Free, no-signup calculators and selectors for engineers and facility managers specifying air-to-air heat exchangers and waste-heat recovery.
Estimate annual energy, cost and CO₂ savings + payback from a heat recovery ventilator.
Open → SelectorAnswer 4 questions to get the right type: plate, rotary wheel, cross-flow or heat pipe.
Open → CalculatorDry-bulb + RH → dew point, wet-bulb, humidity ratio, enthalpy, specific volume.
Open → CalculatorFriction + fitting pressure drop for round or rectangular ducts — size your fan.
Open → CalculatorRound diameter or equivalent rectangular sides from airflow and a target velocity.
Open → CalculatorRecover dryer / oven exhaust heat to pre-heat make-up air; see the payback.
Open → ReferencePlate vs rotary vs cross-flow vs heat pipe — effectiveness, cost, best use.
Open → CalculatorSimple payback, ROI and 10-year NPV from duty and installed cost.
Open → CalculatorSensible and enthalpy effectiveness from inlet/outlet temp and humidity.
Open → CalculatorEffectiveness from NTU and capacity ratio for counter, parallel and crossflow.
Open → ConverterLive unit converter: CFM, m³/h, L/s, m³/s and air mass flow.
Open → CalculatorExhaust outlet temp, dew point and the outdoor temperature where frost begins.
Open → CalculatorCore area, face area and depth from airflow and target effectiveness.
Open → ESGtCO₂e avoided per year and tree / car equivalences from recovered energy.
Open → CalculatorEnvelope + ventilation load, comparing with vs without heat recovery.
Open →Engineers and buyers search for calculators and selectors by intent (“heat exchanger payback”, “duct friction loss”). These tools answer real questions, earn backlinks, and feed qualified enquiries to our team. Start with the Savings Calculator or the Selector.