Calculators

Estimate the required fresh air ventilation rate in CFM based on floor area, ceiling height, target air changes per hour, number of occupants, and activity level.

Estimate the airflow a fan should provide in cubic feet per minute (CFM) based on room size, ceiling height, desired air changes per hour, and ventilation efficiency.

Calculate air changes per hour (ACH) using room dimensions and airflow. ACH estimates how many times the total air volume in a room is replaced each hour.

Estimate the airflow in CFM required for a supply or return register based on room size, ceiling height, ventilation quality, and room usage. This helps size a register for general residential airflow planning.

Estimate the recommended attic fan airflow in CFM based on attic floor area, attic height, roof pitch, climate heat load, and sun exposure. This calculator uses a baseline air-exchange approach with adjustment factors for attic conditions.

Estimate the recommended whole house fan airflow in CFM based on home floor area, ceiling height, desired air changes per hour, and a climate/ventilation factor.

Estimate the recommended range hood airflow in CFM based on cooktop width, stove type, cooking style, and duct run length. This calculator provides a practical sizing estimate for residential kitchen ventilation.

Estimate the recommended kitchen range hood airflow in CFM based on cooktop width, cooking surface type, cooking intensity, hood mounting style, and duct length.

Estimate the recommended bathroom exhaust fan capacity in CFM based on room dimensions, ceiling height, and how many times per hour you want the air exchanged.

Estimate the required exhaust fan airflow in CFM based on room dimensions, desired air changes per hour, and ventilation effectiveness.

Calculate required airflow in CFM based on floor area, ceiling height, desired air changes per hour, occupancy load, and ventilation intensity factor.

Estimate the total installed cost for duct wrap insulation based on duct surface area, wrap thickness, insulation material, job complexity, and labor rate. Surface area should reflect the total exterior square footage of ductwork to be wrapped.

Calculate the recommended airflow in CFM for a room based on room dimensions, ceiling height, and desired air changes per hour.

Estimate airflow in cubic feet per minute based on room size, ceiling height, air changes per hour, and system efficiency. Useful for HVAC ventilation planning and sizing airflow requirements for residential or light commercial spaces.

Estimate required HVAC airflow in CFM based on room size, ceiling height, desired air changes per hour, and a system/load factor.

Estimate airflow in cubic feet per minute (CFM) for a room using room size, ceiling height, target air changes per hour, and a system factor for typical ventilation or HVAC applications.

Calculate the true length of a duct offset using rise, run, number of elbows, and fitting angle multiplier. Useful for estimating material length needed for an offset section in HVAC ductwork.

Estimate the maximum equivalent duct length allowed for a ventilation run based on fan rated maximum equivalent length, duct diameter, number of elbows, and wall cap type. The result reflects a common equivalent-length approach where fittings and smaller duct sizes reduce the straight duct length available.

Estimate recommended round branch duct diameter based on required airflow, target friction rate, effective duct length, and fitting losses using a simplified residential HVAC sizing approach.

Estimate the recommended rectangular HVAC trunk duct size based on total airflow, target friction rate, duct aspect ratio, and design velocity. This calculator helps size a main supply trunk by calculating the required duct cross-sectional area and resulting equivalent trunk width for a chosen height-to-width ratio.

Estimate the total cost to insulate HVAC ductwork based on duct length, duct perimeter, insulation thickness, insulation material, and installation difficulty.

Calculate air velocity in a duct using airflow and duct dimensions. Supports rectangular and round ducts by applying a shape factor to the cross-sectional area.

Estimate the cost of residential air duct cleaning based on home size, number of vents, HVAC systems, contamination level, and accessibility.

Estimate the total cost to replace residential HVAC ductwork based on home size, duct layout complexity, duct material, accessibility, and local labor cost factor.

Estimate the installed cost of HVAC ductwork based on duct length, duct type, home accessibility, project complexity, and regional labor pricing.

Estimate the weight of a rectangular sheet metal duct section using its dimensions, length, material thickness, and material density.

Estimate total duct air leakage in CFM based on duct surface area, leakage rate, system pressure, and duct condition.

Estimate total external static pressure in a duct system using straight duct length, equivalent fitting length, airflow, and duct area. The calculation uses velocity pressure and a friction rate approach to approximate the pressure drop across the duct run.

Estimate duct friction loss using airflow, duct length, equivalent diameter, duct material, and fitting allowance. This calculator uses a practical HVAC approximation where friction loss increases with airflow and duct roughness, and decreases with larger duct diameter.

Estimate pressure drop in HVAC ductwork using airflow, duct length, hydraulic diameter, air density, and duct roughness factor based on the Darcy-Weisbach relationship.