Professional HVAC engineering tools for duct sizing, cooling loads, ventilation, and system design per ASHRAE standards.
World-class duct sizing with visualization, SMACNA compliance, noise criteria
Size round and rectangular ducts using velocity or equal friction method
Convert cooling tonnage to airflow rate
Find the right AC size for a room — BTU/hr, tons & kW from area, climate, sun, insulation & occupancy
Size chilled water pipes using ASHRAE limits (≤2″: 4 ft/s, >2″: 4 ft/100ft). US & Metric modes with velocity and head loss.
Multi-zone cooling & heating load (ASHRAE CLTD) — sensible/latent, TR, kW, SHR, supply CFM with whole-building rollup & diversity
Calculate fresh air requirements based on air changes per hour
Find what size AC you need in tons & BTU from room area, climate, insulation & sun — with quick estimate and detailed load modes
Calculate dew point & condensation risk from temperature and RH or wet bulb — with humidity ratio, enthalpy & altitude correction
Estimate room cooling/heating load
Detailed heat load calculation per E20 method
Convert CFM, CMH, L/s and other airflow units
Calculate duct friction loss and velocity
Calculate fan static pressure requirements
Calculate AHU fan motor power
Size AC condensate drain pipes
Condensate flow (latent or rule-of-thumb), IMC pipe size, gravity capacity check, P-trap depth, water recovery & condensate-pump sizing
Select cooling coils based on load
Calculate air properties and psychrometric processes
Size variable air volume boxes
Calculate kitchen exhaust hood airflow
Calculate smoke exhaust requirements per NFPA 92
Calculate chiller capacity requirements
Size cooling towers and calculate makeup water
Calculate pipe size, velocity, friction factor, head loss, elbow loss, and pipe + fluid weight
Size copper suction, liquid & discharge lines — velocity, pressure drop & ΔT penalty for R410A, R32, R134a, R404A, R22 & R407C with oil-return checks
Size boiler feed water pumps — flow (m³/hr, GPM), total head & motor kW/HP from boiler capacity & pressure with IEC motor selection
Sheet metal area, SMACNA gauge and weight for rectangular & round duct
ASHRAE 90.1 minimum thickness plus chilled-water condensation check
Cold storage and freezer refrigeration load in kW / TR
Max R-32 / R-454B charge or minimum room area (IEC 60335-2-40)
Saturation pressure-temperature chart for R410A, R32, R22, R134a and more
Log mean temperature difference, heat duty and heat exchanger area
Ceiling diffuser neck size and grille size from airflow and noise level
Air conditioner kWh and electricity cost per day, month and year
New airflow, pressure and power when fan speed changes
Basement parking exhaust by 6/10 ACH and ASHRAE 62.1, with jet fans
Superheat, subcooling, target superheat and charge check for R410A, R454B, R32 and more
Heat pump size in tons or kW from heat loss and climate, with balance point and backup heat
Size a full duct network: index run, fan ESP, balancing and sheet metal BOQ
Our HVAC calculators help engineers design efficient heating, ventilation, and air conditioning systems. All calculations follow ASHRAE handbook guidelines and industry best practices.
Size supply and return ducts using velocity method or equal friction method. Calculate round, rectangular, and flat oval duct dimensions with proper aspect ratios.
Estimate room and building cooling loads using simplified methods or detailed E20 calculations. Convert between TR, BTU, and kW.
Calculate fresh air requirements based on occupancy, air changes per hour, and ASHRAE 62.1 standards. Design kitchen exhaust and smoke control systems.