Milnor regularly receives requests for washer extractor water consumption along with supply plumbing and discharge plumbing specifications.
First you need to know the wash capacity of the machine. Ratings like 60 lbs., 140 lbs., etc., should be on the Machine Data Sheet.
Most of the answers to questions like these revolve around a few key pieces of data.
- The normal washer extractor will consume approximately 2.5 gallons of water per pound of linen produced. There will be 5 to 6 fills and drains of water in the wash cycle.
- The normal cycle time for a washer extractor is about 45 minutes.
- You should consider the possibility that all the water consumed will be hot when sizing the hot water heater. This will provide a safety factor for the heater sizing.
- The normal fill time is approximately 1 minute.
- The normal drain time is about 1 minute but the volume discharged will be greater at the beginning of the drain time. Consider that approximately 80 percent of the water may discharge in the first 30 seconds. The machine uses a gravity drain so the most flow will occur at the very beginning of the drain time since there is more head pressure on the water when the drain is first opened.
- The normal number of fills with water is 5 in 45 minutes.
- If longer formulas are run, the cycle time will expand, but the requirement per hour of water supplied will be at the same ratio as the calculation for the 45 minute, 5 fill formula.
- The first fill may be larger than the later fills as the goods absorb water during the first fill only.
A single machine install can be plumbed directly to the sewer through a 3 or 4 inch pipe. If multiple machines are installed, you should consider a pit or trough to accept the surge of drained water as more than 1 machine can discharge at the same time. Size the trough to include all machines draining simultaneously. In the event of a power outage, all machines will drain immediately.
