Build a Factory Utility Load Register Before Adding Production Equipment

Start with the demand the factory must serve

A new machine can fit the floor plan and still fail to deliver its promised output. Its steam demand may arrive while another batch is heating. The water main may supply enough volume each day but struggle during a short fill. An air compressor may have spare flow capacity. Yet pressure at the machine can still fall below its required level.

A factory utility load register helps answer these questions before you commit to the new output. Each proposed load has a time, supply route and required service quality. The register links those needs to evidence. It should show what must change and who will check it, along with the conditions the decision covers.

This guide develops an illustrative addition of two batch washers. Every equipment rating, measured value, capacity and schedule in the example is fictional. The figures teach the review method. They are not machine specifications or suggested design limits. The case screens utility needs; the actual installation still needs technical approval.

Give each figure a location and an operating condition

Start the register at the point where a capacity decision will be made. That might be the electrical supply to a department, a steam header, an air branch or a treated-water line. A factory-wide total cannot reveal every local restriction.

For each supply, distinguish installed capacity from usable capacity in the stated condition. A boiler rating does not establish what reaches a distant user. A standby pump may share the same power supply as the duty pump. A compressor listed as spare may already support another area during its peak shift.

The capacity entry therefore needs a boundary, date and evidence reference. List the available supply units and the loads already included. State which operating conditions the checks covered. Record outages as separate cases. An unexplained percentage cut in a plant rating does not prove that a reserve exists.

Use one register entry per machine and utility. Link to the supporting profiles. A single spreadsheet cell need not hold a long technical report.

Label the basis of each entry: a supplier's requirement, a site measurement or an engineer's estimate. All can be useful, but they answer different questions. When a measurement replaces an estimate, keep the earlier entry. The team can then explain the change.

Build the timeline before applying a demand factor

Connected load is the sum of the equipment included in a boundary. Demand is what those loads require at a particular time or over a defined interval. Equipment may run below its rating, and its peaks may occur at different times. The distinction affects the load you need to serve.

Schneider Electric's guidance on maximum demand separates equipment use from simultaneous operation. The designer must choose suitable factors based on knowledge of the installation. A factor copied from an unrelated facility cannot replace that understanding.

For a small addition, a timeline is often easier to review than a single factor. Mark startup, steady running, cleaning and shutdown. Add the existing loads that could overlap with each stage. Also review restarts after an interruption. Several users may then request service together, unlike their normal starts.

Use a time interval short enough to capture the decision. A monthly bill can support a consumption budget, but it cannot show a five-minute fill peak. Conversely, a brief maximum reading does not establish annual energy use. Keep the peak-demand and consumption calculations separate, with their periods stated beside them.

Work through the steam profile of two new washers

In the fictional factory, existing steam demand at the chosen header is 600 kg/h throughout the study window. This includes existing users and the distribution losses assigned to that boundary. The verified usable supply is 1,200 kg/h in the specified normal plant condition.

Each new washer has a 60-minute thermal stage. At the same header boundary, each washer adds 400 kg/h for the first 15 minutes. It then adds 80 kg/h for the next 45 minutes. These figures already include the new branch losses assigned to the washer. Adding another loss allowance would count them twice.

The profile is deliberately simple. It is not a complete washing recipe, and the factory would need evidence for the real heating process. Spirax Sarco's steam-consumption guidance discusses calculation, measurement and equipment ratings. It distinguishes the initial heating load from the demand during operation. The time allowed for heating affects the required rate.

Simultaneous starts exceed the stated capacity

If both thermal stages begin together, the first 15-minute demand is:

600 + 400 + 400 = 1,400 kg/h.

The shortfall is 1,400 − 1,200 = 200 kg/h. After both washers move to their lower-demand stage, total demand becomes 600 + 80 + 80 = 760 kg/h. That later spare capacity does not undo the earlier peak.

Each washer's steam use for the thermal stage is:

(400 × 15 ÷ 60) + (80 × 45 ÷ 60) = 160 kg.

Together they use 320 kg in one hour. Adding this hourly average to the existing 600 kg/h gives 920 kg/h. That average appears to fit, yet the actual stated profile reaches 1,400 kg/h. Sizing the decision around the average would miss the problem.

Stagger the starts and follow the whole period

Now delay the second washer's complete sequence by 15 minutes. Time zero below is the start of the first washer's thermal stage. Each washer's fill takes place before its own thermal stage, as discussed later.

The peak is now 1,080 kg/h, leaving 120 kg/h against the stated normal capacity. Both washers still use 320 kg in total. The second thermal stage finishes at minute 75 instead of minute 60. The production schedule must allow for that change.

Over a common 75-minute comparison period, existing users consume 600 × 75 ÷ 60 = 750 kg. Adding the washers gives 1,070 kg under either start plan. This assumes no change in the existing load or the stated profiles. Staggering has reduced the peak; this calculation shows no steam saving.

A schedule is only a control if people and systems can maintain it. An operator catching up after a delay must not restart both sequences together without review. The production plan also needs to accept the later finish. If the factory cannot maintain that timing, it needs another solution. The spreadsheet alone cannot enforce the schedule.

