If your business relies on an air compressor, winter can be a difficult time. Freezing temperatures risk blockages, breakdowns and higher running costs — unless you’ve taken steps to avoid these problems. Here, we’ll explain what’s different about winter operation and what can be done to prepare.
You Rely on Your Air Compressor
In many factories and processing plants — as well as on farms, ski slopes and elsewhere — compressed air is as important as electricity. It’s a power source for hand tools, drives actuators and mechanisms, and transports powders. It’s also used in applications as diverse as crop spraying, venting silos and making snow.
In all of these applications, no compressed air means no work. That usually hits the financial bottom line. Low temperatures, which means below 45 degrees Fahrenheit, can cause a range of problems for a compressor, and even stop it from running.
To avoid this and other temperature- and environment-related problems, some businesses place their compressors in an air-conditioned environment, but those are a minority. In many cases, the compressor is in an unheated shed or even outside and exposed to the elements. If that’s the case for yours (and ambient temperatures may drop below 45 degrees Fahrenheit) brace for problems.
What to Expect With an Air Compressor in Winter
Low temperatures cause four main problems:
- Oil becomes more viscous
- Elastomers (including rubber) become less flexible
- Water condenses out of the atmosphere
- Water contracts and then expands as it freezes
Here’s a deeper dive into each of these:
- Oil viscosity: Oil becomes thicker at lower temperatures. In an oil bath-design rotary screw compressor, that means a lot more drag for the motor to overcome. Current will become greater. That can lead to breakers tripping, with knock-on effects for the compressed air supply.
- Elastomers: Rubber and other elastomeric sealing materials get harder and less flexible at low temperatures. For hoses, this means an increased risk of crack; for seals, more chance of leaks.
- Condensation: The quantity of water vapor in atmospheric air is proportional to temperature. Hot air holds more, which is why tropical regions have that steamy feel. When air cools, some of that water condenses. If temperatures are above freezing, it appears as dew; below freezing, it’s frost.
This condensation will cause corrosion on exposed metal. It’s a particular problem inside electrical enclosures where it can make contacts stick, delaminate printed circuit boards and create short circuits.
- Water: The maximum amount of moisture that air can hold is inversely proportional to pressure. Thus, drawing and compressing atmospheric air — which is what a compressor does — squeezes/removes some of that water. Compressors incorporate condensate traps to stop this water from getting into the distribution systems. Most will also have dryers to remove more moisture.
When temperatures drop below freezing, water in condensate traps and elsewhere will turn to ice and create blockages.
A second problem relates to water density. This peaks at 39.2 degrees Fahrenheit, meaning water expands at temperatures on either side. When ice melts, expansion can burst hoses and crack water fittings.
Best Practices for Running an Air Compressor in Winter
Ideally, the compressor should be installed in a room where ambient temperatures will stay above 45 degrees Fahrenheit. If that isn’t possible, it should be winterized by taking the following actions:
- Ensure oil is of a suitable grade or viscosity for low temperature running
- Insulate and/or heat condensate traps and water lines
- Close louvers admitting air into the compressor enclosure
- Inspect and replace hoses and belts as needed
- Regularly check condensate traps and drains for water
All of these will help you avoid problems when running an air compressor in winter. However, a better approach is to anticipate low-ambient temperatures when choosing a new compressor.
Ask About Low-Ambient Options
At Kaishan Compressor USA, LLC, we understand it’s not always possible to locate your compressor in a warm location. For that reason, we offer a low-ambient option. This comprises an electrical enclosure heater, a sump heater, control line tracing heating/insulation and independently controlled thermostats. Here’s more detail:
- Electrical enclosure heater: By keeping the electrical cabinet warm enough to prevent condensation, this protects against corrosion, stuck contacts and other damage.
- Sump heater: This stops the compressor oil from becoming too viscous. It enables easier starting and reduces energy consumption when the compressor is running.
- Trace heating/insulation: Trace heating means running an electrical heating element, (often it’s a tape) along pipes or other surfaces that need just a little warmth to prevent condensation freezing. This can be applied singly or in conjunction with pipe insulation for better results at low temperatures.
- Thermostats: These are used to turn on and off local heating as needed.
Winter Applications for Air Compressors
While factories and process plants will run their compressors year-round, there are some seasonal applications. Two interesting ones are winterizing water lines and making snow.
Winterizing entails blowing out water lines with an air compressor. This is done to prevent cracking when any trapped water thaws after freezing. Irrigation and sprinkler systems are prime examples, but it may also be done in buildings that will be left without heat through the winter.
As skiing enthusiasts may know, snowfall is increasingly unpredictable. Because of this, to avoid disappointed guests, most ski resorts now make snow rather than relying on nature. Snow machines work by blowing compressed air through a stream of water. The velocity breaks the water into small particles and the pressure drop causes rapid freezing with the resulting particles being blown over the slopes.
Recap: Using an Air Compressor in Winter
Unless prepared appropriately, a compressor will perform differently — or simply won’t work — in winter. If it’s not possible to place the compressor in a warm room, follow the advice given above to protect it against low temperatures. If purchasing a compressor that will be exposed to cold, ask about low-ambient options.
Understand Your Air Compressor Options
Using a compressor that’s not matched to the application will increase operating costs and may result in an uneven or inadequate supply of compressed air. Kaishan manufactures high-quality air handling products including compressors that go from compact, belt-driven models to powerful, direct-drive, two-stage units.
A Kaishan product specialist can help you choose the right compressor for your application. Contact us today to start the conversation.