HVAC & Energy Calculators

Distributes a system's airflow room by room from each room's load and sizes the registers. Use it to balance supply airflow across a home.

Sizes an off-grid or backup battery bank from the load, autonomy, depth of discharge, round-trip efficiency and temperature derate. Use it to specify a battery bank.

Sizes ductwork by the equal-friction method, reporting velocity, friction rate and the required round or equivalent rectangular size, in IP or SI. Use it to size a duct run.

Estimates a building's sensible and latent heating and cooling loads from its envelope, occupancy and design conditions, in IP or SI. Use it for a whole-house load estimate and equipment sizing.

Computes moist-air properties such as wet-bulb, humidity ratio, enthalpy and dew point from two known properties, in IP or SI units. Use it for HVAC air-state calculations.

Models a solar PV system's production, bill savings and 25-year cash flow to report simple and discounted payback, return on investment, net present value and levelised cost of energy. Use it to evaluate a solar investment.