A 30 x 40 ft.
Ventilate your attic.
A portable air conditioner is the easiest solution for cooling your attic.
Then aim for about 1 sq.
Rafter vents should be placed in your attic ceiling in between the rafters at the point where your attic ceiling meets your attic floor.
It extends the life of your shingles by keeping the roof cooler in hot weather.
Once they are in place you can then place the batts or blankets or blow insulation right out to the very edge of the attic floor.
That said air resistance and interference such as vent grates reduces the area of true ventilation.
Attic for example has an area of 1 200 sq.
Intake vents located at the lowest part of the roof under the eaves allow cool.
In other words the entire vent opening doesn t count as vented space.
Generally speaking you need a ratio of 1 300 where for every 300 square feet of ceiling space you need 1 square foot of attic ventilation.
The building code lets you reduce that by half under some conditions but more roof ventilation is usually better.
It s a standalone unit that s about two feet tall and 18 inches wide and has wheels for mobility.
It helps prevent ice dams in winter by keeping your roof colder.
Intake vents which are located at the down slope edge of the roof aka eave s and allow fresh air into the attic.
In of vent opening per 150 sq.
Most come with a window kit for this purpose that attaches to a hose on the back of the unit.
A well ventilated attic offers four benefits it prevents mildew growth and rot on your roof s framing and sheathing by reducing moisture buildup.
Portable air conditioners do need to be vented to pump the hot air outside.
Jones takes this measurement and divides it by 150 for a total of 7 36 square feet of ventilation space that is needed.
Jones has an attic space that measures 23 feet by 48 feet.
This will help to avoid premature damage to the shingles or mold building up in moist hot.
This yields a total area of 1 104 square feet.
If there are asphalt shingles on your roof the attic must be ventilated to comply with the terms of the manufacturer s warranty.
An attic fan works by exchanging the hot air in your attic space for fresh air pulled through the vents.
First determine your attic area by multiplying the length by the width.
To properly ventilate an attic two types of vents are needed.