Whirlpool Commercial Laundry
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Location, Design and
Construction Recommendations


LOCATION AND DESIGN

The primary design consideration in locating laundries should be the convenience of the residents. The laundry room should be near elevators or stairs, or other main traffic areas. Common-area laundry rooms should not be located in secluded areas of buildings or projects. The location of the laundry room or rooms will depend upon the size and type of project and the number and composition of families.

Special attention must be paid to design in order to eliminate screened areas. To assure that all laundry areas are visible from the corridor, corridor walls should be of glass or contain glass panels. For smaller laundries, a door of approved glass may afford the necessary visibility. Change makers and soap dispensers, if used, should be placed where they are visible from the corridor.

Other design considerations relate to laundry equipment and its arrangement. There must be adequate space for the equipment, for working, for passage and for equipment servicing. Tables of adequate size for folding laundry should be provided as well as sufficient numbers of washers and dryers. The total number of pieces of equipment will ultimately determine the size of the laundry. The typical washer is 27"-29" wide and 28-1/4" deep; the average single-load dryer is 27"-35" and 28-1/4" deep; the average for single-load dryers will also accommodate stack dryers. The average double-load dryer is 34" wide, 37-1/2" deep and 72" high.

  1. Determine the size of the laundry room by allowing a minimum of 25 square feet per machine.
  2. Do not provide raised concrete bases for top-loading equipment. However, some front load washers do require a raised base.
  3. Floors should be concrete with a troweled finish and sloped toward the floor drain. At least one floor drain should be provided per laundry room.
  4. Wash tubs are not required as their use often results in water overflow. However, if they are installed, provide adequate space for them and for the residents using them. Such space should be in addition to that recommended for each machine.
  5. Provide a minimum clearance of 8' between floor and overhead pipes.
  6. Locate dryers on outside walls. Long ducts increase installation costs and are less effective for proper venting.
  7. If fewer than five pieces of laundry equipment are installed, place them side by side.
  8. Provide sufficient lighting, preferably fluorescent. Fluorescent lighting provides 2-1/2 times the lumens obtained from incandescent lighting (i.e., a 40 watt fluorescent is equal to a 100-watt incandescent).

EQUIPMENT

The type and number of washers, dryers and other equipment required, will depend upon the family composition of the occupants, the number of apartments to be served, the presence or absence of children and the number of laundry rooms in the building.

Washers recommended
Energy-efficient, 14-16 lb., heavy-duty commercial washers are recommended.

Dryers recommended
There should always be one energy-efficient, single-load dryer for each washer. When more than one dryer is required in a laundry room, stacked dryers may be used. Double-load dryers are less energy-efficient and may slow the laundry completion process when used to dry less than a double wash load.

Use the following guidelines to determine equipment needed for each laundry room location. The number of machines required are affected by the following:

  • Resident profile (families, singles, elderly)
  • Price charged (low price encourages usage)
  • Proximity of units to laundry rooms
Equipment Guidelines
Predominant Resident Profile* Washers and Dryers per using unit**
Families 1 pair W/D per 8-12 units
Young Working Adults 1 pair W/D per 10-15 units
Older Working Adults 1 pair W/D per 15-20 units
Students 1 pair W/D per 25-40 students
Senior Citizens 1 pair W/D per 25-40 units
* These figures are based on the predominant resident profile. Adjust according to your particular profile mix.
** Determine using units by adding together all units without an in-unit washer/dryer and half the units with in-unit laundry connections.

PLUMBING

Washers
It is necessary that waste water be properly drained in order to avoid unpleasant odors from bleach and detergents. Washers should not be drained into tubs because of the possibility of overflow. Water lines should be sized according to the number of washers in the area. Although local codes vary, below are some useful hints.
  1. Install 3/4" copper pipe with 3/4" hot and cold draw cocks for each washer. Behind each draw cock, install a check valve where code requires.
  2. Install controls to insure that the hot water temperature remains between 120 degrees and 140 degrees Fahrenheit.
  3. Maintain cold water temperature at not less than 35 degrees Fahrenheit.
  4. Maintain water pressure between 20 and 120 psi at the machine.
  5. Provide minimum volume flow of not less than 4-1/2 gallons per minute.
  6. Install one 60-80 gallon quick recovery water heater or equivalent for every two washers; add 20 gallons for each additional washer unless ample hot water is provided from a central source.
  7. Drain each washer into a 2" cast iron, PVC, or copper standpipe 3' high. Trap each standpipe. Provide "clean out" access.
  8. If laundry rooms are located on various floors, use check valves with 3/4" adapters on the top of standpipes. (This is desirable, but not required in single, centralized laundry rooms.) Connect standpipes to 4" drains.
  9. Install a floor drain (minimum 2") in the center of each laundry room to catch any water overflow. Floor must be pitched to floor drain.
  10. Join all piping facilities by connectors sufficiently strong for the design conditions.
Recommendations for Gas Dryers
Single load
  1. Install a properly sized main gas line for the appropriate number of dryers in the laundry room. A qualified engineer or laundry operator should do this.
  2. Install a 3/4" gas line on the wall for connection to the back of the dryer. Terminate it 28" off the floor with a 3/4" T, 6" drip cap, and 3/4" gas cock. Further reduce to 3/8" gas line for individual dryer connection.
  3. Tap off 3/4" lines for additional dryers and install as above.
Double load
  1. For one or two double-load dryers, install as recommended above except locate the gas cock 5' above the floor.
  2. For more than two double-load dryers, run a 2" main gas line into the laundry room. Reduce to a 3/4" T and 3/4" gas cock 5 feet above the floor for each dryer.
  3. Where bottled gas is used, follow the specifications of the local gas company.
ELECTRICAL REQUIREMENTS

Electrical codes (as in plumbing) vary greatly from area to area. Following are some hints you may find useful.