Confirm steam conditions at the machine

The steam calculation checks mass flow at one boundary. It does not prove that the required heating conditions exist at either washer. The header flow may appear adequate. Even then, pressure losses, wet steam or poor air removal can affect heating.

Spirax Sarco's steam-quality guidance covers the quantity and pressure needed at the point of use. Steam must also be clean and suitably dry. The guide explains how air and other noncondensable gases can impair heat transfer.

Record the machine's required inlet conditions and how you plan to check them. The steam specialist should review the branch, controls and condensate arrangements as a system. A longer heating time is useful evidence of a problem, but it does not identify the cause on its own.

Also test the promised operating condition. Suppose usable supply falls to 900 kg/h during a defined equipment outage. The staggered peak of 1,080 kg/h exceeds it by 180 kg/h. Passing the normal-operation check does not show that both washers can run through this outage. The plant must state what production remains available in that condition.

Check electrical input and apparent power on the same basis

The fictional washers each have a rated electrical input of 22 kW. That is input power, not mechanical shaft output. Their expected input during the chosen coincident running condition is 16 kW each. A separate 6 kW allowance covers all added utility auxiliaries in that condition. It includes the relevant pumps and the extra compressor power.

This allowance is a planning assumption awaiting confirmation. The existing 250 kW site demand already includes the existing utility auxiliaries. Do not add them again. The new connected input allowance is therefore 22 + 22 + 6 = 50 kW. The planned operating increment is 16 + 16 + 6 = 38 kW.

For the selected condition, total real power is 250 + 38 = 288 kW. Assume the aggregate power factor at that boundary is 0.90. Apparent power is then:

288 ÷ 0.90 = 320 kVA.

Against a stated usable limit of 350 kVA, the arithmetic leaves 30 kVA. This is a preliminary steady-state comparison, subject to the assumptions being valid. It does not select a transformer, cable or protective device.

Schneider Electric's apparent-power guidance distinguishes motor efficiency from power factor. Efficiency relates output power to input power. Power factor relates real power to apparent power. Dividing an electrical input by motor efficiency again would apply the wrong basis.

The aggregate power factor in the example is an explicit assumption, not an average of nameplate values. At a power factor of 0.80, the same 288 kW would require 360 kVA. That exceeds the stated limit by 10 kVA. A measured or properly assessed value matters to the decision.

The electrical designer must also address starting behavior, power quality, protection and the distribution route. A steady-state total cannot settle those issues. State the operating scenarios covered by the study, including the factory's restart plan. A later reviewer can then see what the approval covers.

Keep air flow separate from air pressure and quality

The air check uses a common flow reference: dry air at 20°C and 1.00 bar absolute. These are the example's chosen reference conditions, not a universal definition for every supplier's flow figure. A volume measured in a pressurized pipe differs from a free-air figure. Put both on a common basis before adding them.

The existing coincident demand is 2.40 m³/min, including leaks already present in the measured baseline. Each washer adds 0.35 m³/min during the assessed condition. Total demand becomes 2.40 + 0.35 + 0.35 = 3.10 m³/min. The usable supply is 3.20 m³/min on the same reference basis, leaving only 0.10 m³/min.

That small positive difference does not establish a satisfactory service. Suppose the fictional commissioning trial records 6.8 bar gauge at the header but only 5.7 bar gauge at a washer during a demand burst. Its stated minimum inlet requirement is 6.0 bar gauge. The inlet condition fails even though the flow comparison was positive. Gauge and absolute pressure must remain clearly labeled.

The DOE compressed-air sourcebook treats air needs through quantity, pressure, quality and the load profile. Its glossary distinguishes actual flow from flow expressed at reference conditions. The same source discusses logging changes over time and the role of storage during brief demand events.

For this project, the low-pressure result remains an open engineering issue. A specialist would investigate the supply route, treatment equipment, controls and demand event before choosing a remedy. Storage may help with a short burst. The stored air will run down if demand stays above supply.

Record the supplier's required air quality and the evidence that the installation meets it. A higher header pressure cannot stand in for that check. Once these service checks are settled, review operating cost. The separate guide to pneumatic circuits and compressed-air cost can help with that assessment.

Calculate water peaks from the fill duration

Each washer in the example needs 1.5 m³ for a particular fill lasting five minutes. The fill finishes just before its 60-minute thermal stage begins. This calculation covers only the fill window, with no other new water draws. The full recipe must also include every later wash, rinse and cleaning stage.

The flow during one fill is:

1.5 ÷ (5 ÷ 60) = 18 m³/h.

If both fills happen together, new demand is 36 m³/h. Existing demand at the same branch is 10 m³/h during that window, so total demand reaches 46 m³/h. Against a stated usable supply of 40 m³/h, the shortfall is 6 m³/h.

Moving the second sequence 15 minutes later also separates these five-minute fills. One fill plus the existing demand totals 28 m³/h, leaving 12 m³/h in the stated window. The two fills still use 3 m³. As with steam, changing timing does not reduce the quantity required by the assumed process.

