# Sprinkler blowout air compressor recommendation



## Prospect

Trying to figure out what size compressor I need to winterize my sprinkler system. CFM, SCFM, tank size etc.. starting to get confused and need some people who do it help with recommendations


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## crazymas0n

Don't mind me, just gonna follow this thread as I'm also curious. Wondering if it's even possible with a 120V portable unit.


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## bmitch05

@Prospect I use an 11 gallon Campbell Hausfeld (WL600602AJ) that will do 8.1 SCFM @ 40 PSI which I think does a pretty good job of blowing out all of the moisture. There are quire a few used compressors on the second hand market , you want to use a compressor that will do at least 5 CFM.


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## quadmasta

The best rig I've seen for smaller or lower CFM compressors was something AvE did a while back. I tried to look for the video but I guess he took it down. He put an adjustable pressure switch on the output of his compressor and had it open when the tank pressure was 100PSI and close when it was 90PSI. It let it have a powerful blast of air that'd recharge the tank and have another powerful blast when the tank pressure went back up.


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## Prospect

I came across a 2015 Campbell Hausfeld 20 gallon compressor, 2 hp, 5.5 cfm @90psi on Craigslist for $260 at a pawn shop but when I went to test it out, the regulator leaked after it came to full tank psi. Bummer
I was seriously contemplating buying a used compressor but it's looking like Home Depot has a 30 gal 175 psi 5.1 scfm @90 psi with 2 year warranty for $349. I still have a few weeks before I need one but I'm leaning towards a new unit with warranty unless something too good pops up


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## Biggylawns

I'd check facebook marketplace daily as there are killer deals on there. Just looked and within an hr ride of me there were (3) 26 to 30 gal compressors for 125 or less. Then just check out each unit's specs online.


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## hsvtoolfool

quadmasta said:


> He put an adjustable pressure switch on the output of his compressor and had it open when the tank pressure was 100PSI and close when it was 90PSI.


My understanding of irrigation systems is to *avoid air pressures above 40 PSI* when clearing the lines. High CFM is used to blow out the water instead of high PSI. The pop-up heads can be damaged by high pressure and it's probably bad for the valves too. High flow at lower pressure does the job.

The problem is that high CFM compressors are large and expensive. But we can still get 'er done with the typical 110V 15+ gallon portable compressors. I strongly doubt a small pancake compressor for nail guns will do the job.

I have an old Sears "oilless" 110V 15 gallon compressor. I set the pressure *output* at 40 PSI, let the tank fill for several minutes to its max at 120 PSI, "activate" an irrigation valve, then slowly crack open the air to blow out the water. The air flows for about 30 to 60 seconds before the tank pressure drops too low. I repeat this tedious process on each zone until I'm satisfied most of the water is gone. It usually take about an hour for my 5 zones (3 lawn + 2 drip line).

I do this every year at my house and at my buddies house. This task is really hard on the poor 110V compressor motor which runs continuously and gets pretty darn hot. No doubt he and I will kill this little guy before too much longer. But I don't care because it only cost about $100 back in 1992 and I'm ready to upgrade to a bigger and better compressor. Something I can use to sandblast and paint cars.

I bet that a big, 80 gallon 5 HP 220V two-stage compressor capable of about 15 CFM could finish each zone with a single sustained blowout and have almost zero recovery time before the next zone. You'd be finished in 10 minutes instead of an hour. Nice, but not required.


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## bmitch05

hsvtoolfool said:


> quadmasta said:
> 
> 
> 
> He put an adjustable pressure switch on the output of his compressor and had it open when the tank pressure was 100PSI and close when it was 90PSI.
> 
> 
> 
> My understanding of irrigation systems is to *avoid air pressures above 40 PSI* when clearing the lines. High CFM is used to blow out the water instead of high PSI. The pop-up heads can be damaged by high pressure and it's probably bad for the valves too. High flow at lower pressure does the job.
> 
> The problem is that high CFM compressors are large and expensive. But we can still get 'er done with the typical 110V 15+ gallon portable compressors. I strongly doubt a small pancake compressor for nail guns will do the job.
> 
> I have an old Sears "oilless" 110V 15 gallon compressor. I set the pressure *output* at 40 PSI, let the tank fill for several minutes to its max at 120 PSI, "activate" an irrigation valve, then slowly crack open the air to blow out the water. The air flows for about 30 to 60 seconds before the tank pressure drops too low. I repeat this tedious process on each zone until I'm satisfied most of the water is gone. It usually take about an hour for my 5 zones (3 lawn + 2 drip line).
> 
> I do this every year at my house and at my buddies house. This task is really hard on the poor 110V compressor motor which runs continuously and gets pretty darn hot. No doubt he and I will kill this little guy before too much longer. But I don't care because it only cost about $100 back in 1992 and I'm ready to upgrade to a bigger and better compressor. Something I can use to sandblast and paint cars.
> 
> I bet that a big, 80 gallon 5 HP 220V two-stage compressor capable of about 15 CFM could finish each zone with a single sustained blowout and have almost zero recovery time before the next zone. You'd be finished in 10 minutes instead of an hour. Nice, but not required.
Click to expand...

This is something to consider, you want to keep the air pressure much lower than 90PSI, the highest volume I will allow is about 60 PSI.. This could definitely damage the system. The reason I like the Campbell Hausfeld over other options it can supply 8.1 SCFM at only 40 PSI... this is roughly the same pressure as my water supply line so I don't run the risk of damaging any of my lines, valves, or heads. My system has 9 zones and I had it closed down in about 20 minutes, it also helps that I have a wireless irrigation controller too, which only makes this job that much easier. I found my CH on FB marketplace for $100 used. I also use it for inflating tires, painting, brad nailer, nail gun.. etc. Its a great unit!


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