Compressed Air – Lifeblood of a Laundry

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Compressed air within a laundry is as important as water. We use Compressed air for controlling our washers to folding the towels yet most never give it a second thought. There is a science to compressed air but this article will deal with some common problems found in laundries and why it is important to correct them in order to provide the Cleanest, driest air possible. Different laundries pose different design features but here are some examples of common problems and solutions.

Start at the beginning of the System. I see a lot of Compressors located in a Boiler/Mechanical Room. You will find that almost all Compressor Manufactures have a Maximum Ambient Temperature limit of below 120 Degs. I find a lot of Boiler Rooms tend to run hotter than this in the Summer. You also would wish to have the Compressor draw in the Coldest (denser) air possible with the lowest moisture content. I live in Florida and have seen several Boiler rooms that were hotter and contained more humidity than the outside air. Now do we move the Compressor? It would be great if possible but if this is not the case I move the Suction of the compressor to the outside. Just up size the Pipe and remount the Air Filter to the pipe outside. If it will see rain or snow, then cover it with an overhang. The compressor will run cooler.

Now the laundry equipment needs the cleanest, driest air possible. The compressor should discharge to an Air receiver. If you have Multiple compressors then pipe Each one with its own pipe to the Receiver. This way they do not pump against each other. What size Receiver? I use a rule of thumb that is one gallon of receiver size for every Cubit foot of air provided. Example – two compressors providing 100 CFM each would be piped to a 200 Gallon receiver or 2 100 gallon receivers. The Receiver is the First location where Water and Debris are removed and where the Air loses some of the temperature caused by compressing air. The air can now be piped to a Primary Filter and then a secondary finer Filter. Then the air can go the Dryer. A large amount of Water and Debris have been removed and the dryer removes the rest of the water. The idea is to protect the dryer coils and size the dryer correctly. If the Dryer is in a Boiler room and has compressors piped straight to it the Dryer will need to be derated due to the high ambient temperature and the high Compressed air temperature plus the Debris and high amounts of water in the Air.

Now that there is Clean Dry air available what size pipe should you use going out to the Laundry? That depends on the Pressure, FLOW Rate required (CFM) and Length of pipe required. When I am looking at a system I look for a 1in pipe to go up by one inch for every 500 CFM of air required and another 1 inch for every 1000 feet of run. An example – 2000CFM required = 1in + 3in for the extra 2000 CFM = a 4 inch pipe would be the size of the main manifold. There are designs with accumulators and I also prefer a Loop system where the pipe runs back to the Main Receiver to prevent “Starving” the components at the end of the system. For brief large draw areas such as Washer Extractors Tilting the use of air tanks as accumulators is a good practice.

When running a length of pipe and the pipe drops to a lower level then place TEE instead of a 90 to continue along a Parallel run with a 6 to 8 inch length of pipe and a small ¼ inch valve to drain off water. This is called a drip leg which will help keep the system clean and dry.

Every time the system needs to go to the Equipment place the “T” pointed up then 180 degrees down to the Equipment. This will help debris and any water that may be in the system from getting to the Equipment. Air controls and components are costly and I see more damage from an air system with problems than any other cause. The water you see spraying from an exhaust or dripping from a cylinder is damaging that component and others.

Last is that Compressed air cost money. Every ¼ inch of leak can equal $10,000 dollars a year or more. It also causes the system to work harder which can be costly in increased maintenance. So take a look at the complete air system in your laundry and see what you can change or plan on next time new equipment is needed. If you have a Vendor that supplies/maintains your air compressors then they can be a valuable resource at the Design, unique requirements and capacity of your system. The return is longer air component life within the laundry and a lower running/maintenance cost of the system.

Mark McLeod – AKA TUNNELTECH

  • laundryboarder said,

    Just want to say I’ve enjoyed and applied many of your suggestions/procedures on the forum.

    Thank you TUNNELTECH!