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"Smart" ET-based
controllers... are they right for your yard?
In California,
Assembly Bill 1881 passed in 2007.
It implements
various water conservation guidelines, and features a
requirement that all sprinkler controllers sold in California
by 2012 include "irrigation scheduling that is
sensitive to climate"
We think this is
a great idea! Sprinkler manufacturers have already been working in
this direction for a while. Newer ET-based controllers promise the
best water-conserving irrigation technology to date.
So, what
exactly is "ET" ?
ET is short for
evapotranspiration, which is the measurable amount
of water lost from plants due to a combination of factors
such as wind, temperature, humidity, and even hours of daylight.
ET data is collected
from weather stations to adjust scheduling to actual local weather
conditions.
ET data has been used
for years to schedule watering in parks, golf courses and
agriculture, so that irrigation is based on replacing
actual water lost, rather than guesswork.
As these new
controllers have become more competitively priced for
residential applications we are offering them to our customers,
both in new installations and as retrofits to existing systems.
There are two kinds of
ET- based controllers available.
One kind relies on a network of weather
stations and ET data collected miles away
and communicates with your controller via satellite, a phone
line or the Internet, and requires an ongoing
subscription.
Updated - April
2007
Of these we have recently checked
out the WeatherTRAK by Hydropoint and WeatherTRAK
enabled controllers from Irritrol and
Toro, took their online training course, and got
certified to install them.
These controllers get regular
updates via satellite transmission. Subscription fees start at $48
per year.
Photo and
logo courtesy of Irritrol and Weathertrak
The other kind uses a
single on-site weather station.
Updated - November 2006
For those of you who already have Hunter
brand sprinkler controllers, please click here for an ET-based retrofit called the ET
System.
Otherwise,
please continue reading.
We've done the research and experimented with the
Weathermatic Smartline
controller. We installed one on a 22 unit townhouse complex in
Campbell, and we'll be monitoring it regularly over the next growing
season to see how it does.
It has a nice backlit display, and other well
designed features like a built in
ammeter for electronic diagnostics, and built
in valve locator for finding lost valves under ground
cover or shrubs.
There's a seasonal adjustment
feature that allows you to schedule watering by
setting monthly percentages (from your peak watering of 100
percent for July in our climate) calendar.
And these are just the features of the conventional side
of the controller.
In addition, with the addition of the optional
weather monitor, you can turn it into an ET-based
controller and switch to Auto Adjust
mode.
The Smartline is available in 2 models that
expand from either 4 to 16 zones or 12 to 48 zones (from a
typical residential landscape to a large park) via add-on modules.
Weathermatic expects to sell a lot of
these controllers and we can see why.
Photo and logo
courtesy of Weathermatic
For sprinkler controller
troubleshooting, repairs or replacements, and questions
about "Smart" sprinkler controllers, call
us.
408.369.1391 | 
