Energy Waste in Commercial Laundries

By Earl Winter

Laundry efficiency comes in many forms, including equipment longevity, textile product life, reduced energy costs, water / chemical usage, labor savings, etc.

While every laundry manager knows that it cost more per pound to wash partial loads vs full loads, many do not understand another huge downside to under-loading an open pocket washer / extractor. While common sense would lead one to believe that overloading a washer / extractor could cause machine damage, the exact opposite is the case. Under-loading is the curse of an open pocket washer / extractor and damage is very predictable. If you under-load an open pocket washer once, you may seriously damage the machine. If you make a habit of under-loading this type machine, serious damage is inevitable. We have seen a single repair cost over $25,000 on nearly new equipment.

The problem is in the machine’s inability to distribute small loads around the cylinder. In the case of walk off mats and incontinent pads, even distribution is a problem even with full loads due to the materials used and their inability to slide past each other. With normal linen loads you should never wash loads that are less than 70% of the full load rating of the machine. In the case of mats and pads, some manufacturers recommend loading the machine to 125% of full load capacity.

So what can you do to process smaller loads? There are four basic choices. You can wait until you have more product, you can process it in a smaller machine, you can process it in a split pocket machine, or you can wash some clean product with it to make up the weight. The inefficiency of washing clean product again is much less costly than the long term costs of under-loading an open pocket washer / extractor.

A common practice in many laundries that dramatically shortens textile life stems from the way dryer operators determine if a load is dry. Opening the door on a dryer and feeling the linen to see if it is dry not only wastes time and energy, it has a high degree of potential to damage the linen.

The way nearly all gas dryers work is to start off on high fire and modulate the burner down to a lower firing rate as the load gets dryer. When the dryer is stopped near the end of its dry cycle to check the linen, then restarted to finish drying, most dryers will again start off in high fire. The nearly dry linen will be damaged by the excessive heat, will feel stiff to the touch, may appear scorched, and will certainly be a candidate for the rag bin prematurely.

All dryers come with exhaust temperature indicators. As the linen gets dryer, exhaust temperature increases. There is a corresponding exhaust temperature to dry linen or linen that is as dry as you desire it to be. Learning what that temperature is and shutting down the dryer when that temperature is reached is a simple process. The door should never be opened until you take the linen out.

When energy costs become the focus of cost reduction, fuel and water are often the priorities, and except for turning off lights, people seem resigned to not being able to do much about electrical costs.

The more efficient plants operate around .08 kw / lb, and sometimes achieve .06 kw / lb levels. The cost of this electricity varies dramatically with region, but an average cost in the year 2000 was approximately $0.08 per kw. To do the math for you, if you produce 250,000 lbs / week, are paying the average price per kw, and are using .09 kw / lb, you are spending $10,000 more per year than a plant using .08 kw / lb. I have seen plants use .16 kw / lb, or $80,000 / year more than an efficient plant. Obviously, if you are paying more per kw/hr, or producing more than 250,000 per week, the news is even more grim.

Now, if your plant is not one of the more efficient and you want to add this excess cost back to the bottom line, the following are some areas to look at.

• Shut down production equipment when not in use. An unused iron running with roll pressure on typically uses 15 kw / hr or more in addition to the cost of keeping it hot and wearing out the pads and covers while producing nothing.
• An iron with clean chests that is waxed every two hours of operation, not only produces higher quality and more throughput, but uses less electricity than an iron that is only waxed once or twice a day. I have witnessed ironer motor electrical use drop 20% by simply waxing the iron.
• We all know that we should turn lights off when not in use, but we often underestimate the cost of laxity in this area. This not only applies to restroom and storeroom lights. It is not uncommon to be in a plant with all of the plant lights still on, when production has been shut down for hours.
• Turn all fans off before going home.
• Space heaters have electric fans. Make sure they are shut off when not needed.
• Running a washer or dryer half loaded uses twice as much electricity / pound as a properly loaded machine.
• Is a 75 or 100 hp air compressor kept running longer than necessary, or used when we are running only a couple pieces of production equipment? This will drive your kw / lb way up. To put this in perspective, assume you have two 100 watt light bulbs in your restroom which you religiously shut off when not needed. The air compressor is equivalent to leaving the lights on in up to 500 restrooms.
• Buy a programmable control for your air conditioning and heat. They are cheap and will prevent you from heating and cooling the office areas all night when no one is there to appreciate it.

For the sake of brevity, it is impossible to include all energy saving possibilities here, but here are some additional tips that may be of use to you.

1. Lock out excess equipment. Using equipment just because it’s there cost more in maintenance, energy, and manpower.

2. Use gas dryers instead of steam if possible. Steam is less efficient and steam dryers are using energy even when sitting waiting to load or unload. Lock out steam dryers if possible.

3. If you only need equipment for a partial day, don’t warm it up until an hour before you need it, and shut it down completely when finished with it.

4. Coordinate your production day to optimize the boiler operation. Steam is needed for the washroom, flatwork and garment departments. Weigh the benefits of staggering these departments working hours against the extra hours need for boiler operation.

5. Make sure supervisors have time to supervise. For example, a supervisor loading washers doesn’t have time to ensure the extractor operator isn’t shortcutting extraction times, resulting in increased drying times and slower ironer speeds. Likewise, a supervisor pushing carts and slings doesn’t have time to effectively coordinate ironer usage, enforce waxing standards, etc.

6. Do not defer needed equipment repairs because of budget concerns. The defective equipment will result in longer working hours due to equipment shortage, and therefore increased labor and energy costs. It normally affects quality as well, snowballing into extra rework.

7. Under-loading washers is such a huge waste, it should be the highest priority issue in the plant. Not only do gallons per pound dramatically increase due to less pounds being produced, the actual water consumption for each load significantly increases due to less goods in the machine to fill the space. The machine is going to fill to a specified number of inches of water whether there is anything else in the machine or not. More water, more energy to heat the water, more chemical usage, higher sewer charges, increased labor, increased machine usage to produce the same poundage, increased boiler hours, and the potential bottleneck in the washroom effects efficiency elsewhere in the plant.

8. Make sure your dryers are performing efficiently. There should be no plastic buildup in the basket, door and basket seals must be in good condition, lint must be routinely removed from air intake screens and from lint collectors, etc.

9. Ensure waste heat reclaimers are kept clean and in operation. This device saves $1500 per degree of extracted heat per year.

10. Don’t ignore even a single leak. Even small leaks cost considerable dollars in energy usage. For example, a 1/8 th inch air leak cost approximately $1500 per year extra just for the electricity to run the air compressor. When you have pressurized air, steam, gas, and water trapped in pipes and equipment in an ever changing environment, leak development is a daily fact of life. If you ignore a few, you will quickly have many.

A walk around the plant with eyes and ears open will invariably find other energy wasters, if you are not one of the plants already achieving great success in this area. Key areas are good communications between operations and maintenance so that machinery can be shut down in a timely manner, and scheduling of production to allow for maximum shutdown time on unnecessary equipment during the day. It is well worth the effort.

Earl Winter is a past Engineering Vice President for a large Textile Rental Co., and is currently the President of Earl Winter Engineering Associates, Inc. He has over 40 years of experience in maintenance engineering management, much of this in the laundry industry. He has been the Director of Services for a large laundry equipment distributor, and helped develop and teach the U.S. Navy’s school on commercial laundry equipment. You can learn more on his web site www.earlwinter.com, or call him at 770 402-7820. Email at earl@earlwinter.com

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