Robert Pogson

I love web applications. They allow me to stay in my nice, comfortable, tweaked web browser and do amazing things. Today, I visited http://orbit.homedepot.com/planner and planned an underground sprinkler system for my lot. It worked pretty well. The application combined my specifications of the lot, landscaping, water supply and buildings with the company’s database of components to produce a viable plan for irrigation for $7700 in parts.

That’s a bit high, so I refined it manually. I changed the selection of sprinklers to one kind only, the most efficient pop-up impact sprinkler and changed coverage so I would only overlap a maximum of two sprinkler heads on any part of the property. The automated plan had up to 3 heads watering each spot which is better, more uniform coverage, but the cost is far more than the benefit IMHO. I also simplified the control system, centralizing everything. This dropped the total cost of material to about $1500 making it more attractive.

The web application distributed sprinklers on the property line and every so many feet. That works but, I know from experience that the impact sprinklers scatter water for several feet opposite the stream so you can place them back from the property line. I also know that the trees my wife wants near the property line are “tower poplars” which are somewhat sparse lower down, so I can safely place the trees a few feet from the property line and place a line of sprinkler heads a few feet inside that, shrinking the size of the lot needing coverage. I can also set the sprinklers to about 190 degrees of coverage at the edges to water the line of trees very well. These trees tolerate drought anyway.

By using fewer sprinklers, I can greatly reduce the piping, solenoid valves and cable in the system. The impact sprinklers are much more efficient than continuous sprayers. The impact sprinklers I use now can cover a 70 foot diameter of circle, so a few of them covers the width of the yard with partial overlap. Orbit wants to have each sprinkler head spray the next head but by using just 10 feet of overlap, I can cut the cost of the project way down and everyone gets water. Instead of watering uniformly, I can mow uniformly. My water is also cheap so I can overwater. It all works.

Here’s a guy who has a cheaper DIY design. His cost was also about 4 times less than “standard” just by using the most efficient coverage and tolerating a few gaps.

I don’t dispute that the Orbit planner would produce a better design but for a little better performance, I would be paying several times a larger cost. Also the maintenance of the system would be much larger with more moving parts. Installation will be several times less with my design. The Orbit design called for two miles of pipe. I can do it for about 1/3 of a mile, and since I am the source of labour, that decides it for me. Now to consult with the little woman…

I think this example is indicative of some differences between FLOSS and “commercial” software. FLOSS may leave some gaps but it is far more efficient use of IT. There are always work-arounds for gaps but money/effort once spent is usually gone with non-free software but the effort spent to cover a gap in FLOSS is available for re-use. Both systems get the job done but the costs can be much different. FLOSS also tends to give better performance because it is not trying to do all things for everyone in a particular application. Orbit’s application, no doubt, works for many but it is not optimal for everyone. I could pay the money, hire workers and have Orbit’s plan implemented next week. I can pay a lot less and have my system installed by me eventually. If I have complete control of the design and implementation I can also maintain it more easily. I prefer my way.