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EspañolIf you know your daily linen volume, the number of washer-extractors you need comes down to five numbers multiplied together: effective operating hours, cycle time, rated capacity, loading rate, and a redundancy margin. Get any one of them wrong and you’ll either overbuy floor space or run a laundry that can’t clear its own daily load. This walkthrough runs the full calculation start to finish using one worked example: a mid-size hotel laundry processing 3,000 kg (3 tonnes) of mixed linen a day, so you can swap in your own numbers at each step.
Start With Your Daily Processing Volume, Not Your Room Count
Room count and bed count are useful for a rough first estimate, but they are only stand-ins. What actually drives equipment sizing is daily processing volume in kilograms, because that’s the unit washer-extractor capacity is rated in.
Worked example: a mid-size hotel laundry handles 3,000 kg/day of mixed linen (bed sheets, duvet covers, and bath towels combined into one wash schedule).
Every step below converts that single number into a machine count. If your own facility runs 8,000 kg/day or 1,000 kg/day, the same formulas apply; only the inputs change. If a room count is all you have right now, our hotel laundry room planning guide converts room count into a daily kilogram figure first; this walkthrough picks up from that number.
Convert Daily Volume Into an Hourly Requirement
A washer-extractor doesn’t process a “day”; it processes cycles, hour by hour. So the first conversion is daily volume into an hourly throughput target, based on how many hours the laundry actually operates.
Required hourly throughput = Daily processing volume ÷ Effective operating hours
Most in-house hotel laundries run somewhere between one and two shifts, commonly around 12 hours a day, long enough to clear the day’s turnover without paying for an overnight crew. Using 12 effective hours:
3,000 kg ÷ 12 h = 250 kg/h required
This number is the single most sensitive input in the whole calculation, and it’s worth stress-testing before you commit to a machine count. Run the same 3,000 kg/day on a single 8-hour shift instead, and the requirement jumps to 375 kg/h, which takes the fleet from four machines to six. Extend to a 16-hour double shift and the requirement drops to about 190 kg/h, which still does not take the fleet below four, because the round-up and the standby unit both hold. Before finalizing a capacity plan, confirm the operating window with whoever runs the laundry floor; shift length changes the answer more than any other variable in this walkthrough.
How Long Does One Wash Cycle Actually Take?
A full wash cycle (fill, wash, rinse, extract, plus load and unload time) typically runs about 60 minutes for a standard commercial program. That 60 minutes covers the wash cycle itself plus loading and unloading, with the short gap between batches that any real crew has; it is the planning value used consistently across hotel- and hospital-scale project calculations.
Cycles per hour per machine = 60 minutes ÷ cycle time
At the standard 60-minute cycle, that’s a clean 1 cycle per hour per machine, which keeps the rest of the math simple and is the assumption used in the worked example below.
Effective Capacity Per Cycle: Loading Rate Matters
A washer-extractor’s rated capacity (say, 100 kg for an XGQ-100F) is the maximum drum load, not the number you should plan around. Day-to-day commercial operation runs at a loading rate of 90-95%, with 92.5% as a common planning midpoint. Underload consistently and you waste cycles; overload and you shorten machine life and hurt wash quality.
Effective load per cycle = Rated capacity × Loading rate
| Model | Rated capacity | Effective load at 92.5% |
|---|---|---|
| XGQ-50F | 50 kg | 46.3 kg |
| XGQ-100F | 100 kg | 92.5 kg |
| SXT-100FQ | 100 kg | 92.5 kg |
| SXT-120FQ | 120 kg | 111 kg |
| GLX-50 (barrier) | 50 kg | 46.3 kg |
| GLX-100 (barrier) | 100 kg | 92.5 kg |
Rated capacity itself is a trade-off: fewer large machines mean less floor space and fewer water, steam, and drain connections, while more small machines give finer batch granularity for separating linen types and leave a smaller hole when one unit is down. For a single mixed-linen wash schedule at this volume, the 100 kg class is the usual starting point.
For the worked example, the standard commercial workhorse (the XGQ-100F, from the large-commercial XGQ line that has been HOZO’s highest-volume range for three decades) is the natural starting point: 100 kg × 92.5% = 92.5 kg effective load per cycle.
