular case, I find rotary is applying it better, so I believe I am seeing some savings. I can water the same area with less gallons because the coverage is more even.

I do track my gallons/gaons per minute at the meter pretty regularly.

All cases are not equal of course.


#7

@Rightbundle, great question. @plainsane and @brkaus couldn’t have said it better.

Rotary nozzles are all about water delivery. This video goes into the details and sounds more exciting than me :wink:

This is another good use case for installing rotary nozzles. Out of curiousity, would you mind sharing with us (ballpark) the cost to convert your system @brkaus?

Thanks @plainsane :blush:


#8

It was about $6 per head, all I had to do was switch nozzles. But sprays are about $0.50.

I couldn’t convert one odd shaped zone due to lack of pattern choices.

I can never leave well enough alone, so I did replace a set of pop-up bodies with 5" bodies (from 3") because the grass tends to grow fast there and cover the head. That cost another $6 per head and required digging.

Negative for rotators is watering finishes much later now. May combine a few similar zones (and steal a valve to add a pot drip zone).

Positive is that look cool.

Other positive is all sizes deliver same precipitation rate.

Just never mix-n-match nozzles types on a single zone.


#9

Precisely :slight_smile:

IMO … the way to get huge savings is to remove turf & replace with native plants that are drip irrigated.


#10

Curse your blasphemous mouth :wink:


#11

LOL :slight_smile: … Just thinking outside the box.


#12

@brkaus, thanks for sharing. It’s a pretty easy retrofit for DIY’ers.

Not so easy, but hopefully worth the effort. Do you have 3" spray head bodies throughout your lawn otherwise?

Just curious, what is the precip rate for your nozzles?

Touche, they can be very hypnotising :wink:

Matched precip is an awesome benefit to these heads that it often overlooked.


#13

I put some in last summer for 2 zones but they just aren’t worth the hassle. Watering is like 2.5x in reality for the converted zones. I now run the risk of all zones not completing in our restriction window . They take forever to blowout.

So just use the Rachio smart features with fixed sprayers. It works well.


#14

I’m getting 0.5 in/hr based on GPM and area. Purchased a set of catch cups but haven’t had a chance to use.

They did some some critical problems for me, so I’m happy with them.

I do still have some of the smaller pop-up bodies in the yard, wish they were all 5", but I don’t have 5" of soil so it takes a lot of chipping at rock that I’m not willing to do.


#15

@Hooper, yes they do have a lower application rate which will result in a lower precipitation rate and longer watering durations.

@brkaus, maybe this weekend? :wink:

I don’t blame you. Seems like a good excuse for the if it’s not broken, don’t fix it logic.


#16

I’m in the process of changing over to MP Rotators now. I have 45 spray heads and 11 rotors across 5 zones. Obviously starting with the spray head zones first b/c it’s the easiest to switch out. Just twist off the spray head, twist on the MP rotator, and adjust to your lawn (no digging).

I did a very unscientific comparison with catch cups before & after swapping out. Here’s the graph for 2 zones i converted. Blue is the old spray heads and red is the new MP rotators after a 10 minute run:

2 takeaways that I can see…

  1. MP rotators do use less water, as advertised, so you will have to run them longer.

  2. MP rotators have a more even application (still not perfect) than my old spray heads.

YMMV but I’m pleased so far. Plus they look cool :grin:

edit: duplicate img


#17

This is some serious irrigation geekness. We are not worthy! I’m sure @emil will be jealous.

Thanks for sharing.

:cheers:


#18

@johnny2678 Very cool!


#19

I won’t lie, I’m pretty jealous. These just might end up in the 2017 Rachio Calendar :wink:


#20

I’ll buy one, can ya sneak one in for me http://resources1.news.com.au/images/2010/09/28/1225930/571417-gold-coast-bikini-race.jpg