Minimum size compressor for irrigation blow out?

[Gus]

My inlaws just bought a new house and are considering doing the blow out themselves. What do you think would be the smallest compressor HP and Tank volume to do a good job? I don't have any info on number of heads per zone or number of zones (They have not moved in yet) It is a 2.5 acre lot and the whole thing is irrigated. It is also on a well. Thats all the info I have at the moment.

Any advise is appreciated.

[solbes]

You want a good volume of air at medium pressure. The higher the flow the better.

That being said, every year I limp along with a vintage low Hp compressor and it still does the trick. Takes me over 2 hours though because I'm constantly waiting for the unit to rebuild pressure. I go through every zone three times to make sure the heads and lines are dry. I keep waiting for it to die so I can get a larger unit, but if it works I can't justify a new one.

[echotrail]

I rent a 8 hp compressor and it has enough pressure for the job without waiting for buildup . I blow out the six zones to get most of the water out and then go around again to finish them off. It takes me 45 minutes at most, but I'm only doing 1/3 acre.

[18 inch Crappie]

Pay the $50 to have it done right and save yourslef the pain. If you do not get all the water all out it will cost you more in the spring when you are replacing the backflow and trying to find the busted line under ground.

[echotrail]

A homeowner who has a in ground system should know how to winterize the lines. If you don't have the time or don't want to thats fine but at least know how. I had a system installed in Sept. 1987 and paid to have the lines blown out. (I Didn't know how) He wanted to finish the job fast (More jobs, more money) and pushed in too much air and blew out two heads. He said "Must have been bad heads and your warranty should cover them". The heads were only 7 weeks old and worked fine. The second year a different guy winterized the system and blew a head out. He must have pushed it back into the ground and I didn't notice it until spring. He said "The spring thaw must have pushed it up". DUH! IF ALL I CAN FIND IS LIARS OR CON ARTISTS IT'S TIME TO LEARN HOW. Since then I've done it myself. No blown heads, no frozen lines. The hired guy isn't going to admit fault and you'll end up doing or paying for repairs anyhow.

[Dave]

I use a 33 gallon Craftsman and blow out each zone three or four times; until only air comes out. $269 for the compressor and I've winterized three or four times so, it's over half paid for itself. Nice to have a compressor for other uses as well.