Total Cost of Ownership Modelling

Electricity Consumption Model

The pool pump can be one of the larger power users around a home, especially if it runs long hours. Our model calculates pump energy consumption from first principles: Annual kWh = Pump Power (kW) × Daily Run Hours × 365 For variable-speed pumps, we model the actual speed profile (low speed for filtration, high speed for cleaning/heating) and apply the cubic power law to calculate weighted average consumption. Additional electrical loads include salt chlorinator cell power, robotic cleaner consumption, pool lighting, and automation controller standby power.

Chemical Consumption Estimation

Chemical costs depend on pool volume, sanitiser type, water temperature, bather load, and environmental factors. Our model estimates annual consumption of: • Chlorine/salt (sanitiser maintenance) • pH adjustment chemicals (acid/soda ash) • Alkalinity adjusters (sodium bicarbonate) • Stabiliser (cyanuric acid) top-up from dilution • Algaecide (preventive dosing schedule) • Clarifier/flocculent (seasonal use) The estimate scales chemical use by pool volume and expected seasonal demand.

Water Replacement Costs

Pools lose water through evaporation, splash-out, backwashing, and leakage. Our model calculates annual water replacement volume using the evaporation model (Penman equation for Melbourne climate) plus estimated mechanical losses. Water costs use entered or assumed Melbourne water charges. Your retailer and property charges may differ.

Equipment Lifecycle Costs

Major equipment has finite lifespans and eventual replacement costs. Our model amortises replacement costs over expected service life: • Pump: 8 to 12 years (single-speed) or 10 to 15 years (variable-speed) • Filter media: 5 to 7 years (sand), 2 to 3 years (cartridge) • Salt cell: 3 to 7 years depending on usage and maintenance • Heater: 8 to 15 years depending on type • Automation/controls: 10 to 15 years Annualised replacement cost = Replacement Price ÷ Expected Lifespan

• Equipment costs are estimates and should be checked against current supplier pricing.
• Installation labour factored into replacement costs
• Inflation adjustment for future replacement events
• Warranty period offsets for early-failure scenarios

Professional Service Costs

Regular professional servicing extends equipment life and maintains water quality. Our model includes: • Routine service visits (weekly/fortnightly/monthly options) • Annual equipment inspection and tune-up • Seasonal opening/closing services • Emergency call-out allowance (statistical average) Service costs are estimates only. Actual pricing depends on the work, access, parts and visit frequency.