Laundry Facilities

General

Commercial Washers

Laundries in commercial applications are typically individual "mom and pop" Laundromat® businesses or are centralized laundry facilities found in the military, hospital, multi-family, hotel/motel, and academic buildings.

Hospital laundry facilities typically use large commercial grade equipment. The hot water is supplied from a central boiler plant that also supplies the hot water for all the hospital's other needs, including kitchen, space heating, hydrotherapy, etc.

Centralized laundry facilities in residential facilities (military housing, multi-family, hotel/motel, and academic buildings) are installed to provide residents with the best conveniences. Typical bundled amenities can include washing, drying and pressing services, card payment programs, and door access systems. They also seem to have value in resource conservation.

In a comparison of washing machine usage rates in rental units versus that of coin-operated machines in common area laundry rooms, an independent survey by a national research firm found that each in-apartment unit washer used an average of 11,797 gallons of water annually. Coin-operated machines in common area laundry rooms, on the other hand, averaged water usage of only 3,270 gallons a year per apartment unit served. This difference of some 8,500 gallons per apartment per year adds up to significant water savings. One nationwide research survey showed that residents with washers in their apartments do many more, smaller and less-efficient loads than residents utilizing a common area laundry room. The study found that, on average, an apartment property with in-unit washers will use 3.5 times more water for laundry than an identical property with common area laundry rooms. Water isn't the only resource being wasted. There's also the attendant gas and electricity as well as massive amounts of extra sewage generated by in-apartment laundries.

Even modest laundry rooms can be made appealing, attractive amenities to a property if just a few design basics are kept in mind. It may be as simple as adding a few potted plants and a small television, or maybe some graphics for the walls. Some properties are combining their laundry facilities with recreation or exercise rooms or placing them near play yards or swimming pools. The first and most important principle is to make it convenient. The Multi-housing Laundry Association (MLA) suggests placing laundry facilities no more than 250 feet from the apartments they will serve.

For many properties, this suggests several smaller rooms rather than one large, centralized one. Laundry rooms should be along main traffic patterns, be well lit and have adequate visibility to ensure security. They must be kept clean and the machines in good working order. They should be affordable. A few practical features such as folding tables or hanging racks and good, comfortable seating will go a long way toward pleasing residents. Another trend gaining momentum is a movement toward coinless laundry rooms with washers and dryers activated by "smart" cards issued to residents.

Laundromats®

These are localized small businesses, typically located in urban areas where there are not many in-apartment washing and drying machines. To improve business, the operators of even modest laundry rooms can make them more appealing. It may be as simple as adding a few potted plants and a small television, or maybe some graphics for the walls.

Water Heating

Coin-Operated Laundries (small domestic machines in coin laundries) or apartment house laundry rooms have a wide range of draw rates and cycle times. Domestic machines provide wash water temperatures (normal) as low as 120°F. Some manufacturers recommend temperatures of 160°F; however, the average appears to be 140°F. Hot water sizing calculations must assure supply to both the instantaneous draw requirements of a number of machines filling at one time and the average hourly requirements.

The number of machines that will be drawing at any one time varies widely; the percentage is usually higher in smaller installations. One or two customers starting several machines at about the same time has a much sharper effect in a laundry with 15 or 20 machines than in one with 40 machines.

A simultaneous draw may be estimated as follows:

Number of Machines % of Draw
1 to 11 100%
12 to 24 80%
25 to 35 60%
36 to 45 50%

Possible peak draw can be calculated from formulas given in the ASHRAE Applications Handbook chapter on Service Water Heating.

Commercial laundries generally use a storage water heating system. The water may be softened to reduce soap use and improve quality. The trend is toward installation of high-capacity washer-extractor wash wheels, resulting in high peak demand.

Laundries can normally be divided into five categories. The required hot water is determined by the weight of the material processed. Average gallons per pound per hour of hot water requirements at 180°F are:

Category Average gal/lb·h
Institutional 2 gal/lb·h
Commercial 2 gal/lb·h
Linen supply 2.5 gal/lb·h
Industrial 2.5 gal/lb·h
Diaper Service 2.5 gal/lb·h

Total weight of the material times these values give the average hourly hot water requirements. Peak requirements must also be considered; for example, a 600-lb machine may have a 20-gpm average requirement, but the peak requirement could be 350 gpm.

In a multiple-machine operation, it is not reasonable to fill all machines at the momentary peak rate. Diversity factors can be estimated from formulas given in the ASHRAE Applications Handbook chapter on Service Water Heating.

Other Technology

Ozonation - Ozone is created by a high voltage electrical field, typically generated by a corona wire. Surrounding air is charged, producing ozone gas, which is a highly effective oxidant. Ozone oxidizes wash water, reacting with soil molecules and turning them into soluble soils. Ozone has a 20-minute half-life in water, reverting to oxygen. It is best suited for lightly soiled textiles, such as sheets, towels, pillowcases, and blankets. It can be retrofitted to existing washers and is cost-justified in geographic areas with high volume water costs or environmental surcharges.

Environmental Benefits:

  • Reduces the amount of detergent required for cleaning.
  • Allows the reuse of wash water, thereby reducing the volume of water used.
  • Reduces detergent and the effluent levels in wastewater.
  • Whitens without bleach, so no chlorine residue is left.

Additional Benefits:

  • Reduces chemical/detergent costs
  • Lowers fuel costs because lower temperature wash water requires less heating.
  • Lowers sewer charges because of lower levels of effluents and detergents in wastewater - important in geographic areas with high sewer costs.
  • Extends the life of textiles because of a gentler means of cleaning.

Drawbacks:

  • Heavily soiled items or certain stains may require rewashing
  • Does not work in hot water

Best Applications:

Laundries in nursing homes, hospitals, prisons, and universities.

[Source: Commercial Environmental Action, The UNIMAR Group, Ltd.]


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