Install 208-240 volts for electric dryers and provide four wire power connections. The standard heating element provided for 240 volts is 5350 watts. 1500-watt heating elements are available for 110 volts. Refer to manufacturers' specification sheets for detailed information.

Since a drop in voltage has a direct effect on the amount of heat produced by the heating element, wires should be sized in relation to the length of run.

Recommendations
Washers and Gas Dryers
  1. Each washer should be installed on individual two wire, plus ground wire (No.12) volt branch circuits with 15-amp circuit breakers.
  2. All receptacles shall be equipped for a three-prong, polarized plug.
Single-load Electric Dryers
  1. Provide separate circuits from the main panel to each dryer. On 240-volt, AC single-phase circuits, the two hot leads must be protected with 30-amp circuit breakers.
  2. Use a 240-volt circuit and the following wire sizes: up to 60 feet, No. 10 wire; 60 to 100 feet, No. 8 wire; over 100 feet, No. 6 wire.
  3. All dryers should be grounded according to local code requirements.
VENTING

The most overlooked consideration in laundry room preparation is dryer exhaust. Venting refers to the passage or provision of a natural airflow. Both gas and electric dryers must get rid of hot air, water moisture and lint particles. This is not a natural flow: hot air wants to go up, water and lint want to go down. The least obstacle in the exhaust system will reduce the dryer efficiency. Wherever possible, dryers should be vented individually to the outside.

Recommendations
Single-load Dryers (treat manifold of "stack dryers" as two dryers)
  1. Laundry room layout should start with dryer location - the shortest vent run from dryer to outdoor termination is always the most efficient.
  2. Individual dryers require a 4" round, rigid metal pipe equipped with a full flow vent hood (with damper). Do not terminate next to in-window air conditioners or "resident use" areas.
  3. When possible, "in-wall" vents should be round and always rigid metal pipe.
  4. Elbows or changes of direction in vent pipes create air turbulence and resistance. Double elbows restrict airflow. Each elbow is the equivalent of 8 feet of straight run, double equals 15 feet. Most dryers can operate with the equivalent of 40 feet of straight lateral 4" pipe.
  5. Manifolding of two or more dryers is most efficient with a gradual upsizing that maintains exhaust velocity without increasing back pressure. Two dryers cannot function on the same size exhaust as one. The best rule of thumb in manifolding (horizontal) is to allow 12 square inches of cross section plus 10%. Therefore, the following chart is suggested:
    2 dryers 12"x 2 = 24 + 10% = 27"or 6" round
    3 dryers 12"x 3 = 36 + 10% = 40"or 8" round
    4 dryers 12"x 4 = 48 + 10% = 53"or 8" round
    5 dryers 12"x 5 = 60 + 10% = 66"or 10"round
    6 dryers 12"x 6 = 72 + 10% = 80"or 10" round
  6. Somewhere in the laundry room, a clean-out should be introduced in the manifold.
  7. Vertical manifolds are effective for 35 feet (following the horizontal chart), but then should be increased 1" diameter for each additional floor. An exhaust fan (or booster) is effective and necessary for vertical systems (beyond 6 stories) but the booster motor must not be in the air flow.
  8. Back draft or bird and rodent protection cannot be accomplished with screen. Lint will clog any screen of less than 1/2" mesh.
  9. Individual entries into the manifold should be no greater than 45 degrees and in the direction of airflow. 90-degree entry is not acceptable. Two dryers should not make entry into a manifold at the same place.
  10. Flexible plastic ducting should never be used.

Double-load Dryers
Except for larger sizes and airflows, single-load dryer exhaust rules apply to double loaders, but they are commonly controlled by local codes as a "commercial" unit rather than a "home type". This necessitates code compliance.

Flexible ducting should not be used with double-load dryers as it creates a very high resistance ducting system.

MAKE-UP AIR

Make up air is the air that is brought into the room to replace that which has been exhausted by the dryers. Obviously, a double-load dryer exhausts more air than a single-load dryer does. Providing for the make-up air is particularly important where laundry rooms are located on every floor, since airtight fire doors are generally used.

Recommendations
  1. To replace the air exhausted, dryers require a minimum of one square inch of air space for each one thousand BTU, which the dryer produces. BTU output will vary, not only in relation to size of equipment but also according to the manufacturer, so it is necessary to assume the greatest BTU likely to be used.
  2. If outside air is used for replacement air, it must be preheated during cold weather. Therefore, it is desirable to use inside air (air within the building) as replacement air.
  3. In distributed laundry rooms, to replace air exhausted through dryers:
    1. For single-load dryers, use a 5" square duct with a 5" square adjustable louver for each laundry room.
    2. For double-load dryers, use a 10" square duct with a 10" square adjustable louver for each laundry room.
  4. In distributed laundry rooms with single-load dryers, install a fan on the roof, sized to provide air at the first floor at a rate of 250 CFM. With double-load dryers, install a fan on the roof sized to provide air at the first floor at a rate of 750 CFM. In a single, centralized laundry room, provide louvers or other openings at the ratio of one square inch for every thousand BTU produced by the dryers. In cold climates, louvers or other openings should be located on the interior walls of the laundry room.

These guidelines are for general informational and educational purposes only. They are not a nationwide standard established by the MLA. Local conditions may necessitate special adaptations. Also, state, county and city government statutory and code provisions should be checked to ascertain whether they require any variations in these guidelines. Although MLA intends to keep this information current and has taken reasonable efforts to ensure its accuracy, we do not guarantee that the information is correct, complete or up-to-date.

Visit the Multi-Housing Laundry Association for more information.