Retrofit Options:^[i]

There are two main retrofit options to reduce water use associated with existing laundry equipment: water reuse/recycling and ozone systems.

 Water Reuse/Recycling

Simple or complex recycling systems can be added to coin- or card-operated washers, multi-load washers, and washer extractors to recycle a portion or all of the water for reuse in the next wash. Simple recycling systems recover discharge from the final rinse in a multi-cycle operation for use in the first rinse of the next cycle. The water from these systems rarely needs treatment prior to reuse, so potential water savings is 10 to 35 percent. Complex recycling systems treat the reclaimed water from wash and rinse cycles for use in all cycles of the next load and can save more than 85 percent of water used. Complex recycle systems usually require water treatment before reuse. Be sure to evaluate space constraints when considering water reuse/recycling options. Space may not be available to accommodate additional recycling equipment or storage tanks. Because recycling may also require adjustments in chemicals and detergents, contact the chemical supply vendor in any retrofit planning.

Ozone Systems

Ozone systems can be installed on all types of existing commercial laundry machines as retrofits, although they are not as common as a retrofit for tunnel washers. Ozone systems generate ozone, which is injected into the wash as a powerful oxidant that reacts with dirt and organic materials. It also provides disinfection and whitening properties. Ozone can allow for reduced water temperatures, typically to 80oF, which saves energy. It also can reduce the amount of detergents and other chemicals needed, lessening the amount of rinsing required. Ozone systems work well on lightly soiled laundry, but they are not recommended for heavily soiled laundry. For heavily soiled laundry, conventional washing, detergents, and hot water work best.

Savings Potential

Water savings can be achieved through retrofitting existing laundry equipment to recycle wash water or reduce the amount of water required for rinsing, or by replacing existing laundry equipment with more efficient equipment. To estimate facility specific water savings and payback, use the following information.

Coin- or Card-Operated Washer or Multi-Load Washer Retrofit

Use the following information to estimate water savings and payback potential that may be achieved with recycling or ozone retrofits. Water savings can vary based upon the water use and use patterns of the existing laundry equipment and the type of retrofit selected.

Current Water Use

To estimate the current water use from a commercial coin- or card-operated washer or multi-load washer, identify the following information and use Equation 1-1:

·       Washer’s water factor in gallons per cycle per cubic foot of capacity. Coin- or card-operated washers installed since the early 1990s will have a water factor of 9.5 gallons per cycle per cubic foot of capacity or less.

·       Capacity of the washer.

·       Average number of cycles per load. The number of cycles refers to the number of times the washer is filled with water. There may be one or two wash cycles and one or two rinse cycles in typical coin- or card-operated washers or multi-load washers.

·        Average number of loads per year.

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Equation 1-1. Water Use of Commercial Coin- or Card-Operated Washer or Multi-Load Washer

(Gallons per year)

= Water Factor x Washer Capacity x Number of Cycles x Number of Loads

Where:

• Water Factor (gallons per cycle per cubic foot capacity)

• Washer Capacity (cubic feet of capacity)

• Number of Cycles (cycles per load)

• Number of Loads (loads per year)

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Water Savings

Studies have documented water savings for retrofits with a simple recycling system, retrofits with a complex recycling system, and ozone system retrofits.

Table 1-2. Potential Water Savings from Commercial Laundry Retrofit Options