Energy Budget — Fitzroy Spawning Facility

Duty % covers cycling loads (chiller and aircon compressors, fridges). Schedule: 24/7 runs 24 h with night hours set automatically from night length. Day runs only in the solar window. Night runs entirely on battery. Custom lets you set both run hours and how many of those fall at night.

Thermal load is flow × 4.186 kJ/kg·K × temperature drop, applied to the full pass. The heat recovery HX models a plate exchanger pre cooling incoming seawater against the tank overflow stream before the chillers — reservoir head drives the intake side, tank rim head drives the waste side, LED cooling water joins the drain downstream of it. Effectiveness is the fraction of the raw drop removed and only applies when the toggle is on. Series chillers split the remaining drop evenly. Months already at or below target show zero load and run fully open.

Vent heat recovery is the ERV effectiveness (0 = none, 0.6–0.75 typical) applied to the fresh air load — only valid for enclosed rooms with ducted fresh air. Fabric load uses the panel U value on the sloped roof (with solar gain temperature lift) plus the outer long wall and both trapezoid end walls; the high middle wall is shared between conditioned rooms and excluded. Ventilation is costed with the Cairns latent penalty (~0.028 kW per L/s at the default 8°C rise). Tank evaporation is latent load the aircon removes as condensate — the same evaporation cools the water and offsets the chillers. Apply writes cooling-derived electrical draw to the matching aircon row.

For cut stock like aluminium extrusion, PEX liner, cable and LED neon. Pieces is how many lengths each tank (or the site) needs — e.g. 6 light bars of 2.4 m per tank from 6 m extrusion. Stock needed is rounded up from whole pieces per stock length; offcut shows the waste. Costs feed the capital total.

Load per month is the equipment total with the chiller row replaced by that month's capacity-capped chiller demand. Yield uses the installed array (or the computed requirement when set to auto) with derate and shade applied. Deficit months are carried by the resort generator via the battery charger.