Calculate the Machine Count: the Full Formula
With hourly requirement, cycle time, and effective load in hand, the base machine count is one division:
Machines required = Required hourly throughput ÷ (Effective load per cycle × Cycles per hour)
Working the example:
- Hourly throughput per machine = 92.5 kg × 1 cycle/h = 92.5 kg/h
- Machines required = 250 kg/h ÷ 92.5 kg/h = 2.7 → round up to 3
Always round up, never down: a fractional machine means the fleet physically cannot clear the daily volume within the operating window, and the shortfall compounds daily.
Add N+1 Redundancy Before You Finalize the Number
Three machines running at full utilization with zero spare capacity means one breakdown, one scheduled service, or one unusually heavy laundry day stalls the entire operation. Standard facility-engineering practice is to add at least one standby unit above the calculated minimum (commonly written as N+1) so routine maintenance or a single machine going down doesn’t take out the laundry’s ability to hit its daily volume.
Total machines = Base machines required + 1 (minimum standby)
For the worked example: 3 + 1 = 4 × XGQ-100F, giving the laundry a working buffer instead of running every unit at the ragged edge of its duty cycle every single day. Facilities running closer to continuous, three-shift operation should plan for more than one spare, since downtime risk compounds with utilization.
When Standard XGQ Isn’t Enough: Sizing Into SXT or GLX
The formula above doesn’t change once volume grows; only the machine you plug into it does. HOZO’s washer-extractor range covers a standard 15-120 kg span across four sub-series, with larger capacities available on request for non-standard projects.
| Sub-series | Capacity | What changes the math |
|---|---|---|
| XGQ small-commercial (15F/20F/25F) | 15-25 kg | Lower daily volumes: self-service laundromats, dry-cleaning outlets, small linen points |
| XGQ large-commercial (30F/50F/100F) | 30-100 kg | The default input for most hotel, school, and mid-size laundry sizing runs |
| SXT tilting heavy-duty (100FQ/120FQ) | 100-120 kg | 18° tilt discharge and near-continuous duty cycles, not capacity alone |
| GLX barrier (50/100) | 50-100 kg | A hard requirement (infection control), not a volume threshold |
SXT trigger: once a facility’s daily volume pushes toward several large XGQ-100F units running back-to-back, high-frequency, high-intensity duty cycles (typically large hotels, resorts, or central laundry plants), the SXT-100FQ/120FQ’s 18° tilt discharge and automatic lubrication reduce manual unloading strain and are built for continuous operation. The capacity math above stays exactly the same; what changes is unload effort and the duty cycle the machine is rated for.
GLX trigger: barrier (isolation) washing gets decided by the infection-control requirement, before any volume number enters the picture. If soiled and clean linen need physical separation (hospitals, food processing, pharmaceutical, or the hospital-service line inside a central plant), a single-chamber double-door GLX-50 or GLX-100 replaces the equivalent XGQ or SXT unit in the same formula, with the barrier wall as an added facility-layout constraint rather than an extra variable in the sizing math itself.
Once the washer-extractor count is set, the next planning question is usually operating cost; see our hotel laundry cost-per-kilogram calculation guide for how machine count, cycle time, and utility rates roll up into a per-kilogram figure. For facilities scaling past a single laundry room into a full plant layout, our industrial laundry plant equipment guide covers how washing, drying, and finishing stages connect on the floor. Full capacity tables for every model in the range are in HOZO’s washer-extractor product line.
FAQ
How do I size washer-extractors for mixed linen loads?
Mixed loads (sheets, duvet covers, and towels run together) are the standard case this walkthrough assumes, and the 90-95% loading rate already accounts for the lower packing density of bulky items like duvet covers next to flatter sheets. Kitchen linen and industrial workwear are usually washed on their own programs rather than mixed into the guest-room schedule, so confirm the actual cycle time your operator plans to run for those loads before applying the cycles-per-hour step.
When does the extra N+1 machine pay for itself?
A single N+1 spare machine on a 3-4 unit fleet is inexpensive insurance against one bad day. As fleet size and utilization grow (multi-shift central plants running 16+ hours a day), the case for a second spare gets stronger, because downtime on a highly utilized fleet has nowhere to be absorbed. What the spare costs matters less than what one full day of missed throughput costs the business.
Should I add more machines or move up a size?
If the base machine count from the formula above keeps climbing past 5-6 units of the same standard model, it’s worth re-running the math with a larger unit (SXT-100FQ/120FQ) instead of adding more XGQ-100F units: fewer, larger machines running the same total hourly throughput mean less floor space, fewer connection points for water/steam/drain, and less manual handling per kilogram processed.
About the Author: HOZO Engineering Team, 30+ years of industrial laundry equipment manufacturing experience.
