Laundry Water, Sewer, and Energy Cost per Pound

Cost per pound is the number that decides whether to wash in house or send it out, and it has six parts that get counted very unevenly. Water and sewer are always counted. The energy to heat the wash water and the energy to evaporate the water out of the linen usually are not, and together they are the larger share of the utility bill: at 1.8 gallons per pound heated from 60 to 140 degF, and 45% retained moisture dried at 70% efficiency, the two energy lines are 37% of the utilities against 63% for the water and sewer people look at. Sewer deserves its own caution, because it is often billed on water consumed and is frequently the larger of the two rates, so a reuse or ozone system saves on both lines at once. Labor exceeds all of it. In most on-premise laundries labor is half or more of the cost per pound, which means a cost-per-pound figure that omits labor makes in-house laundry look far cheaper than outsourcing -- and that is the error that actually gets made. The lever with the best return is extraction. Water removed mechanically costs roughly a tenth of water evaporated, so dropping retained moisture from 45% to 35% takes the drying line from $0.0069 to $0.0054 a pound, worth $1,851 a year at 4,000 lb a day over 300 days, from the washer's extract speed rather than from anything the dryer does. A cost model from rates and factors the user supplies, and only as good as they are: gallons per pound and retained moisture vary widely with the equipment, the wash formula, and the classification of goods, and should be measured rather than assumed. It excludes equipment depreciation, maintenance, water treatment, and the linen replacement driven by wash severity, which on a healthcare account can exceed the utility cost. It does not evaluate water reuse, ozone, or heat recovery systems, and it does not address the compliance costs of healthcare or food-service laundry. A comparison against commercial laundry service pricing must account for what that price includes, which is usually linen, delivery, and loss replacement. The utility tariffs, the chemical supplier, and the equipment manufacturer's data govern.

cost per pound = gal/lb x (water rate + sewer rate) + gal/lb x hot fraction x 8.34 x (wash temp - incoming temp) / heater efficiency x fuel cost + retained moisture x 1,200 / dryer efficiency x fuel cost + chemical cost per hundredweight / 100 + labor hours x labor rate / pounds per day.

The component cost build-up as standard laundry practice, by name, with the 1,200 BTU per pound of water evaporated figure covering latent heat plus the sensible heat of the water and typical exhaust losses. The utility tariffs, the chemical supplier, and the equipment manufacturer's data govern.

A cost model from rates and factors the user supplies; no tariff or price list is reproduced.

Estimate. AHJ and licensed professional govern.

Field names used by the API: lb_per_day, gal_per_lb, water_rate_per_gal, sewer_rate_per_gal, incoming_temp_f, wash_temp_f, hot_fraction, heater_efficiency, fuel_cost_per_mmbtu, retained_moisture_fraction, improved_retained_moisture_fraction, dryer_efficiency, chem_cost_per_cwt, labor_hours_per_day, labor_rate_per_hour, days_per_year, hot_water_btu_per_lb, drying_btu_per_lb, utilities_cost_per_lb, energy_share_of_utilities_pct, total_cost_per_lb, extraction_saving_annual

• 1,200 BTU per pound of water latent plus sensible plus typical exhaust lossstandard laundry practice
• Depreciation and maintenance excluded as is linen replacement driven by wash severitycost model scope
• Service pricing includes more linen, delivery, and loss replacement are usually in an outsourced pricecommercial laundry practice