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Quick Answer
Yes, you can use an air compressor to blow out sprinkler systems as part of winterizing them. Using compressed air is an effective way to remove any remaining water from the pipes to prevent freezing and damage over the winter months. Make sure to follow the proper precautions when using an air compressor for this task.
Using an Air Compressor to Winterize Sprinklers
Blowing out a sprinkler system with an air compressor is one of the main methods used to winterize and protect the system from freezing temperatures. Here are the key steps involved:
1. Turn Off Water Supply
First, locate the shut-off valve for the sprinkler system, usually found near where the main water line enters the home. Turn the valve to the off position to cut off the water supply to the sprinklers. This prevents any new water from entering the system while you blow it out.
2. Open Drain Valves
Most sprinkler systems have one or more drain or blow-out valves located at the end of main lines or zones. Open up any manual drain valves to allow the compressed air to escape along with any remaining water in the pipes.
3. Connect Air Compressor
Use a pneumatic air blow-out kit to connect the air compressor to the sprinkler system. These kits include adapters that thread onto the sprinkler valves and allow you to connect an air hose fitting. Make sure the compressor has an adjustable pressure regulator—40-60 PSI is ideal for blow outs.
4. Blow Out Each Zone
With the compressor running, open each zone valve one at a time and let the compressed air flow through the pipes and out the open drain valves for 30-60 seconds. This forces out the remaining water. Make sure to blow out any drip irrigation lines as well.
5. Drain Above Ground Pipes
For any exposed pipes, open the ends and allow any collected water to drain out. You can also connect a compressed air nozzle to blow air directly through above ground pipes and dislodge any lingering water droplets.
6. Disconnect Compressor and Close Valves
Once finished, turn off the compressor and disconnect it from the sprinkler system. Make sure to close any open drain valves and zone valves. The system is now prepped for winter.
Tips for Using an Air Compressor
Follow these tips to safely and effectively use an air compressor to blow out your sprinklers:
– Use a compressor with at least a 30-gallon tank capacity and airflow of 12-14 CFM. This provides sufficient pressure and volume.
– Wear protective eyewear when using compressed air to blow out pipes.
– Only connect to PVC pipes—do not connect air hoses directly to poly tubing.
– Monitor pressure gauges to avoid excessive pressure. Most residential sprinkler components are only rated to 80 PSI.
– Make sure all valves are fully open when blowing out zones—partially closed valves can rupture under pressure.
– Only run compressors in well-ventilated areas since they produce carbon monoxide.
Benefits of Blowing Out Sprinklers
Using compressed air to winterize your sprinkler system offers several advantages:
– Removes all remaining water from pipes to prevent freezing and cracks.
– Forced air dries out pipes thoroughly to inhibit mold growth.
– Quicker than draining water passively with drain valves.
– Doesn’t require adding RV antifreeze like some winterization methods.
– Allows for winterizing complex systems with multiple zones.
– Compressors can be rented if you don’t have one.
Alternatives to Using an Air Compressor
While air compressors are the most effective blow out method, here are some other options for winterizing sprinklers:
Manually Draining
You can manually open all the drain valves and wait for gravity to drain out any remaining water. This passive draining can take hours and may not remove all water.
RV Antifreeze
Non-toxic RV antifreeze pumped through sprinkler lines will displace water. This method also takes time and antifreeze can be difficult to fully flush come spring.
Shut-off Valve Drainage
Newer shut-off valves for sprinklers have a bleed port that allows water to drain from the valve box below frost level when winterized. But pipes may still hold some water.
Professionally Winterized
Many irrigation companies offer blow out services using professional-grade compressed air systems for more thorough winterization.
Preparing Sprinklers in Fall for Winter
To get your sprinkler system ready for winter, follow this complete fall maintenance checklist:
– Inspect sprinkler heads and nozzles for any damage or clogs. Replace broken sprinklers.
– Flush out sprinkler valves by operating zones to remove sediment.
– Check filter screens on valves and clean out any debris.
– Insulate any above ground pipes with foam pipe insulation.
– Program the irrigation controller to account for reduced watering needs in the fall.
– Turn off and drain the backflow device so water doesn’t remain in the pipes.
– Shut off and drain the water supply line to sprinklers.
– Winterize the system through your preferred method such as blow out with air compressor.
Conclusion
Using an air compressor is generally the most effective way to fully blow out and winterize an in-ground sprinkler system. The key steps involve shutting off the water, opening drains, connecting the compressor, and blowing air through each zone to force out remaining water before it can freeze.
Following proper precautions on air pressure and ventilation provides safe use of compressors. Make sure to also inspect and flush the system in the fall prior to winterization. A thorough blow out with compressed air allows your sprinklers to survive the winter undamaged and saves you from costly repairs come spring.
Frequently Asked Questions
What PSI should I use to blow out sprinklers?
40-60 PSI is the recommended air pressure range for blowing out most residential sprinkler systems. You want strong enough air pressure to displace water, but not so high that you risk damaging PVC pipes and components.
How long does it take to blow out a sprinkler system?
Plan on about 30-60 minutes to blow out a typical residential system depending on the number of zones. Blowing out each zone one at a time for 30-60 seconds is usually sufficient.
What size air compressor do I need to blow out sprinklers?
Look for an air compressor with at least a 30-gallon tank and 12-14 CFM airflow capacity. Smaller portable compressors often don’t provide enough sustained airflow.
Can I rent an air compressor to blow out my sprinklers?
Yes, many home improvement stores like Home Depot and Lowe’s rent suitable air compressors for blow outs and other uses if you don’t have your own. Rental fees are usually around $50 per day.
Should I blow out the backflow preventer too?
Yes, use compressed air to blow out any trapped water from the backflow preventer and its connected pipes last before disconnecting the compressor. Shut off and drain the backflow device for winter.
| Zone | Blow Out Time |
|---|---|
| Front lawn sprinklers | 45 seconds |
| Back lawn sprinklers | 1 minute |
| Flower bed sprinklers | 30 seconds |
| Shrub sprinklers | 45 seconds |
| Side yard sprinklers | 1 minute |
This table provides example blow out times for each zone when using an air compressor to winterize an in-ground sprinkler system. The times can vary based on the size and complexity of each zone.