by Pat Holiday
It is necessary to determine what the total investment will be as well as the ongoing operating cost of an OPL. As expected, an ISO Class 3 is the most expensive and an ISO Class 6 will be less expensive. This cost increase that occurs in the ISO Class 3-5 ranges is due to the need of a pass-through (barrier wall) washer. The pass-through machines are on average two to three times as expensive as an open pocket (front-loading) washer that can be used in less stringent environments.
Process control, another key factor in creating an OPL, is especially important in the pharmaceutical industry. Pharmaceutical companies are drying items other than cleanroom gowns, and this may require a dryer with special features such as speed control of the cylinder (basket), all wetted parts, stainless steel construction, a drain for excess liquids and HEPA filters that not only filter out bacteria but also kill bacteria.
Deionized (DI) water is also used and adds cost for the equipment, extra plumbing to circulate the water and ultra-violet light to kill bacteria that builds up in ultra-pure DI water. Since DI water is “ion hungry,” 316L stainless steel is most often used, which in turn, adds an additional cost to the washer.
The typical cost for a 600-liter (20 cu. ft.), 57-kg (125-lb), ISO Class 3-5 pass-through washer in the example above is $55,000 to $60,000. This includes the 316L stainless steel, stainless steel water valves for hot and cold reverse osmosis (RO) water and cold DI water.
A chemical dosing (dispensing) system is also required for the cleanroom washer. An automatic dosing system is more accurate and consistent than a manual system. Also, a manual system is difficult to keep clean and control the air exchange between the washer and air in the room.
The typical cost of a 1,400-liter (50 cu. ft.), 77-kg (170-lb), ISO Class 3-5 cleanroom dryer is $25,000 to $30,000. This includes stainless steel for all wetted surfaces, a HEPA filter, a quality HEPA filter enclosure, microprocessor control and air sample ports. On smaller laundries, electric heated dryers are available. Also, two electric dryers can be used in place of one large gas or steam-heated dryer.
On average, a small cleanroom laundry will require 800 sq. ft. of cleanroom space including a small gowning room, two pass-through ports, entrance door, emergency door, lights and a control panel for the HVAC and filtration system.
If steam boiling and hot water are not available, a 20-horsepower packaged boiler will cost approximately $15,000 to $25,000 including installation. An alternative is to use gas-heated hot water heaters and a gas-heated cleanroom dryer with a stainless steel heat exchanger. This eliminates particles of combustion, CO, aldehydes and nitrous oxide from entering the dryer or the HEPA filter system.
Reverse osmosis (RO) water is required for washing. On ISO Class 3-4 laundries, ultra-pure DI water is also required. The price for a 10-gpm system can range from $250,000 to $400,000 including installation. This includes hot and cold RO water as well as the cost of a mixed bed polisher for DI water.
A portable exchange program using regenerated tanks is often used for DI water. A regenerated 20 cu. ft. tank costs approximately $1,500 and is good for 125,000 gal of DI water. Most OPL laundries use a rental system as a RO, and ultra-pure DI water producing systems can be cost prohibitive. The rental cost varies from $3,000 to $5,000 per month.
Finally, it is necessary to have perforated stainless steel folding tables, laundry carts, and a bag sealer to complete the basic package. Stainless steel tables for folding the garments are $1,500 each, while a 22 cu. ft. (20 Bu) polyurethane cleanroom laundry cart is $500 and a 20-inch bag sealer with ported exhaust and stand are $4,000.
A recap of the above costs is as follows:
|
null
The above recap should help estimate the initial capital investment. It is also necessary to consider the operational costs. The main items are labor, utilities and maintenance. Labor costs and overhead varies, but three to four people working 40 hours will process 4,000 garments per week with the equipment and facilities listed above. Utilities costs vary, however, the dryer will use more than 10,000,000 BTU per week.
It's easy to see why most companies use an outside processor. The July 2001 article in Cleanrooms contained an excellent checklist on choosing a cleanroom apparel service provider. However, if you have the space and are ready to make the investment, moving this critical competency in-house will certainly give you more control over the process and save money in the long term.
P. D. (Pat) Holiday is president of Streetman, TX-based Ultra Clean Laundry Equipment Co., a cleanroom laundry equipment company with a focus on the semiconductor and pharmaceutical industries. Holiday can be reached at [email protected].