The code doesn’t set a maximum.
Attic vent chute requirements.
The full diameter of waste and linen chutes shall extend a minimum of 3 feet (0.92 m) above the building roof and be gravity vented in accordance with international mechanical code section 515.
This allows air to pass across the top of the vent.
Staples may not be needed where the insulation will hold the atticmate in place near the soffit.
Intake nfva (on soffits / undereave) 2.
Code requires that the chute is ﬁtted with a vent cap and that the cap is at least 48 inches above the roof.
The perimeter of the house should be properly vented into the attic and a proper ridge vent should also be continuous.the exterior walls should be sheated with 1/2 plywood and covered immediately with tyvek, mostly for the protection of the sheating.the interior of the outside walls should properly insulated with fg friction fit, all wall.
For best performance, the airspace in the vent chute should be a minimum of 2 in.
Vent chutes some boards to lay on (i chopped some to length for easier carrying) good breathing mask head light eye protection gloves, long sleeves, and long pants to keep insulation off your skin to find where your soffit vents are, go outside and look at the edge of your roofline anywhere there is an overhang.
(1500 ÷ 150 = 10) so if this is the minimum is it ok to have more?
In such roofs, moisture will tend to condense on the cold surface of the sheathing and framing members because it cannot dissipate over a large area as it can in attic roofs.
Ideally, the intake vents are installed along the edges of the roof, at the lowest point in the attic, in the soffits.
Most typical sizes are 16 and 24 to match open space between the roof framing members.
This means that if you have a 1500 sqattic then you would need at least 10 sfof ventilation.
Upper ventilators shall be located not more than 3 feet (914 mm) below the ridge or highest point of the space, measured vertically.
Federal housing authority recommends a minimum of 1 square foot of attic ventilation (evenly split between intake and exhaust) for every 300 square feet of attic floor space.
Ventilation requirements exhaust system products allow excess heat and moisture to exit the home.
Jm vent chutes are packaged in bags of 50 vents.
Attic, but you should know that