HVAC & Plumbing Calculators

Practical preliminary engineering calculators for HVAC and plumbing design, including duct pressure drop, ERV/HRV calculations, water flow, heating, cooling, water heater sizing, and psychrometric processes.

Use these tools for preliminary reference only. Final design should be verified by a qualified mechanical professional and applicable local codes.

Duct Pressure Drop Calculator

Estimate duct velocity, friction loss, equivalent length, and total pressure drop for preliminary ductwork design.

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ERV/HRV Calculator

Estimate supply air temperature and heat recovery performance using sensible, latent, and total effectiveness.

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Hydronic Flow & Pump Head Calculator

Estimate chilled water and heating water flow, pipe velocity, pipe pressure drop, equivalent length, and preliminary pump head for HVAC hydronic systems.


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Water Heater Sizing Calculator

Estimate domestic hot water demand, storage capacity, recovery rate, and preliminary electric water heater sizing.

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Psychrometric Process Calculator

Evaluate sensible heating, sensible cooling, cooling and dehumidification, humidification, and air mixing processes.

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Compressed Air Pipe Sizing Calculator

Estimate compressed air pipe size, velocity, pressure drop, equivalent length, and preliminary distribution-system performance.


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