The water register should identify the source and quality required by each use. EPA's Water Management Planning guidance supports an inventory of water-using equipment and checks of meter units. It also covers operating patterns and a facility water balance. That planning method is useful here. Its example buildings do not serve as textile benchmarks.

A large tank may hold enough water for a fill. Its outlet or downstream treatment may still limit the flow. Equally, a pump may meet the fill rate only briefly because the tank cannot refill between batches. Record both the short demand window and the replenishment period. Review repeated cycles across the full planned shift. A successful first fill does not prove that the supply can keep up.

Include the return routes and treatment loads

Incoming services are only part of the addition. The plant must also handle condensate, wastewater and any heat or material that leaves the process. Some incoming water does not become wastewater at once. Returned streams also need checks before reuse.

Draw the boundary before balancing water. Distinguish external supply, internal reuse, discharge, evaporation, carryout and changes in stored volume. A reused stream can appear in the flow through a machine more than once, while it entered the factory only once. Counting every pass as a fresh withdrawal would misstate the requirement.

The treatment review needs more than an average discharge volume. Two recipes may produce different wastewater characteristics at the same flow. IFC's textile manufacturing EHS guidance explains how process inputs affect wastewater. Treatment must suit those streams. This technical guide does not replace the site's discharge permissions or an assessment of its current process.

Give the treatment owner the proposed recipes, batch volumes and discharge timing. Record the accepted operating envelope and any unresolved questions. Moving a fill peak can also move a later drain peak. Follow the batch through its return routes in the combined schedule. The review extends beyond the time when the inlet valves close.

Review the evidence behind small reserves

The size of the spare capacity must be read alongside the confidence in the inputs. A precise subtraction can still rest on uncertain data. The steam case leaves 120 kg/h at its planned peak. Relying on that reserve means relying on the existing load and both washer profiles.

Consider a separate sensitivity check for that peak. Suppose existing demand could be 70 kg/h higher in the relevant window. The first washer's lower-demand stage could be 10 kg/h higher. The second washer's heating stage could be 30 kg/h higher. Assume, for this check, that these changes can occur together.

The revised peak becomes 1,080 + 70 + 10 + 30 = 1,190 kg/h. Only 10 kg/h remains against the same 1,200 kg/h supply. These are hypothetical input ranges, not measured uncertainty limits or a probability forecast. They show which assumptions deserve attention before the team relies on the schedule.

The register's separate peaks may not occur together. Do not assume that they do. Ask which combinations are physically possible and which operating records support them. Where the relationship is unknown, leave it open and obtain the evidence needed to resolve it. An assumed overlap and a measured overlap should remain distinguishable.

The same reasoning applies to the air check's 0.10 m³/min difference. Can the flow data resolve a change that small? If not, the positive result gives little confidence. Review meter range, measurement conditions and the duration represented by each reading. Use this review to decide whether to take more measurements or change the design. A universal spare-capacity percentage cannot answer that question.

Make the approval conditions visible

The four checks have different outcomes in the fictional case. Keep the outcomes separate. A successful steam calculation does not resolve the air problem.

There is no justified overall approval yet. Production owns the proposed sequence, while engineering owns the service evidence. The process team owns the product and recipe requirements. For each open item, name the person who can close it. State what evidence that person needs.

During commissioning, compare predictions with readings taken on the same time basis. Link them to the actual machine state. Keep the product checks beside those readings. Lower demand may reflect a slower or incomplete process, rather than a successful change. Record any deviations and explain changes to the register. Do not silently revise the assumptions after the event.

A useful trial log makes a failed result traceable. For example, was a low-pressure event linked to filling, heating or another user's startup? The log should help answer that. Agree on the recording interval before the trial and retain the raw readings. A single average for the whole trial can hide the event you need to investigate.

The accepted record then becomes part of routine control. A changed recipe or more frequent batches can alter the result. So can a new shared load or a changed supply route. Maintenance plans should preserve the conditions that support the capacity decision. ApparelDiary's preventive and predictive maintenance guide helps frame that follow-through.

Before purchase, link the proposed output to a credible operating schedule. Confirm the required service at each connection. The load register should make that evidence easy to follow, with clear units, timing and boundaries. Keep any open conditions visible until the team has resolved them.

References

• Schneider Electric: Estimation of actual maximum kVA demand. Equipment use, simultaneous loads and the designer's selection of factors.

• Schneider Electric: Installed apparent power. Input power, motor efficiency and power factor.

• Spirax Sarco: Methods of estimating steam consumption. Heating and operating demand, measurement and rated information.

• Spirax Sarco: Steam quality. Conditions required at the point of use and effects on heat transfer.

• U.S. Department of Energy: Improving Compressed Air System Performance, third edition, 2016. Demand, pressure, quality, storage and flow terminology; official archived publication.

• U.S. EPA: WaterSense at Work, Water Management Planning, November 2023. Equipment inventory, metering, operating patterns and water balances.

• IFC: Environmental, Health, and Safety Guidelines for Textile Manufacturing, 2007. Process wastewater and water-use considerations; technical guidance with site-specific application.