More Vents Attic

The building code lets you reduce that by half under some conditions but more roof ventilation is usually better.

More vents attic.

Install rectangular roof vents on both sides of the roof. They re most effective when used in conjunction with a continuous ridge vent. This will help to avoid premature damage to the shingles or mold building up in moist hot. Figure 7 mechanical ventilation used with a hip roof.

If not measure the size yourself. Sure installing roof vents for older homes can reduce your hot air during the summer but there are probably more low risk cost effective ways to increase your home s energy efficiency. One method is to use a powered attic vent with a humidistat thermostat located close to the ridge or top of the roof. Effective attic ventilation systems reduce damaging heat and moisture in your attic promote energy efficiency by helping to reduce the load on your air conditioner in the summer and also reduce the risk of ice dam formation on your roof.

Good roof ventilation can do this but shingle color sun exposure and insulation are exponentially more important to overall energy efficiency than ventilation. Of course there should be intake vents to ensure a balanced system. Fans and vents may be installed on the roof system that will draw the air out of the attic space and exhaust it to the exterior. The open area of a vent is sometimes listed on the roof air vent as nfva net free vent area.

Rectangular roof vents installed on one side of the roof only. These vents allow outside air to enter the attic at the lowest point of the roof along the underside of the eave. And in many of these cases the hip roof forms a large volumetric attic space to ventilate. Intake vents located at the lowest part of the roof under the eaves allow cool.

If the slope of your roof is greater than 6 12 you will need more ventilation to reflect the extra volume of attic space. Many experts consider plugging these holes to be more important than ventilation. Calculate 20 per cent more for 7 12 to 10 12 pitches and 30 per cent more for a pitch that is 11 12 or greater. Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents.

Roof vents will provide about half of the vent area and soffit vents the other half. These fans may be controlled by a switch or a thermostat which detects heat build up in the attic space and automatically exhausts the attic space. Soffit vents come in several sizes and styles including small round discs and rectangular grilles. Whole house fans powered attic fans.