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Wire Size Calculator
Conductor size from the larger of the voltage-drop limit and the NEC 310.16 ampacity limit, for copper or aluminum.
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Water heating calculators
Tank size, tankless GPM, recovery, UEF running cost, and payback — each with visible math.
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Commercial Hot Water Demand Calculator
Peak hot water demand and the storage and heat input it implies for hotel rooms, apartments and restaurant seats, with recovery credited against the...
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Tank vs Tankless Water Heater Cost Calculator
Life-cycle cost of a storage tank against a tankless unit, counting tank replacements, maintenance and discounting over the horizon you choose.
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Heat Pump Water Heater Savings Calculator
Annual saving, payback and the space-cooling effect from an electric resistance to heat pump swap, screened against the installation ambient temperature.
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Recirculation Loop Cost Calculator
What a hot water recirculation loop costs to run: delta-T corrected pipe loss, separate pump energy, and the annual total.
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Water Heater Energy Cost Calculator
Annual and monthly cost for the fuel you actually use, with the DOE draw pattern as the usage basis and cost per 1,000 gallons.
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Hot Water Demand Calculator (GPM)
Design simultaneous hot water flow from editable fixture flows and a documented diversity factor, with the heat input it takes to hold it.
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Water Heater BTU Calculator
Heat input a batch of water needs inside a time window, in nameplate BTU/hr, kW, amps and MBH.
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Mixed Hot Water Capacity Calculator
Usable gallons at shower temperature from a hot tank: the per-gallon split, shower minutes, the equivalent tank at 120 F and the scald screen.
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Water Heater Heat-Up Time Calculator
How long a tank takes to reach its thermostat setting from the temperature the water is at now, and the input needed to hit...
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