Underfloor Ventilation Calculator

Ventilate the underfloor space by providing ventilation in two opposing external walls.

Underfloor ventilation calculator.

By stephen sargent branz technical writer a figure 1. This example shows how to calculate the minimum clear openings necessary to meet the required ventilation rate of 3 500 mm 2 m of floor area. Let owens corning roofing help you calculate exactly how much ventilation you will need for a healthy and balanced attic with our 4 step ventilation calculator. Calculate or enter the square footage of the attic or area to be vented.

If local code requires the 1 150 rule please double the requirements. Compliance with attic ventilation code requirements should always be verified at the local governing level before performing the following calculations. The ventilation calculator will help you choose the correct airmaster ventilation unit according to room size and usage. Proper attic ventilation consists of a balance between air intake at your eaves soffits or fascias and air exhaust at or near your roof ridge.

By contrast the wire mesh vent shown here has a ventilation area of 14 200 mm 2. All lomanco attic ventilation product requirements are based on the minimum standard 1 300 rule as set forth by the international building code ibc and the international residential code irc. Total ventilation required for this 10 m square. This inadequate ventilation can cause some serious problems.

24 ventilation openings required example. Annual energy consumption based on usage and requested temperature for the chosen ventilation units can be calculated with the energy calculator. Federal housing authority recommends a minimum of at least 1 square foot of attic ventilation evenly split between intake and exhaust for every 300 square feet of attic floor space. Crawl space ventilation calculation r408 1 section r408 1 specifies that the crawl space under floor space which is the area between the bottom of the floor joists and the earth under the building not including the basement must have ventilation openings through the foundation walls or exterior walls.

These methods dictate that one 1 square foot of ventilation is provided for every 150 or 300 square feet of attic floor space. Vent calculator design your balanced ventilation system. Click on the link below to see an example of how to use the bca table to calculate the number of vents needed in a wall. Rytons underfloor ventilation calculator for effective sub floor ventilation.